Bump to 2025.8.2

* Fix linkify placeholders

* Add URL test

README.rst

@@ -8,6 +8,7 @@ pretix
    :target: https://docs.pretix.eu/
 
 .. image:: https://github.com/pretix/pretix/workflows/Tests/badge.svg
+   :target: https://github.com/pretix/pretix/actions/workflows/tests.yml
 
 .. image:: https://codecov.io/gh/pretix/pretix/branch/master/graph/badge.svg
    :target: https://codecov.io/gh/pretix/pretix

doc/api/fundamentals.rst

@@ -203,35 +203,9 @@ Query parameters
 Most list endpoints allow a filtering of the results using query parameters. In this case, booleans should be passed
 as the string values ``true`` and ``false``.
 
-Ordering
---------
-
 If the ``ordering`` parameter is documented for a resource, you can use it to sort the result set by one of the allowed
 fields. Prepend a ``-`` to the field name to reverse the sort order.
 
-Filtering and expanding fields
-------------------------------
-
-On many endpoints, you can modify what fields are being returned:
-
-- Using the ``include`` query parameter, you can chose which fields will be returned as part of the response.
-  For example, if you pass ``include=code&include=email`` to the list of orders, you will receive a list of only
-  order codes and email addresses.
-
-- Using the ``exclude`` query parameter, you can chose which fields will not be returned as part of the response.
-  For example, if you pass ``exclude=payments&exclude=refunds`` to the list of orders, you will receive a list
-  without the payment and refund objects.
-
-- Using the ``expand`` query parameter, you can chose which fields will be expanded into full objects. For example,
-  if you pass ``expand=voucher`` to the list of order positions, the response will contain a full voucher object
-  instead of just the ID. If you do not have permission to view vouchers, a 403 status code is returned.
-  For performance reasons, this option is only available for a limited number of fields that are noted as
-  "expandable" in the documentation of the respective object.
-
-In all of these, you can use dotted notation to address fields of sub-objects, such as ``positions.checkins.gate``.
-
-These options are not available everywhere as we are slowly rolling them out throughout the codebase. Please check
-the individual endpoint documentation for availability.
 
 Idempotency
 -----------

doc/api/resources/checkin.rst

@@ -359,3 +359,65 @@ Performing a ticket search
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer or check-in list does not exist **or** you have no permission to view this resource.
    :statuscode 404: The requested check-in list does not exist.
+
+.. _`rest-checkin-annul`:
+
+Annulment of a check-in
+-----------------------
+
+.. http:post:: /api/v1/organizers/(organizer)/checkinrpc/annul/
+
+   If a check-in was made in error and the person was not let in, it can be annulled. We do not recommend this to be used
+   in case of manual check-ins or user interfaces because it is too prone for human errors. It is mostly intended for
+   automated entry systems like a turnstile or automated door, where the check-in is first created, then the door is
+   opened, and then the check-in may be annulled if the system knows that the turnstile did not turn or was out of
+   order.
+
+   This endpoint supports passing multiple check-in lists for the context of a multi-event scan. However, each
+   check-in list passed needs to be from a distinct event.
+
+   Check-ins created by a device can only be annulled by the same device. The datetime of annulment may not be more than
+   15 minutes after the datetime of check-in (value subject to change).
+
+   A status code of 404 is returned if no check-in was found for the given nonce. A status code of 400 is returned when
+   multiple check-ins match the nonce, the input is invalid in another way, the annulment is made from the wrong device,
+   the check-in is already in an annulled or failed state, or the datetime constraint is not valid.
+
+   :<json string nonce: ``nonce`` value of the original check-in.
+   :<json array lists: List of check-in list IDs to search on. No two check-in lists may be from the same event.
+   :<json datetime datetime: Specifies the client-side datetime of the annulment. If not supplied, the current time will be used.
+   :<json string error_explanation: A human-readable description of why the check-in was annulled (optional).
+   :>json string status: ``"ok"``
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/checkinrpc/annul/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+      {
+        "lists": [1],
+        "nonce": "Pvrk50vUzQd0DhdpNRL4I4OcXsvg70uA",
+        "error_explanation": "Turnstile did not turn"
+      }
+
+   **Example successful response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "status": "ok",
+      }
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :statuscode 200: no error
+   :statuscode 400: Invalid or incomplete request, see above
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.
+   :statuscode 404: The requested nonce does not exist.

doc/api/resources/events.rst

@@ -152,8 +152,6 @@ Endpoints
                                  and ``null`` for "status unknown". These values might be served from a cache. This parameter can make the response
                                  slow.
    :query search: Only return events matching a given search query.
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
    :param organizer: The ``slug`` field of a valid organizer
    :statuscode 200: no error
    :statuscode 401: Authentication failure
@@ -225,8 +223,6 @@ Endpoints
 
    :param organizer: The ``slug`` field of the organizer to fetch
    :param event: The ``slug`` field of the event to fetch
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
    :statuscode 200: no error
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view it.
@@ -428,9 +424,9 @@ Endpoints
    :param organizer: The ``slug`` field of the organizer of the event to create.
    :param event: The ``slug`` field of the event to copy settings and items from.
    :statuscode 201: no error
-   :statuscode 400: The event could not be created due to invalid submitted data.
+   :statuscode 400: The event could not be updated due to invalid submitted data.
    :statuscode 401: Authentication failure
-   :statuscode 403: The requested organizer does not exist **or** you have no permission to create this resource.
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to update this resource.
 
 
 .. http:patch:: /api/v1/organizers/(organizer)/events/(event)/

doc/api/resources/exhibitors.rst

@@ -349,6 +349,45 @@ Endpoints
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer or event or exhibitor does not exist **or** you have no permission to view it.
 
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/(id)/vouchers/bulk_attach/
+
+   Attaches many **existing** vouchers to an exhibitor. You need to send either the ``id`` **or** the ``code`` field of
+   the voucher, but you need to send the same field for all entries.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/exhibitors/1/vouchers/bulk_attach/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+     [
+       {
+         "id": 15,
+         "exhibitor_comment": "Free ticket"
+       },
+       ..
+     ]
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {}
+
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of the event to use
+   :param id: The ``id`` field of the exhibitor to use
+   :statuscode 200: no error
+   :statuscode 400: Invalid data sent, e.g. voucher does not exist
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer or event or exhibitor does not exist **or** you have no permission to view it.
+
 .. http:post:: /api/v1/organizers/(organizer)/events/(event)/exhibitors/
 
    Create a new exhibitor.

doc/api/resources/index.rst

@@ -25,6 +25,7 @@ at :ref:`plugin-docs`.
    seats
    orders
    invoices
+   transactions
    vouchers
    discounts
    checkin
@@ -54,6 +55,7 @@ at :ref:`plugin-docs`.
    digital
    exhibitors
    imported_secrets
+   offlinesales
    shipping
    billing_invoices
    billing_var

doc/api/resources/invoices.rst

@@ -1,3 +1,5 @@
+.. _rest-invoices:
+
 Invoices
 ========
 
@@ -24,6 +26,8 @@ invoice_from_country                  string                     Sender address:
 invoice_from_tax_id                   string                     Sender address: Local Tax ID
 invoice_from_vat_id                   string                     Sender address: EU VAT ID
 invoice_to                            string                     Full recipient address
+invoice_to_is_business                boolean                    Recipient address: Business vs individual (``null`` for
+                                                                 invoices created before pretix 2025.6).
 invoice_to_company                    string                     Recipient address: Company name
 invoice_to_name                       string                     Recipient address: Person name
 invoice_to_street                     string                     Recipient address: Address lines
@@ -33,6 +37,7 @@ invoice_to_state                      string                     Recipient addre
 invoice_to_country                    string                     Recipient address: Country code
 invoice_to_vat_id                     string                     Recipient address: EU VAT ID
 invoice_to_beneficiary                string                     Invoice beneficiary
+invoice_to_transmission_info          object                     Additional transmission info (see :ref:`rest-transmission-types`)
 custom_field                          string                     Custom invoice address field
 date                                  date                       Invoice date
 refers                                string                     Invoice number of an invoice this invoice refers to
@@ -108,6 +113,12 @@ foreign_currency_rate                 decimal (string)           If ``foreign_cu
 foreign_currency_rate_date            date                       If ``foreign_currency_rate`` is set, this signifies the
                                                                  date at which the currency rate was obtained.
 internal_reference                    string                     Customer's reference to be printed on the invoice.
+transmission_type                     string                     Requested transmission channel (see :ref:`rest-transmission-types`)
+transmission_provider                 string                     Selected transmission provider (depends on installed
+                                                                 plugins). ``null`` if not yet chosen.
+transmission_status                   string                     Transmission status, one of ``unknown`` (pre-2025.6),
+                                                                 ``pending``, ``inflight``, ``failed``, and ``completed``.
+transmission_date                     datetime                   Time of last change in transmission status (may be ``null``).
 ===================================== ========================== =======================================================
 
 
@@ -119,6 +130,76 @@ internal_reference                    string                     Customer's refe
 
    The ``tax_code`` attribute has been added.
 
+.. versionchanged:: 2025.6
+
+   The attributes ``invoice_to_is_business``, ``invoice_to_transmission_info``, ``transmission_type``,
+   ``transmission_provider``, ``transmission_status``, and ``transmission_date`` have been added.
+
+
+.. _`rest-transmission-types`:
+
+Transmission types
+------------------
+
+pretix supports multiple ways to transmit an invoice from the organizer to the invoice recipient.
+For each transmission type, different fields are supported in the ``transmission_info`` object of the
+invoice address. Currently, pretix supports the following transmission types:
+
+Email
+"""""
+
+The identifier ``"email"`` represents the transmission of PDF invoices through email.
+This is the default transmission type in pretix and has some special behavior for backwards compatibility.
+Transmission is always executed through the provider ``"email_pdf"``.
+The ``transmission_info`` object may contain the following properties:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+transmission_email_address            string                     Optional. An email address other than the order address
+                                                                 that the invoice should be sent to.
+                                                                 Business customers only.
+===================================== ========================== =======================================================
+
+Peppol
+""""""
+
+The identifier ``"peppol"`` represents the transmission of XML invoices through the `Peppol`_ network.
+This is only available for business addresses.
+This is not supported by pretix out of the box and requires the use of a suitable plugin.
+The ``transmission_info`` object may contain the following properties:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+transmission_peppol_participant_id    string                     Required. The Peppol participant ID of the recipient.
+===================================== ========================== =======================================================
+
+Italian Exchange System
+"""""""""""""""""""""""
+
+The identifier ``"it_sdi"`` represents the transmission of XML invoices through the `Sistema di Interscambio`_ network used in Italy.
+This is only available for addresses with country ``"IT"``.
+This is not supported by pretix out of the box and requires the use of a suitable plugin.
+The ``transmission_info`` object may contain the following properties:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+transmission_it_sdi_codice_fiscale    string                     Required for non-business address. Fiscal code of the
+                                                                 recipient.
+transmission_it_sdi_pec               string                     Required for business addresses. Address for certified
+                                                                 electronic mail.
+transmission_it_sdi_recipient_code    string                     Required for businesses. SdI recipient code.
+===================================== ========================== =======================================================
+
+If this type is selected, ``vat_id`` is required for business addresses.
 
 List of all invoices
 --------------------
@@ -162,6 +243,7 @@ List of all invoices
             "invoice_from_vat_id":"",
             "invoice_to": "Sample company\nJohn Doe\nTest street 12\n12345 Testington\nTestikistan\nVAT-ID: EU123456789",
             "invoice_to_company": "Sample company",
+            "invoice_to_is_business": true,
             "invoice_to_name": "John Doe",
             "invoice_to_street": "Test street 12",
             "invoice_to_zipcode": "12345",
@@ -170,6 +252,7 @@ List of all invoices
             "invoice_to_country": "TE",
             "invoice_to_vat_id": "EU123456789",
             "invoice_to_beneficiary": "",
+            "invoice_to_transmission_info": {},
             "custom_field": null,
             "date": "2017-12-01",
             "refers": null,
@@ -202,7 +285,11 @@ List of all invoices
             ],
             "foreign_currency_display": "PLN",
             "foreign_currency_rate": "4.2408",
-            "foreign_currency_rate_date": "2017-07-24"
+            "foreign_currency_rate_date": "2017-07-24",
+            "transmission_type": "email",
+            "transmission_provider": "email_pdf",
+            "transmission_status": "completed",
+            "transmission_date": "2017-07-24T10:00:00Z"
           }
         ]
       }
@@ -302,6 +389,7 @@ Fetching individual invoices
         "invoice_from_vat_id":"",
         "invoice_to": "Sample company\nJohn Doe\nTest street 12\n12345 Testington\nTestikistan\nVAT-ID: EU123456789",
         "invoice_to_company": "Sample company",
+        "invoice_to_is_business": true,
         "invoice_to_name": "John Doe",
         "invoice_to_street": "Test street 12",
         "invoice_to_zipcode": "12345",
@@ -310,6 +398,7 @@ Fetching individual invoices
         "invoice_to_country": "TE",
         "invoice_to_vat_id": "EU123456789",
         "invoice_to_beneficiary": "",
+        "invoice_to_transmission_info": {},
         "custom_field": null,
         "date": "2017-12-01",
         "refers": null,
@@ -342,7 +431,11 @@ Fetching individual invoices
         ],
         "foreign_currency_display": "PLN",
         "foreign_currency_rate": "4.2408",
-        "foreign_currency_rate_date": "2017-07-24"
+        "foreign_currency_rate_date": "2017-07-24",
+        "transmission_type": "email",
+        "transmission_provider": "email_pdf",
+        "transmission_status": "completed",
+        "transmission_date": "2017-07-24T10:00:00Z"
       }
 
    :param organizer: The ``slug`` field of the organizer to fetch
@@ -447,3 +540,70 @@ Invoices cannot be edited directly, but the following actions can be triggered:
    :statuscode 400: The invoice has already been canceled
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer/event does not exist **or** you have no permission to change this resource.
+
+
+Transmitting invoices
+---------------------
+
+Invoices are transmitted automatically when created during order creation or payment receipt,
+but in other cases transmission may need to be triggered manually.
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/invoices/(number)/transmit/
+
+   Transmits the invoice to the recipient, but only if it is in ``pending`` state.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/invoices/00001/transmit/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 204 No Content
+      Vary: Accept
+      Content-Type: application/pdf
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :param number: The ``number`` field of the invoice to transmit
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to transmit this invoice **or** the invoice may not be transmitted
+   :statuscode 409: The invoice is currently in transmission
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/invoices/(number)/retransmit/
+
+   Transmits the invoice to the recipient even if transmission was already attempted previously.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/invoices/00001/retransmit/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 204 No Content
+      Vary: Accept
+      Content-Type: application/pdf
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :param number: The ``number`` field of the invoice to transmit
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to transmit this invoice **or** the invoice may not be transmitted
+   :statuscode 409: The invoice is currently in transmission
+
+
+.. _Peppol: https://en.wikipedia.org/wiki/PEPPOL
+.. _Sistema di Interscambio: https://it.wikipedia.org/wiki/Fattura_elettronica_in_Italia

doc/api/resources/items.rst

@@ -19,7 +19,7 @@ name                                    multi-lingual string       The item's vi
 internal_name                           string                     An optional name that is only used in the backend
 default_price                           money (string)             The item price that is applied if the price is not
                                                                    overwritten by variations or other options.
-category                                integer (expandable)       The ID of the category this item belongs to
+category                                integer                    The ID of the category this item belongs to
                                                                    (or ``null``).
 active                                  boolean                    If ``false``, the item is hidden from all public lists
                                                                    and will not be sold.
@@ -33,7 +33,7 @@ free_price_suggestion                   money (string)             A suggested p
                                                                    ``free_price`` is set (or ``null``).
 tax_rate                                decimal (string)           The VAT rate to be applied for this item (read-only,
                                                                    set through ``tax_rule``).
-tax_rule                                integer (expandable)       The internal ID of the applied tax rule (or ``null``).
+tax_rule                                integer                    The internal ID of the applied tax rule (or ``null``).
 admission                               boolean                    ``true`` for items that grant admission to the event
                                                                    (such as primary tickets) and ``false`` for others
                                                                    (such as add-ons or merchandise).
@@ -390,9 +390,6 @@ Endpoints
                               will be returned.
    :query string ordering: Manually set the ordering of results. Valid fields to be used are ``id`` and ``position``.
                            Default: ``position``
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
-   :query string expand: Expand an object reference with the referenced object. Can be passed multiple times.
    :param organizer: The ``slug`` field of the organizer to fetch
    :param event: The ``slug`` field of the event to fetch
    :statuscode 200: no error
@@ -534,9 +531,6 @@ Endpoints
    :param organizer: The ``slug`` field of the organizer to fetch
    :param event: The ``slug`` field of the event to fetch
    :param id: The ``id`` field of the item to fetch
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
-   :query string expand: Expand an object reference with the referenced object. Can be passed multiple times.
    :statuscode 200: no error
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.

doc/api/resources/offlinesales.rst

@@ -0,0 +1,219 @@
+Offline sales
+=============
+
+.. note:: This API is only available when the plugin **pretix-offlinesales** is installed (pretix Hosted and Enterprise only).
+
+The offline sales module allows you to create batches of tickets intended for the sale outside the system.
+
+Resource description
+--------------------
+
+The offline sales batch resource contains the following public fields:
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+id                                    integer                    Internal batch ID
+creation                              datetime                   Time of creation
+testmode                              boolean                    ``true`` if orders are created in test mode
+sales_channel                         string                     Sales channel of the orders
+layout                                integer                    Internal ID of the chosen ticket layout
+subevent                              integer                    Internal ID of the chosen subevent (or ``null``)
+item                                  integer                    Internal ID of the chosen product
+variation                             integer                    Internal ID of the chosen variation (or ``null``)
+amount                                integer                    Number of tickets in the batch
+comment                               string                     Internal comment
+orders                                list of strings            List of order codes (omitted in list view for performance reasons)
+===================================== ========================== =======================================================
+
+Endpoints
+---------
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/offlinesalesbatches/
+
+   Returns a list of all offline sales batches
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/democon/offlinesalesbatches/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: text/javascript
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "id": 1,
+            "creation": "2025-07-08T18:27:32.134368+02:00",
+            "testmode": False,
+            "sales_channel": "web",
+            "comment": "Batch for sale at the event",
+            "layout": 3,
+            "subevent": null,
+            "item": 23,
+            "variation": null,
+            "amount": 7
+          }
+        ]
+      }
+
+   :query page: The page number in case of a multi-page result set, default is 1
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of a valid event
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/offlinesalesbatches/(id)/
+
+   Returns information on a given batch.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/democon/offlinesalesbatches/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: text/javascript
+
+      {
+        "id": 1,
+        "creation": "2025-07-08T18:27:32.134368+02:00",
+        "testmode": False,
+        "sales_channel": "web",
+        "comment": "Batch for sale at the event",
+        "layout": 3,
+        "subevent": null,
+        "item": 23,
+        "variation": null,
+        "amount": 7,
+        "orders": ["TSRNN", "3FBSL", "WMDNJ", "BHW9H", "MXSUG", "DSDAP", "URLLE"]
+      }
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :param id: The ``id`` field of the batch to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view it.
+
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/offlinesalesbatches/
+
+   With this API call, you can instruct the system to create a new batch.
+
+   Since batches can contain up to 10,000 tickets, they are created asynchronously on the server.
+   If your input parameters validate correctly, a ``202 Accepted`` status code is returned.
+   The body points you to the check URL of the result. Running a ``GET`` request on that result URL will
+   yield one of the following status codes:
+
+    * ``200 OK`` – The creation of the batch has succeeded. The body will be your resulting batch with the same information as in the detail endpoint above.
+    * ``409 Conflict`` – Your creation job is still running. The body will be JSON with the structure ``{"status": "running"}``. ``status`` can be ``waiting`` before the task is actually being processed. Please retry, but wait at least one second before you do.
+    * ``410 Gone`` – Creating the batch has failed permanently (e.g. quota no longer available). The body will be JSON with the structure ``{"status": "failed", "message": "Error message"}``
+    * ``404 Not Found`` – The job does not exist / is expired.
+
+   .. note:: To avoid performance issues, a maximum amount of 10000 is currently allowed.
+
+   .. note:: Do not wait multiple hours or more to retrieve your result. After a longer wait time, ``409`` might be returned permanently due to technical constraints, even though nothing will happen any more.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/offlinesalesbatches/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+
+      {
+        "testmode": True,
+        "layout": 123,
+        "item": 14,
+        "sales_channel": "web",
+        "amount": 10,
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "check": "https://pretix.eu/api/v1/organizers/bigevents/events/sampleconf/offlinesalesbatches/check/29891ede-196f-4942-9e26-d055a36e98b8/"
+      }
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :statuscode 202: no error
+   :statuscode 400: Invalid input options
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.
+
+
+.. http:post:: /api/v1/organizers/(organizer)/events/(event)/offlinesalesbatches/(id)/render/
+
+   With this API call, you can render the PDF representation of a batch.
+
+   Since batches can contain up to 10,000 tickets, they are rendered asynchronously on the server.
+   If your input parameters validate correctly, a ``202 Accepted`` status code is returned.
+   The body points you to the download URL of the result. Running a ``GET`` request on that result URL will
+   yield one of the following status codes:
+
+    * ``200 OK`` – The creation of the batch has succeeded. The body will be your resulting batch with the same information as in the detail endpoint above.
+    * ``409 Conflict`` – Your rendering process is still running. The body will be JSON with the structure ``{"status": "running"}``. ``status`` can be ``waiting`` before the task is actually being processed. Please retry, but wait at least one second before you do.
+    * ``410 Gone`` – Rendering the batch has failed permanently. The body will be JSON with the structure ``{"status": "failed", "message": "Error message"}``
+    * ``404 Not Found`` – The rendering job does not exist / is expired.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      POST /api/v1/organizers/bigevents/events/sampleconf/offlinesalesbatches/1/render HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "download": "https://pretix.eu/api/v1/organizers/bigevents/events/sampleconf/offlinesalesbatches/1/download/29891ede-196f-4942-9e26-d055a36e98b8/3f279f13-c198-4137-b49b-9b360ce9fcce/"
+      }
+
+   :param organizer: The ``slug`` field of the organizer to fetch
+   :param event: The ``slug`` field of the event to fetch
+   :param id: The ``id`` field of the batch to fetch
+   :statuscode 202: no error
+   :statuscode 400: Invalid input options
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view this resource.
+

doc/api/resources/orders.rst

@@ -65,11 +65,16 @@ invoice_address                       object                     Invoice address
 ├ state                               string                     Customer state (ISO 3166-2 code). Only supported in
                                                                  AU, BR, CA, CN, MY, MX, and US.
 ├ internal_reference                  string                     Customer's internal reference to be printed on the invoice
+
 ├ custom_field                        string                     Custom invoice address field
 ├ vat_id                              string                     Customer VAT ID
-└ vat_id_validated                    string                     ``true``, if the VAT ID has been validated against the
+├ vat_id_validated                    string                     ``true``, if the VAT ID has been validated against the
                                                                  EU VAT service and validation was successful. This only
                                                                  happens in rare cases.
+├ transmission_type                   string                     Transmission channel for invoice (see also :ref:`rest-transmission-types`).
+                                                                 Defaults to ``email``.
+└ transmission_info                   object                     Transmission-channel specific information (or ``null``).
+                                                                 See also :ref:`rest-transmission-types`.
 positions                             list of objects            List of order positions (see below). By default, only
                                                                  non-canceled positions are included.
 fees                                  list of objects            List of fees included in the order total. By default, only
@@ -142,6 +147,10 @@ plugin_data                           object                     Additional data
 
    The ``plugin_data`` attribute has been added.
 
+.. versionchanged:: 2025.6
+
+   The ``invoice_address.transmission_type`` and ``invoice_address.transmission_info`` attributes have been added.
+
 .. _order-position-resource:
 
 Order position resource
@@ -157,8 +166,8 @@ order                                 string                     Order code of t
 positionid                            integer                    Number of the position within the order
 canceled                              boolean                    Whether or not this position has been canceled. Note that
                                                                  by default, only non-canceled positions are shown.
-item                                  integer (expandable)       ID of the purchased item
-variation                             integer (expandable)       ID of the purchased variation (or ``null``)
+item                                  integer                    ID of the purchased item
+variation                             integer                    ID of the purchased variation (or ``null``)
 price                                 money (string)             Price of this position
 attendee_name                         string                     Specified attendee name for this position (or ``null``)
 attendee_name_parts                   object of strings          Decomposition of attendee name (i.e. given name, family name)
@@ -170,7 +179,7 @@ city                                  string                     Attendee city (
 country                               string                     Attendee country code (or ``null``)
 state                                 string                     Attendee state (ISO 3166-2 code). Only supported in
                                                                  AU, BR, CA, CN, MY, MX, and US, otherwise ``null``.
-voucher                               integer (expandable)       Internal ID of the voucher used for this position (or ``null``)
+voucher                               integer                    Internal ID of the voucher used for this position (or ``null``)
 voucher_budget_use                    money (string)             Amount of money discounted by the voucher, corresponding
                                                                  to how much of the ``budget`` of the voucher is consumed.
                                                                  **Important:** Do not rely on this amount to be a useful
@@ -182,7 +191,7 @@ tax_code                              string                     Codified reason
 tax_rule                              integer                    The ID of the used tax rule (or ``null``)
 secret                                string                     Secret code printed on the tickets for validation
 addon_to                              integer                    Internal ID of the position this position is an add-on for (or ``null``)
-subevent                              integer (expandable)       ID of the date inside an event series this position belongs to (or ``null``).
+subevent                              integer                    ID of the date inside an event series this position belongs to (or ``null``).
 discount                              integer                    ID of a discount that has been used during the creation of this position in some way (or ``null``).
 blocked                               list of strings            A list of strings, or ``null``. Whenever not ``null``, the ticket may not be used (e.g. for check-in).
 valid_from                            datetime                   The ticket will not be valid before this time. Can be ``null``.
@@ -368,7 +377,9 @@ List of all orders
                 "state": "",
                 "internal_reference": "",
                 "vat_id": "EU123456789",
-                "vat_id_validated": false
+                "vat_id_validated": false,
+                "transmission_type": "email",
+                "transmission_info": {}
             },
             "positions": [
               {
@@ -407,6 +418,7 @@ List of all orders
                 "seat": null,
                 "checkins": [
                   {
+                    "id": 1337,
                     "list": 44,
                     "type": "entry",
                     "gate": null,
@@ -610,7 +622,9 @@ Fetching individual orders
             "state": "",
             "internal_reference": "",
             "vat_id": "EU123456789",
-            "vat_id_validated": false
+            "vat_id_validated": false,
+            "transmission_type": "email",
+            "transmission_info": {}
         },
         "positions": [
           {
@@ -649,6 +663,7 @@ Fetching individual orders
             "seat": null,
             "checkins": [
               {
+                "id": 1337,
                 "list": 44,
                 "type": "entry",
                 "gate": null,
@@ -1017,6 +1032,8 @@ Creating orders
       * ``vat_id_validated`` (optional) – If you need support for reverse charge (rarely the case), you need to check
          yourself if the passed VAT ID is a valid EU VAT ID. In that case, set this to ``true``. Only valid VAT IDs will
          trigger reverse charge taxation. Don't forget to set ``is_business`` as well!
+     * ``transmission_type`` (optional, defaults to ``email``)
+     * ``transmission_info`` (optional, see also :ref:`rest-transmission-types`)
 
    * ``positions``
 
@@ -1617,6 +1634,7 @@ List of all order positions
             "blocked": null,
             "checkins": [
               {
+                "id": 1337,
                 "list": 44,
                 "type": "entry",
                 "gate": null,
@@ -1745,6 +1763,7 @@ Fetching individual positions
         "seat": null,
         "checkins": [
           {
+            "id": 1337,
             "list": 44,
             "type": "entry",
             "gate": null,
@@ -1926,6 +1945,7 @@ Manipulating individual positions
 
       (Full order position resource, see above.)
 
+   :query boolean check_quotas: Whether to check quotas before committing item changes, default is ``true``
    :param organizer: The ``slug`` field of the organizer of the event
    :param event: The ``slug`` field of the event
    :param id: The ``id`` field of the order position to update
@@ -2005,6 +2025,7 @@ Manipulating individual positions
 
       (Full order position resource, see above.)
 
+   :query boolean check_quotas: Whether to check quotas before creating the new position, default is ``true``
    :param organizer: The ``slug`` field of the organizer of the event
    :param event: The ``slug`` field of the event
 
@@ -2291,6 +2312,7 @@ otherwise, such as splitting an order or changing fees.
 
       (Full order position resource, see above.)
 
+   :query boolean check_quotas: Whether to check quotas before patching or creating positions, default is ``true``
    :param organizer: The ``slug`` field of the organizer of the event
    :param event: The ``slug`` field of the event
    :param code: The ``code`` field of the order to update

doc/api/resources/organizers.rst

@@ -19,6 +19,11 @@ name                                  string                     The organizer's
 slug                                  string                     A short form of the name, used e.g. in URLs.
 public_url                            string                     The public, customer-facing URL of the organizer, where
                                                                  the list of all events can be found (read-only).
+plugins                               list                       A list of package names of the enabled plugins for this
+                                                                 organizer. Note that most plugins are enabled on the
+                                                                 event level (or both levels). If you remove a plugin
+                                                                 that is also enabled on some events, it will
+                                                                 automatically be removed from all events as well.
 ===================================== ========================== =======================================================
 
 
@@ -53,7 +58,10 @@ Endpoints
           {
             "name": "Big Events LLC",
             "slug": "Big Events",
-            "public_url": "https://pretix.eu/bigevents/"
+            "public_url": "https://pretix.eu/bigevents/",
+            "plugins": [
+              "pretix_datev"
+            ]
           }
         ]
       }
@@ -61,8 +69,6 @@ Endpoints
    :query page: The page number in case of a multi-page result set, default is 1
    :query string ordering: Manually set the ordering of results. Valid fields to be used are ``slug`` and
                            ``name``. Default: ``slug``.
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
    :statuscode 200: no error
    :statuscode 401: Authentication failure
 
@@ -89,16 +95,61 @@ Endpoints
       {
         "name": "Big Events LLC",
         "slug": "Big Events",
-        "public_url": "https://pretix.eu/bigevents/"
+        "public_url": "https://pretix.eu/bigevents/",
+        "plugins": [
+          "pretix_datev"
+        ]
       }
 
    :param organizer: The ``slug`` field of the organizer to fetch
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
    :statuscode 200: no error
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
 
+.. http:patch:: /api/v1/organizers/(organizer)/
+
+   Updates an organizer. Currently only the ``plugins`` field may be updated.
+
+   Permission required: "Can change organizer settings"
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      PATCH /api/v1/organizers/bigevents/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+      Content-Type: application/json
+
+      {
+        "plugins": [
+          "pretix_seating"
+        ]
+      }
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "name": "Big Events LLC",
+        "slug": "Big Events",
+        "public_url": "https://pretix.eu/bigevents/",
+        "plugins": [
+          "pretix_seating"
+        ]
+      }
+
+   :param organizer: The ``slug`` field of the organizer to update
+   :statuscode 200: no error
+   :statuscode 400: The organizer could not be updated due to invalid submitted data.
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to update this resource.
+
 Organizer settings
 ------------------
 

doc/api/resources/quotas.rst

@@ -28,6 +28,8 @@ closed                                boolean                    Whether the quo
                                                                  field).
 release_after_exit                    boolean                    Whether the quota regains capacity as soon as some tickets
                                                                  have been scanned at an exit.
+ignore_for_event_availability         boolean                    Whether the quota is ignored when calculating the event's
+                                                                 availability of tickets.
 available                             boolean                    Whether this quota is available. Only returned if ``with_availability=true``
                                                                  is set on the request. Do not rely on this value for critical operations, it may be
                                                                  slightly out of date.
@@ -36,6 +38,10 @@ available_number                      integer                    Number of avail
                                                                  slightly out of date. ``null`` means unlimited.
 ===================================== ========================== =======================================================
 
+.. versionchanged:: 2025.7
+
+    The attribute ``ignore_for_event_availability`` has been added.
+
 Endpoints
 ---------
 
@@ -72,7 +78,8 @@ Endpoints
             "variations": [1, 4, 5, 7],
             "subevent": null,
             "close_when_sold_out": false,
-            "closed": false
+            "closed": false,
+            "ignore_for_event_availability": false
           }
         ]
       }
@@ -118,7 +125,8 @@ Endpoints
         "variations": [1, 4, 5, 7],
         "subevent": null,
         "close_when_sold_out": false,
-        "closed": false
+        "closed": false,
+        "ignore_for_event_availability": false
       }
 
    :param organizer: The ``slug`` field of the organizer to fetch
@@ -149,7 +157,8 @@ Endpoints
         "variations": [1, 4, 5, 7],
         "subevent": null,
         "close_when_sold_out": false,
-        "closed": false
+        "closed": false,
+        "ignore_for_event_availability": false
       }
 
    **Example response**:
@@ -168,7 +177,8 @@ Endpoints
         "variations": [1, 4, 5, 7],
         "subevent": null,
         "close_when_sold_out": false,
-        "closed": false
+        "closed": false,
+        "ignore_for_event_availability": false
       }
 
    :param organizer: The ``slug`` field of the organizer of the event/item to create a quota for
@@ -223,7 +233,8 @@ Endpoints
         ],
         "subevent": null,
         "close_when_sold_out": false,
-        "closed": false
+        "closed": false,
+        "ignore_for_event_availability": false
       }
 
    :param organizer: The ``slug`` field of the organizer to modify

doc/api/resources/subevents.rst

@@ -146,70 +146,10 @@ Endpoints
                                  attribute with values of 100 for "tickets available", values less than 100 for "tickets sold out or reserved",
                                  and ``null`` for "status unknown". These values might be served from a cache. This parameter can make the response
                                  slow.
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
    :statuscode 200: no error
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.
 
-.. http:get:: /api/v1/organizers/(organizer)/events/(event)/subevents/(id)/
-
-   Returns information on one sub-event, identified by its ID.
-
-   **Example request**:
-
-   .. sourcecode:: http
-
-      GET /api/v1/organizers/bigevents/events/sampleconf/subevents/1/ HTTP/1.1
-      Host: pretix.eu
-      Accept: application/json, text/javascript
-
-   **Example response**:
-
-   .. sourcecode:: http
-
-      HTTP/1.1 200 OK
-      Vary: Accept
-      Content-Type: application/json
-
-      {
-        "id": 1,
-        "name": {"en": "First Sample Conference"},
-        "event": "sampleconf",
-        "active": false,
-        "is_public": true,
-        "date_from": "2017-12-27T10:00:00Z",
-        "date_to": null,
-        "date_admission": null,
-        "presale_start": null,
-        "presale_end": null,
-        "location": null,
-        "geo_lat": null,
-        "geo_lon": null,
-        "seating_plan": null,
-        "seat_category_mapping": {},
-        "item_price_overrides": [
-          {
-            "item": 2,
-            "disabled": false,
-            "available_from": null,
-            "available_until": null,
-            "price": "12.00"
-          }
-        ],
-        "variation_price_overrides": [],
-        "meta_data": {}
-      }
-
-   :param organizer: The ``slug`` field of a valid organizer
-   :param event: The ``slug`` field of the main event
-   :param id: The ``id`` field of the sub-event to fetch
-   :query string include: Limit the output to the given field. Can be passed multiple times.
-   :query string exclude: Exclude a field from the output. Can be passed multiple times.
-   :statuscode 200: no error
-   :statuscode 401: Authentication failure
-   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view it.
-
 .. http:post:: /api/v1/organizers/(organizer)/events/(event)/subevents/
 
    Creates a new subevent.
@@ -297,6 +237,63 @@ Endpoints
    :statuscode 401: Authentication failure
    :statuscode 403: The requested organizer does not exist **or** you have no permission to create this resource.
 
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/subevents/(id)/
+
+   Returns information on one sub-event, identified by its ID.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/subevents/1/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "id": 1,
+        "name": {"en": "First Sample Conference"},
+        "event": "sampleconf",
+        "active": false,
+        "is_public": true,
+        "date_from": "2017-12-27T10:00:00Z",
+        "date_to": null,
+        "date_admission": null,
+        "presale_start": null,
+        "presale_end": null,
+        "location": null,
+        "geo_lat": null,
+        "geo_lon": null,
+        "seating_plan": null,
+        "seat_category_mapping": {},
+        "item_price_overrides": [
+          {
+            "item": 2,
+            "disabled": false,
+            "available_from": null,
+            "available_until": null,
+            "price": "12.00"
+          }
+        ],
+        "variation_price_overrides": [],
+        "meta_data": {}
+      }
+
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of the main event
+   :param id: The ``id`` field of the sub-event to fetch
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer/event does not exist **or** you have no permission to view it.
+
 .. http:patch:: /api/v1/organizers/(organizer)/events/(event)/subevents/(id)/
 
    Updates a sub-event, identified by its ID. You can also use ``PUT`` instead of ``PATCH``. With ``PUT``, you have to

doc/api/resources/taxrules.rst

@@ -26,6 +26,8 @@ rate                                  decimal (string)           Tax rate in per
 code                                  string                     Codified reason for tax rate (or ``null``), see :ref:`rest-taxcodes`.
 price_includes_tax                    boolean                    If ``true`` (default), tax is assumed to be included in
                                                                  the specified product price
+default                               boolean                    If ``true`` (default), this is the default tax rate for this event
+                                                                 (there can only be one per event).
 eu_reverse_charge                     boolean                    **DEPRECATED**. If ``true``, EU reverse charge rules
                                                                  are applied. Will be ignored if custom rules are set.
                                                                  Use custom rules instead.
@@ -48,6 +50,10 @@ custom_rules                          object                     Dynamic rules s
 
     The ``code`` attribute has been added.
 
+.. versionchanged:: 2025.4
+
+    The ``default`` attribute has been added.
+
 .. _rest-taxcodes:
 
 Tax codes
@@ -111,6 +117,7 @@ Endpoints
           {
             "id": 1,
             "name": {"en": "VAT"},
+            "default": true,
             "internal_name": "VAT",
             "code": "S/standard",
             "rate": "19.00",
@@ -153,6 +160,7 @@ Endpoints
       {
         "id": 1,
         "name": {"en": "VAT"},
+            "default": true,
         "internal_name": "VAT",
         "code": "S/standard",
         "rate": "19.00",
@@ -203,6 +211,7 @@ Endpoints
       {
         "id": 1,
         "name": {"en": "VAT"},
+        "default": false,
         "internal_name": "VAT",
         "code": "S/standard",
         "rate": "19.00",

doc/api/resources/transactions.rst

@@ -0,0 +1,232 @@
+.. _rest-transactions:
+
+Transactions
+============
+
+Transactions are an additional way to think about orders. They are are an immutable, filterable view into an order's
+history and are a good basis for financial reporting.
+
+Our financial model
+-------------------
+
+You can think of a pretix order similar to a debtor account in double-entry bookkeeping. For example, the flow of an
+order could look like this:
+
+===================================================== ==================== =====================
+Transaction                                           Debit                Credit
+===================================================== ==================== =====================
+Order is placed with two tickets                      € 500
+Order is paid partially with a gift card                                   € 200
+Remainder is paid with a credit card                                       € 300
+One of the tickets is canceled                        **-** € 250
+Refund is made to the credit card                                          **-** € 250
+**Balance**                                           **€ 250**            **€ 250**
+===================================================== ==================== =====================
+
+If an order is fully settled, the sums of both columns match. However, as the movements in both columns do not always
+happen at the same time, at some times during the lifecycle of an order the sums are not balanced, in which case we
+consider an order to be "pending payment" or "overpaid".
+
+In the API, the "Debit" column is represented by the "transaction" resource listed on this page.
+In many cases, the left column *usually* also matches the data returned by the :ref:`rest-invoices` resource, but there
+are two important differences:
+
+- pretix may be configured such that an invoice is not always generated for an order. In this case, only the transactions
+  return the full data set.
+
+- pretix does not enforce a new invoice to be created e.g. when a ticket is changed to a different subevent. However,
+  pretix always creates a new transaction whenever there is a change to a ticket that concerns the **price**, **tax rate**,
+  **product**, or **date** (in an event series).
+
+The :ref:`rest-orders` themselves are not a good representation of the "Debit" side of the table for accounting
+purposes since they are not immutable:
+They will only tell you the current state of the order, not what it was a week ago.
+
+The "Credit" column is represented by the :ref:`order-payment-resource` and :ref:`order-refund-resource`.
+
+
+Resource description
+--------------------
+
+.. rst-class:: rest-resource-table
+
+===================================== ========================== =======================================================
+Field                                 Type                       Description
+===================================== ========================== =======================================================
+id                                    integer                    Internal ID of the transaction
+order                                 string                     Order code the transaction was created from
+event                                 string                     Event slug, only present on organizer-level API calls
+created                               datetime                   The creation time of the transaction in the database
+datetime                              datetime                   The time at which the transaction is financially relevant.
+                                                                 This is usually the same as created, but may vary for
+                                                                 retroactively created transactions after software bugs or
+                                                                 for data that preceeds this data model.
+positionid                            integer                    Number of the position within the order this refers to,
+                                                                 is ``null`` for transactions that refer to a fee
+count                                 integer                    Number of items purchased, is negative for cancellations
+item                                  integer                    The internal ID of the item purchased (or ``null`` for fees)
+variation                             integer                    The internal ID of the variation purchased (or ``null``)
+subevent                              integer                    The internal ID of the event series date (or ``null``)
+price                                 money (string)             Gross price of the transaction
+tax_rate                              decimal (string)           Tax rate applied in transaction
+tax_rule                              integer                    The internal ID of the tax rule used (or ``null``)
+tax_code                              string                     The selected tax code (or ``null``)
+tax_value                             money (string)             The computed tax value
+fee_type                              string                     The type of fee (or ``null`` for products)
+internal_type                         string                     Additional type classification of the fee (or ``null`` for products)
+===================================== ========================== =======================================================
+
+.. versionchanged:: 2025.7.0
+
+   This resource was added to the API.
+
+
+Endpoints
+---------
+
+.. http:get:: /api/v1/organizers/(organizer)/events/(event)/transactions/
+
+   Returns a list of all transactions of an event.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/events/sampleconf/transactions/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "id": 123,
+            "order": "FOO",
+            "count": 1,
+            "created": "2017-12-01T10:00:00Z",
+            "datetime": "2017-12-01T10:00:00Z",
+            "item": null,
+            "variation": null,
+            "positionid": 1,
+            "price": "23.00",
+            "subevent": null,
+            "tax_code": "E",
+            "tax_rate": "0.00",
+            "tax_rule": 23,
+            "tax_value": "0.00",
+            "fee_type": null,
+            "internal_type": null
+          }
+        ]
+      }
+
+   :query integer page: The page number in case of a multi-page result set, default is 1
+   :query string order: Only return transactions matching the given order code.
+   :query datetime_since: Only return transactions with a datetime at or after the given time.
+   :query datetime_before: Only return transactions with a datetime before the given time.
+   :query created_since: Only return transactions with a creation time at or after the given time.
+   :query created_before: Only return transactions with a creation time before the given time.
+   :query item: Only return transactions that match the given item ID.
+   :query item__in: Only return transactions that match one of the given item IDs (separated with a comma).
+   :query variation: Only return transactions that match the given variation ID.
+   :query variation__in: Only return transactions that match one of the given variation IDs (separated with a comma).
+   :query subevent: Only return transactions that match the given subevent ID.
+   :query subevent__in: Only return transactions that match one of the given subevent IDs (separated with a comma).
+   :query tax_rule: Only return transactions that match the given tax rule ID.
+   :query tax_rule__in: Only return transactions that match one of the given tax rule IDs (separated with a comma).
+   :query tax_code: Only return transactions that match the given tax code.
+   :query tax_code__in: Only return transactions that match one of the given tax codes (separated with a comma).
+   :query tax_rate: Only return transactions that match the given tax rate.
+   :query tax_rate__in: Only return transactions that match one of the given tax rates (separated with a comma).
+   :query fee_type: Only return transactions that match the given fee type.
+   :query fee_type__in: Only return transactions that match one of the given fee types (separated with a comma).
+   :query string ordering: Manually set the ordering of results. Valid fields to be used are ``datetime``, ``created``, and ``id``.
+   :param organizer: The ``slug`` field of a valid organizer
+   :param event: The ``slug`` field of a valid event
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer or event does not exist **or** you have no permission to view it.
+
+.. http:get:: /api/v1/organizers/(organizer)/transactions/
+
+   Returns a list of all transactions of an organizer that you have access to.
+
+   **Example request**:
+
+   .. sourcecode:: http
+
+      GET /api/v1/organizers/bigevents/transactions/ HTTP/1.1
+      Host: pretix.eu
+      Accept: application/json, text/javascript
+
+   **Example response**:
+
+   .. sourcecode:: http
+
+      HTTP/1.1 200 OK
+      Vary: Accept
+      Content-Type: application/json
+
+      {
+        "count": 1,
+        "next": null,
+        "previous": null,
+        "results": [
+          {
+            "id": 123,
+            "event": "sampleconf",
+            "order": "FOO",
+            "count": 1,
+            "created": "2017-12-01T10:00:00Z",
+            "datetime": "2017-12-01T10:00:00Z",
+            "item": null,
+            "variation": null,
+            "positionid": 1,
+            "price": "23.00",
+            "subevent": null,
+            "tax_code": "E",
+            "tax_rate": "0.00",
+            "tax_rule": 23,
+            "tax_value": "0.00",
+            "fee_type": null,
+            "internal_type": null
+          }
+        ]
+      }
+
+   :query integer page: The page number in case of a multi-page result set, default is 1
+   :query string event: Only return transactions matching the given event slug.
+   :query string order: Only return transactions matching the given order code.
+   :query datetime_since: Only return transactions with a datetime at or after the given time.
+   :query datetime_before: Only return transactions with a datetime before the given time.
+   :query created_since: Only return transactions with a creation time at or after the given time.
+   :query created_before: Only return transactions with a creation time before the given time.
+   :query item: Only return transactions that match the given item ID.
+   :query item__in: Only return transactions that match one of the given item IDs (separated with a comma).
+   :query variation: Only return transactions that match the given variation ID.
+   :query variation__in: Only return transactions that match one of the given variation IDs (separated with a comma).
+   :query subevent: Only return transactions that match the given subevent ID.
+   :query subevent__in: Only return transactions that match one of the given subevent IDs (separated with a comma).
+   :query tax_rule: Only return transactions that match the given tax rule ID.
+   :query tax_rule__in: Only return transactions that match one of the given tax rule IDs (separated with a comma).
+   :query tax_code: Only return transactions that match the given tax code.
+   :query tax_code__in: Only return transactions that match one of the given tax codes (separated with a comma).
+   :query tax_rate: Only return transactions that match the given tax rate.
+   :query tax_rate__in: Only return transactions that match one of the given tax rates (separated with a comma).
+   :query fee_type: Only return transactions that match the given fee type.
+   :query fee_type__in: Only return transactions that match one of the given fee types (separated with a comma).
+   :query string ordering: Manually set the ordering of results. Valid fields to be used are ``datetime``, ``created``, and ``id``.
+   :param organizer: The ``slug`` field of a valid organizer
+   :statuscode 200: no error
+   :statuscode 401: Authentication failure
+   :statuscode 403: The requested organizer does not exist **or** you have no permission to view it.

doc/api/resources/vouchers.rst

@@ -14,6 +14,7 @@ The voucher resource contains the following public fields:
 Field                                 Type                       Description
 ===================================== ========================== =======================================================
 id                                    integer                    Internal ID of the voucher
+created                               datetime                   The creation date of the voucher. For vouchers created before pretix 2025.7.0, this is guessed retroactively and might not be accurate.
 code                                  string                     The voucher code that is required to redeem the voucher
 max_usages                            integer                    The maximum number of times this voucher can be
                                                                  redeemed (default: 1).
@@ -49,8 +50,14 @@ subevent                              integer                    ID of the date
 show_hidden_items                     boolean                    Only if set to ``true``, this voucher allows to buy products with the property ``hide_without_voucher``. Defaults to ``true``.
 all_addons_included                   boolean                    If set to ``true``, all add-on products for the product purchased with this voucher are included in the base price.
 all_bundles_included                  boolean                    If set to ``true``, all bundled products for the product purchased with this voucher are added without their designated price.
+budget                                money (string)             The budget a voucher is allowed to consume before being used up (or ``null``)
+budget_used                           money (string)             The amount of budget the voucher has already used up.
 ===================================== ========================== =======================================================
 
+.. versionchanged:: 2025.7
+
+    The attributes ``created``, ``budget``, and ``budget_used`` have been added.
+
 
 Endpoints
 ---------
@@ -82,6 +89,7 @@ Endpoints
         "results": [
           {
             "id": 1,
+            "created": "2020-09-18T14:17:40.971519Z",
             "code": "43K6LKM37FBVR2YG",
             "max_usages": 1,
             "redeemed": 0,
@@ -99,7 +107,9 @@ Endpoints
             "subevent": null,
             "show_hidden_items": false,
             "all_addons_included": false,
-            "all_bundles_included": false
+            "all_bundles_included": false,
+            "budget": None,
+            "budget_used": "0.00"
           }
         ]
       }
@@ -152,6 +162,7 @@ Endpoints
 
       {
         "id": 1,
+        "created": "2020-09-18T14:17:40.971519Z",
         "code": "43K6LKM37FBVR2YG",
         "max_usages": 1,
         "redeemed": 0,
@@ -169,7 +180,9 @@ Endpoints
         "subevent": null,
         "show_hidden_items": false,
         "all_addons_included": false,
-        "all_bundles_included": false
+        "all_bundles_included": false,
+        "budget": None,
+        "budget_used": "0.00"
       }
 
    :param organizer: The ``slug`` field of the organizer to fetch
@@ -222,6 +235,7 @@ Endpoints
 
       {
         "id": 1,
+        "created": "2020-09-18T14:17:40.971519Z",
         "code": "43K6LKM37FBVR2YG",
         "max_usages": 1,
         "redeemed": 0,
@@ -239,7 +253,9 @@ Endpoints
         "subevent": null,
         "show_hidden_items": false,
         "all_addons_included": false,
-        "all_bundles_included": false
+        "all_bundles_included": false,
+        "budget": None,
+        "budget_used": "0.00"
       }
 
    :param organizer: The ``slug`` field of the organizer to create a voucher for
@@ -313,6 +329,7 @@ Endpoints
       [
         {
           "id": 1,
+          "created": "2020-09-18T14:17:40.971519Z",
           "code": "43K6LKM37FBVR2YG",
           …
         }, …
@@ -359,6 +376,7 @@ Endpoints
 
       {
         "id": 1,
+        "created": "2020-09-18T14:17:40.971519Z",
         "code": "43K6LKM37FBVR2YG",
         "max_usages": 1,
         "redeemed": 0,
@@ -376,7 +394,9 @@ Endpoints
         "subevent": null,
         "show_hidden_items": false,
         "all_addons_included": false,
-        "all_bundles_included": false
+        "all_bundles_included": false,
+        "budget": None,
+        "budget_used": "0.00"
       }
 
    :param organizer: The ``slug`` field of the organizer to modify

doc/api/resources/webhooks.rst

@@ -60,6 +60,9 @@ The following values for ``action_types`` are valid with pretix core:
     * ``pretix.event.added``
     * ``pretix.event.changed``
     * ``pretix.event.deleted``
+    * ``pretix.voucher.added``
+    * ``pretix.voucher.changed``
+    * ``pretix.voucher.deleted``
     * ``pretix.subevent.added``
     * ``pretix.subevent.changed``
     * ``pretix.subevent.deleted``

doc/development/api/datasync.rst

@@ -0,0 +1,207 @@
+.. highlight:: python
+   :linenothreshold: 5
+
+Data sync providers
+===================
+
+.. warning:: This feature is considered **experimental**. It might change at any time without prior notice.
+
+pretix provides connectivity to many external services through plugins. A common requirement
+is unidirectionally sending (order, customer, ticket, ...) data into external systems.
+The transfer is usually triggered by signals provided by pretix core (e.g. :data:`order_placed`),
+but performed asynchronously.
+
+Such plugins should use the :class:`OutboundSyncProvider` API to utilize the queueing, retry and mapping 
+mechanisms as well as the user interface for configuration and monitoring. Sync providers are registered 
+in the :py:attr:`pretix.base.datasync.datasync.datasync_providers` :ref:`registry <registries>`.
+
+An :class:`OutboundSyncProvider` for subscribing event participants to a mailing list could start
+like this, for example:
+
+.. code-block:: python
+
+    from pretix.base.datasync.datasync import (OutboundSyncProvider, datasync_providers)
+
+    @datasync_providers.register
+    class MyListSyncProvider(OutboundSyncProvider):
+        identifier = "my_list"
+        display_name = "My Mailing List Service"
+        # ...
+
+
+The plugin must register listeners in `signals.py` for all signals that should to trigger a sync and
+within it has to call :meth:`MyListSyncProvider.enqueue_order` to enqueue the order for synchronization:
+
+.. code-block:: python
+
+    @receiver(order_placed, dispatch_uid="mylist_order_placed")
+    def on_order_placed(sender, order, **kwargs):
+        MyListSyncProvider.enqueue_order(order, "order_placed")
+
+
+Property mappings
+-----------------
+
+Most of these plugins need to translate data from some pretix objects (e.g. orders)
+into an external system's data structures. Sometimes, there is only one reasonable way or the
+plugin author makes an opinionated decision what information from which objects should be
+transferred into which data structures in the external system.
+
+Otherwise, you can use a :class:`PropertyMappingFormSet` to let the user set up a mapping from pretix model fields
+to external data fields. You could store the mapping information either in the event settings, or in a separate
+data model. Your implementation of :attr:`OutboundSyncProvider.mappings`
+needs to provide a list of mappings, which can be e.g. static objects or model instances, as long as they
+have at least the properties defined in
+:class:`pretix.base.datasync.datasync.StaticMapping`.
+
+.. code-block:: python
+
+    # class MyListSyncProvider, contd.
+        def mappings(self):
+            return [
+                StaticMapping(
+                    id=1, pretix_model='Order', external_object_type='Contact',
+                    pretix_id_field='email', external_id_field='email',
+                    property_mappings=self.event.settings.mylist_order_mapping,
+                ))
+            ]
+
+
+Currently, we support `orders` and `order positions` as data sources, with the data fields defined in
+:func:`pretix.base.datasync.sourcefields.get_data_fields`.
+
+To perform the actual sync, implement :func:`sync_object_with_properties` and optionally
+:func:`finalize_sync_order`. The former is called for each object to be created according to the ``mappings``.
+For each order that was enqueued using :func:`enqueue_order`:
+
+- each Mapping with ``pretix_model == "Order"`` results in one call to :func:`sync_object_with_properties`,
+- each Mapping with ``pretix_model == "OrderPosition"`` results in one call to
+  :func:`sync_object_with_properties` per order position,
+- :func:`finalize_sync_order` is called one time after all calls to :func:`sync_object_with_properties`.
+
+
+Implementation examples
+-----------------------
+
+For example implementations, see the test cases in :mod:`tests.base.test_datasync`.
+
+In :class:`SimpleOrderSync`, a basic data transfer of order data only is
+shown. Therein, a ``sync_object_with_properties`` method is defined as follows:
+
+.. code-block:: python
+
+    from pretix.base.datasync.utils import assign_properties
+
+    # class MyListSyncProvider, contd.
+    def sync_object_with_properties(
+            self, external_id_field, id_value, properties: list, inputs: dict,
+            mapping, mapped_objects: dict, **kwargs,
+    ):
+        # First, we query the external service if our object-to-sync already exists there.
+        # This is necessary to make sure our method is idempotent, i.e. handles already synced
+        # data gracefully.
+        pre_existing_object = self.fake_api_client.retrieve_object(
+            mapping.external_object_type,
+            external_id_field,
+            id_value
+        )
+
+        # We use the helper function ``assign_properties`` to update a pre-existing object.
+        update_values = assign_properties(
+            new_values=properties,
+            old_values=pre_existing_object or {},
+            is_new=pre_existing_object is None,
+            list_sep=";",
+        )
+
+        # Then we can send our new data to the external service. The specifics of course depends
+        # on your API, e.g. you may need to use different endpoints for creating or updating an
+        # object, or pass the identifier separately instead of in the same dictionary as the
+        # other properties.
+        result = self.fake_api_client.create_or_update_object(mapping.external_object_type, {
+            **update_values,
+            external_id_field: id_value,
+            "_id": pre_existing_object and pre_existing_object.get("_id"),
+        })
+
+        # Finally, return a dictionary containing at least `object_type`, `external_id_field`,
+        # `id_value`, `external_link_href`, and `external_link_display_name` keys.
+        # Further keys may be provided for your internal use. This dictionary is provided
+        # in following calls in the ``mapped_objects`` dict, to allow creating associations
+        # to this object.
+        return {
+            "object_type": mapping.external_object_type,
+            "external_id_field": external_id_field,
+            "id_value": id_value,
+            "external_link_href": f"https://example.org/external-system/{mapping.external_object_type}/{id_value}/",
+            "external_link_display_name": f"Contact #{id_value} - Jane Doe",
+            "my_result": result,
+        }
+
+.. note:: The result dictionaries of earlier invocations of :func:`sync_object_with_properties` are
+          only provided in subsequent calls of the same sync run, such that a mapping can
+          refer to e.g. the external id of an object created by a preceding mapping.
+          However, the result dictionaries are currently not provided across runs. This will
+          likely change in a future revision of this API, to allow easier integration of external
+          systems that do not allow retrieving/updating data by a pretix-provided key.
+
+``mapped_objects`` is a dictionary of lists of dictionaries. The keys to the dictionary are
+the mapping identifiers (``mapping.id``), the lists contain the result dictionaries returned
+by :func:`sync_object_with_properties`.
+
+
+In :class:`OrderAndTicketAssociationSync`, an example is given where orders, order positions,
+and the association between them are transferred.
+
+
+The OutboundSyncProvider base class
+-----------------------------------
+
+.. autoclass:: pretix.base.datasync.datasync.OutboundSyncProvider
+   :members:
+
+
+Property mapping format
+-----------------------
+
+To allow the user to configure property mappings, you can use the PropertyMappingFormSet,
+which will generate the required ``property_mappings`` value automatically. If you need
+to specify the property mappings programmatically, you can refer to the description below
+on their format.
+
+.. autoclass:: pretix.control.forms.mapping.PropertyMappingFormSet
+   :members: to_property_mappings_json
+
+A simple JSON-serialized ``property_mappings`` list for mapping some order information can look like this:
+
+.. code-block:: json
+
+      [
+        {
+            "pretix_field": "email",
+            "external_field": "orderemail",
+            "value_map": "",
+            "overwrite": "overwrite",
+        },
+        {
+            "pretix_field": "order_status",
+            "external_field": "status",
+            "value_map": "{\"n\": \"pending\", \"p\": \"paid\", \"e\": \"expired\", \"c\": \"canceled\", \"r\": \"refunded\"}",
+            "overwrite": "overwrite",
+        },
+        {
+            "pretix_field": "order_total",
+            "external_field": "total",
+            "value_map": "",
+            "overwrite": "overwrite",
+        }
+      ]
+
+
+Translating mappings on Event copy
+----------------------------------
+
+Property mappings can contain references to event-specific primary keys. Therefore, plugins must register to the
+event_copy_data signal and call translate_property_mappings on all property mappings they store.
+
+.. autofunction:: pretix.base.datasync.utils.translate_property_mappings

doc/development/api/general.rst

@@ -30,14 +30,14 @@ Check-ins
 
 .. automodule:: pretix.base.signals
    :no-index:
-   :members: checkin_created
+   :members: checkin_created, checkin_annulled
 
 
 Frontend
 --------
 
 .. automodule:: pretix.presale.signals
-   :members: html_head, html_footer, footer_link, global_footer_link, front_page_top, front_page_bottom, front_page_bottom_widget, fee_calculation_for_cart, contact_form_fields, question_form_fields, contact_form_fields_overrides, question_form_fields_overrides, checkout_confirm_messages, checkout_confirm_page_content, checkout_all_optional, html_page_header, render_seating_plan, checkout_flow_steps, position_info, position_info_top, item_description, global_html_head, global_html_footer, global_html_page_header, seatingframe_html_head
+   :members: html_head, html_footer, footer_link, global_footer_link, front_page_top, front_page_bottom, front_page_bottom_widget, fee_calculation_for_cart, contact_form_fields, question_form_fields, contact_form_fields_overrides, question_form_fields_overrides, checkout_confirm_messages, checkout_confirm_page_content, checkout_all_optional, html_page_header, render_seating_plan, checkout_flow_steps, position_info, position_info_top, item_description, global_html_head, global_html_footer, global_html_page_header, seatingframe_html_head, filter_subevents
 
 
 .. automodule:: pretix.presale.signals

doc/development/api/index.rst

@@ -13,10 +13,12 @@ Contents:
    email
    placeholder
    invoice
+   invoicetransmission
    shredder
    import
    customview
    cookieconsent
    auth
+   datasync
    general
    quality

doc/development/api/invoicetransmission.rst

@@ -0,0 +1,65 @@
+.. highlight:: python
+   :linenothreshold: 5
+
+Writing an invoice transmission plugin
+======================================
+
+An invoice transmission provider transports an invoice from the sender to the recipient.
+There are pre-defined types of invoice transmission in pretix, currently ``"email"``, ``"peppol"``, and ``"it_sdi"``.
+You can find more information about them at :ref:`rest-transmission-types`.
+
+New transmission types can not be added by plugins but need to be added to pretix itself.
+However, plugins can provide implementations for the actual transmission.
+Please read :ref:`Creating a plugin <pluginsetup>` first, if you haven't already.
+
+Output registration
+-------------------
+
+New invoice transmission providers can be registered through the :ref:`registry <registries>` mechanism
+
+.. code-block:: python
+
+   from pretix.base.invoicing.transmission import transmission_providers, TransmissionProvider
+
+   @transmission_providers.new()
+   class SdiTransmissionProvider(TransmissionProvider):
+       identifier = "fatturapa_providerabc"
+       type = "it_sdi"
+       verbose_name = _("FatturaPA through provider ABC")
+       ...
+
+
+The provider class
+------------------
+
+.. class:: pretix.base.invoicing.transmission.TransmissionProvider
+
+   .. autoattribute:: identifier
+
+      This is an abstract attribute, you **must** override this!
+
+   .. autoattribute:: type
+
+      This is an abstract attribute, you **must** override this!
+
+   .. autoattribute:: verbose_name
+
+      This is an abstract attribute, you **must** override this!
+
+   .. autoattribute:: priority
+
+   .. autoattribute:: testmode_supported
+
+   .. automethod:: is_ready
+
+      This is an abstract method, you **must** override this!
+
+   .. automethod:: is_available
+
+      This is an abstract method, you **must** override this!
+
+   .. automethod:: transmit
+
+      This is an abstract method, you **must** override this!
+
+   .. automethod:: settings_url

doc/development/api/plugins.rst

@@ -56,6 +56,20 @@ restricted         boolean (optional)   ``False`` by default, restricts a plugin
                                         for an event by system administrators / superusers.
 experimental       boolean (optional)   ``False`` by default, marks a plugin as an experimental feature in the plugins list.
 compatibility      string               Specifier for compatible pretix versions.
+level              string               System level the plugin can be activated at.
+                                        Set to ``pretix.base.plugins.PLUGIN_LEVEL_EVENT`` for plugins that can be activated
+                                        at event level and then be active for that event only.
+                                        Set to ``pretix.base.plugins.PLUGIN_LEVEL_ORGANIZER`` for plugins that can be
+                                        activated only for the organizer as a whole and are active for any event within
+                                        that organizer.
+                                        Set to ``pretix.base.plugins.PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID`` for plugins that
+                                        can be activated at organizer level but are considered active only within events
+                                        for which they have also been specifically activated.
+                                        More levels, e.g. user-level plugins, might be invented in the future.
+settings_links     list                 List of ``((menu name, submenu name, …), urlname, url_kwargs)`` tuples that point
+                                        to the plugin's settings.
+navigation_links   list                 List of ``((menu name, submenu name, …), urlname, url_kwargs)`` tuples that point
+                                        to the plugin's system pages.
 ================== ==================== ===========================================================
 
 A working example would be:
@@ -63,9 +77,9 @@ A working example would be:
 .. code-block:: python
 
     try:
-        from pretix.base.plugins import PluginConfig
+        from pretix.base.plugins import PluginConfig, PLUGIN_LEVEL_EVENT
     except ImportError:
-        raise RuntimeError("Please use pretix 2.7 or above to run this plugin!")
+        raise RuntimeError("Please use pretix 2025.7 or above to run this plugin!")
     from django.utils.translation import gettext_lazy as _
 
 
@@ -79,6 +93,7 @@ A working example would be:
             version = '1.0.0'
             category = 'PAYMENT'
             picture = 'pretix_paypal/paypal_logo.svg'
+            level = PLUGIN_LEVEL_EVENT
             visible = True
             featured = False
             restricted = False
@@ -142,14 +157,14 @@ method to make your receivers available:
             from . import signals  # NOQA
 
 You can optionally specify code that is executed when your plugin is activated for an event
-in the ``installed`` method:
+or organizer in the ``installed`` method:
 
 .. code-block:: python
 
     class PaypalApp(AppConfig):
         …
 
-        def installed(self, event):
+        def installed(self, event_or_organizer):
             pass  # Your code here
 
 

doc/development/setup.rst

@@ -5,7 +5,7 @@ Development setup
 
 This tutorial helps you to get started hacking with pretix on your own computer. You need this to
 be able to contribute to pretix, but it might also be helpful if you want to write your own plugins.
-If you want to install pretix on a server for actual usage, go to the [administrator documentation](https://docs.pretix.eu/self-hosting/) instead.
+If you want to install pretix on a server for actual usage, go to the `administrator documentation`_ instead.
 
 Obtain a copy of the source code
 --------------------------------
@@ -221,3 +221,4 @@ your virtual environment.::
 
 .. _Django's documentation: https://docs.djangoproject.com/en/1.11/ref/django-admin/#runserver
 .. _pretixdroid: https://github.com/pretix/pretixdroid
+.. _administrator documentation: https://docs.pretix.eu/self-hosting/

doc/requirements.rtd.txt

@@ -6,4 +6,4 @@ sphinxcontrib-images
 sphinxcontrib-jquery
 sphinxcontrib-spelling==8.*
 sphinxemoji
-pyenchant==3.2.*
+pyenchant==3.3.*

doc/requirements.txt

@@ -7,4 +7,4 @@ sphinxcontrib-images
 sphinxcontrib-jquery
 sphinxcontrib-spelling==8.*
 sphinxemoji
-pyenchant==3.2.*
+pyenchant==3.3.*

pyproject.toml

@@ -33,18 +33,18 @@ dependencies = [
   "celery==5.5.*",
   "chardet==5.2.*",
   "cryptography>=44.0.0",
-  "css-inline==0.14.*",
+  "css-inline==0.17.*",
   "defusedcsv>=1.1.0",
-  "Django[argon2]==4.2.*,>=4.2.15",
-  "django-bootstrap3==25.1",
+  "Django[argon2]==4.2.*,>=4.2.24",
+  "django-bootstrap3==25.2",
   "django-compressor==4.5.1",
   "django-countries==7.6.*",
   "django-filter==25.1",
-  "django-formset-js-improved==0.5.0.3",
+  "django-formset-js-improved==0.5.0.4",
   "django-formtools==2.5.1",
-  "django-hierarkey==1.2.*",
+  "django-hierarkey==2.0.*,>=2.0.1",
   "django-hijack==3.7.*",
-  "django-i18nfield==1.10.*",
+  "django-i18nfield==1.11.*",
   "django-libsass==0.9",
   "django-localflavor==5.0",
   "django-markup",
@@ -64,7 +64,7 @@ dependencies = [
   "kombu==5.5.*",
   "libsass==0.23.*",
   "lxml",
-  "markdown==3.8",  # 3.3.5 requires importlib-metadata>=4.4, but django-bootstrap3 requires importlib-metadata<3.
+  "markdown==3.9",  # 3.3.5 requires importlib-metadata>=4.4, but django-bootstrap3 requires importlib-metadata<3.
   # We can upgrade markdown again once django-bootstrap3 upgrades or once we drop Python 3.6 and 3.7
   "mt-940==4.30.*",
   "oauthlib==3.3.*",
@@ -74,24 +74,24 @@ dependencies = [
   "paypal-checkout-serversdk==1.0.*",
   "PyJWT==2.10.*",
   "phonenumberslite==9.0.*",
-  "Pillow==11.2.*",
+  "Pillow==11.3.*",
   "pretix-plugin-build",
-  "protobuf==6.31.*",
+  "protobuf==6.32.*",
   "psycopg2-binary",
   "pycountry",
-  "pycparser==2.22",
+  "pycparser==2.23",
   "pycryptodome==3.23.*",
-  "pypdf==5.6.*",
+  "pypdf==6.0.*",
   "python-bidi==0.6.*",  # Support for Arabic in reportlab
   "python-dateutil==2.9.*",
   "pytz",
   "pytz-deprecation-shim==0.1.*",
   "pyuca",
   "qrcode==8.2",
-  "redis==6.2.*",
+  "redis==6.4.*",
   "reportlab==4.4.*",
-  "requests==2.31.*",
-  "sentry-sdk==2.30.*",
+  "requests==2.32.*",
+  "sentry-sdk==2.38.*",
   "sepaxml==2.6.*",
   "stripe==7.9.*",
   "text-unidecode==1.*",
@@ -100,7 +100,7 @@ dependencies = [
   "ua-parser==1.0.*",
   "vat_moss_forked==2020.3.20.0.11.0",
   "vobject==0.9.*",
-  "webauthn==2.5.*",
+  "webauthn==2.7.*",
   "zeep==4.3.*"
 ]
 
@@ -110,8 +110,8 @@ dev = [
   "aiohttp==3.12.*",
   "coverage",
   "coveralls",
-  "fakeredis==2.30.*",
-  "flake8==7.2.*",
+  "fakeredis==2.31.*",
+  "flake8==7.3.*",
   "freezegun",
   "isort==6.0.*",
   "pep8-naming==0.15.*",
@@ -120,9 +120,9 @@ dev = [
   "pytest-cache",
   "pytest-cov",
   "pytest-django==4.*",
-  "pytest-mock==3.14.*",
+  "pytest-mock==3.15.*",
   "pytest-sugar",
-  "pytest-xdist==3.7.*",
+  "pytest-xdist==3.8.*",
   "pytest==8.4.*",
   "responses",
 ]

src/Makefile

@@ -25,8 +25,8 @@ coverage:
 	coverage run -m py.test
 
 npminstall:
-	# keep this in sync with setup.py!
+	# keep this in sync with pretix/_build.py!
 	mkdir -p pretix/static.dist/node_prefix/
 	cp -r pretix/static/npm_dir/* pretix/static.dist/node_prefix/
-	npm install --prefix=pretix/static.dist/node_prefix
+	npm ci --prefix=pretix/static.dist/node_prefix
 

src/pretix/__init__.py

@@ -19,4 +19,4 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
-__version__ = "2025.6.0.dev0"
+__version__ = "2025.8.2"

src/pretix/_base_settings.py

@@ -115,6 +115,7 @@ ALL_LANGUAGES = [
     ('sk', _('Slovak')),
     ('sv', _('Swedish')),
     ('es', _('Spanish')),
+    ('es-419', _('Spanish (Latin America)')),
     ('tr', _('Turkish')),
     ('uk', _('Ukrainian')),
 ]
@@ -172,6 +173,12 @@ EXTRA_LANG_INFO = {
         'name': 'Norwegian Bokmal',
         'name_local': 'norsk (bokmål)',
     },
+    'es-419': {
+        'bidi': False,
+        'code': 'es-419',
+        'name': 'Spanish (Latin America)',
+        'name_local': 'Español',
+    },
 }
 
 django.conf.locale.LANG_INFO.update(EXTRA_LANG_INFO)

src/pretix/_build.py

@@ -39,7 +39,7 @@ def npm_install():
         node_prefix = os.path.join(here, 'static.dist', 'node_prefix')
         os.makedirs(node_prefix, exist_ok=True)
         shutil.copytree(os.path.join(here, 'static', 'npm_dir'), node_prefix, dirs_exist_ok=True)
-        subprocess.check_call('npm install', shell=True, cwd=node_prefix)
+        subprocess.check_call('npm ci', shell=True, cwd=node_prefix)
         npm_installed = True
 
 

src/pretix/api/migrations/0013_alter_webhookcallretry_retry_not_before.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.2.17 on 2025-06-24 14:13
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixapi", "0012_oauthapplication_post_logout_redirect_uris"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="webhookcallretry",
+            name="retry_not_before",
+            field=models.DateTimeField(),
+        ),
+    ]

src/pretix/api/models.py

@@ -157,7 +157,7 @@ class WebHookCallRetry(models.Model):
     id = models.BigAutoField(primary_key=True)
     webhook = models.ForeignKey('WebHook', on_delete=models.CASCADE, related_name='retries')
     logentry = models.ForeignKey('pretixbase.LogEntry', on_delete=models.CASCADE, related_name='webhook_retries')
-    retry_not_before = models.DateTimeField(auto_now_add=True)
+    retry_not_before = models.DateTimeField()
     retry_count = models.PositiveIntegerField(default=0)
     action_type = models.CharField(max_length=255)
 

src/pretix/api/serializers/__init__.py

@@ -23,7 +23,7 @@ import json
 
 from django.db.models import prefetch_related_objects
 from rest_framework import serializers
-from rest_framework.exceptions import PermissionDenied, ValidationError
+from rest_framework.exceptions import ValidationError
 
 
 class AsymmetricField(serializers.Field):
@@ -132,136 +132,6 @@ class SalesChannelMigrationMixin:
                 s.identifier for s in
                 self.organizer.sales_channels.all()
             ])
-        elif "limit_sales_channels" in value:
+        else:
             value["sales_channels"] = value["limit_sales_channels"]
         return value
-
-
-class ConfigurableSerializerMixin:
-    expand_fields = {}
-
-    def get_exclude_requests(self):
-        if hasattr(self, "initial_data"):
-            # Do not support include requests when the serializer is used for writing
-            # TODO: think about this
-            return set()
-        if getattr(self, "parent", None):
-            # Field selection is always handled by top-level serializer
-            return set()
-        if 'exclude' in self.context:
-            return self.context['exclude']
-        elif 'request' in self.context:
-            return self.context['request'].query_params.getlist('exclude')
-        raise TypeError("Could not discover list of fields to exclude")
-
-    def get_include_requests(self):
-        if hasattr(self, "initial_data"):
-            # Do not support include requests when the serializer is used for writing
-            # TODO: think about this
-            return set()
-        if getattr(self, "parent", None):
-            # Field selection is always handled by top-level serializer
-            return set()
-        if 'include' in self.context:
-            return self.context['include']
-        elif 'request' in self.context:
-            return self.context['request'].query_params.getlist('include')
-        raise TypeError("Could not discover list of fields to include")
-
-    def get_expand_requests(self):
-        if hasattr(self, "initial_data"):
-            # Do not support expand requests when the serializer is used for writing
-            # TODO: think about this
-            return set()
-        if getattr(self, "parent", None):
-            # Field selection is always handled by top-level serializer
-            return set()
-        if 'expand' in self.context:
-            return self.context['expand']
-        elif 'request' in self.context:
-            return self.context['request'].query_params.getlist('expand')
-        raise TypeError("Could not discover list of fields to expand")
-
-    def _exclude_field(self, serializer, path):
-        if path[0] not in serializer.fields:
-            return  # field does not exist, nothing to do
-
-        if len(path) == 1:
-            del serializer.fields[path[0]]
-        elif len(path) >= 2 and hasattr(serializer.fields[path[0]], "child"):
-            self._exclude_field(serializer.fields[path[0]].child, path[1:])
-        elif len(path) >= 2 and isinstance(serializer.fields[path[0]], serializers.Serializer):
-            self._exclude_field(serializer.fields[path[0]], path[1:])
-
-    def _filter_fields_to_included(self, serializer, includes):
-        any_field_remaining = False
-        for fname, field in list(serializer.fields.items()):
-            if fname in includes:
-                any_field_remaining = True
-                continue
-            elif hasattr(field, 'child'):  # Nested list serializers
-                child_includes = {i.removeprefix(f'{fname}.') for i in includes if i.startswith(f'{fname}.')}
-                if child_includes and self._filter_fields_to_included(field.child, child_includes):
-                    any_field_remaining = True
-                    continue
-                serializer.fields.pop(fname)
-            elif isinstance(field, serializers.Serializer):  # Nested serializers
-                child_includes = {i.removeprefix(f'{fname}.') for i in includes if i.startswith(f'{fname}.')}
-                if child_includes and self._filter_fields_to_included(field, child_includes):
-                    any_field_remaining = True
-                    continue
-                serializer.fields.pop(fname)
-            else:
-                serializer.fields.pop(fname)
-        return any_field_remaining
-
-    def _expand_field(self, serializer, path, original_field):
-        if path[0] not in serializer.fields or not self.is_field_expandable(original_field):
-            return False  # field does not exist, nothing to do
-
-        if len(path) == 1:
-            serializer.fields[path[0]] = self.get_expand_serializer(original_field)
-            return True
-        elif len(path) >= 2 and hasattr(serializer.fields[path[0]], "child"):
-            return self._expand_field(serializer.fields[path[0]].child, path[1:], original_field)
-        elif len(path) >= 2 and isinstance(serializer.fields[path[0]], serializers.Serializer):
-            return self._expand_field(serializer.fields[path[0]], path[1:], original_field)
-
-    def is_field_expandable(self, field):
-        return field in self.expand_fields
-
-    def get_expand_serializer(self, field):
-        from pretix.base.models import Device, TeamAPIToken
-
-        ef = self.expand_fields[field]
-        if "permission" in ef:
-            request = self.context["request"]
-            perm_holder = request.auth if isinstance(request.auth, (Device, TeamAPIToken)) else request.user
-            if not perm_holder.has_event_permission(request.organizer, request.event, ef["permission"], request=request):
-                raise PermissionDenied(f"No permission to expand field {field}")
-
-        if hasattr(self, "instance") and "prefetch" in ef:
-            for prefetch in ef["prefetch"]:
-                prefetch_related_objects(
-                    self.instance if hasattr(self.instance, '__iter__') else [self.instance],
-                    prefetch
-                )
-
-        return ef["serializer"](
-            read_only=True,
-            context=self.context,
-        )
-
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-
-        expanded = False
-        for expand in sorted(list(self.get_expand_requests())):
-            expanded = self._expand_field(self, expand.split('.'), expand) or expanded
-
-        includes = set(self.get_include_requests())
-        if includes:
-            self._filter_fields_to_included(self, includes)
-
-        for exclude_field in self.get_exclude_requests():
-            self._exclude_field(self, exclude_field.split('.'))

src/pretix/api/serializers/checkin.py

@@ -23,19 +23,15 @@ from django.utils.translation import gettext as _
 from rest_framework import serializers
 from rest_framework.exceptions import ValidationError
 
-from pretix.api.serializers import ConfigurableSerializerMixin
 from pretix.api.serializers.event import SubEventSerializer
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.base.media import MEDIA_TYPES
 from pretix.base.models import Checkin, CheckinList
 
 
-class CheckinListSerializer(ConfigurableSerializerMixin, I18nAwareModelSerializer):
+class CheckinListSerializer(I18nAwareModelSerializer):
     checkin_count = serializers.IntegerField(read_only=True)
     position_count = serializers.IntegerField(read_only=True)
-    expand_fields = {
-        "subevent": SubEventSerializer,
-    }
 
     class Meta:
         model = CheckinList
@@ -46,6 +42,17 @@ class CheckinListSerializer(ConfigurableSerializerMixin, I18nAwareModelSerialize
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
+        if 'subevent' in self.context['request'].query_params.getlist('expand'):
+            self.fields['subevent'] = SubEventSerializer(read_only=True)
+
+        for exclude_field in self.context['request'].query_params.getlist('exclude'):
+            p = exclude_field.split('.')
+            if p[0] in self.fields:
+                if len(p) == 1:
+                    del self.fields[p[0]]
+                elif len(p) == 2:
+                    self.fields[p[0]].child.fields.pop(p[1])
+
     def validate(self, data):
         data = super().validate(data)
         event = self.context['event']
@@ -97,3 +104,14 @@ class MiniCheckinListSerializer(I18nAwareModelSerializer):
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+
+
+class CheckinRPCAnnulInputSerializer(serializers.Serializer):
+    lists = serializers.PrimaryKeyRelatedField(required=True, many=True, queryset=CheckinList.objects.none())
+    nonce = serializers.CharField(required=True, allow_null=False)
+    datetime = serializers.DateTimeField(required=False, allow_null=True)
+    error_explanation = serializers.CharField(required=False, allow_null=True)
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['lists'].child_relation.queryset = CheckinList.objects.filter(event__in=self.context['events']).select_related('event')

src/pretix/api/serializers/event.py

@@ -48,9 +48,9 @@ from rest_framework.fields import ChoiceField, Field
 from rest_framework.relations import SlugRelatedField
 
 from pretix.api.serializers import (
-    CompatibleJSONField, ConfigurableSerializerMixin,
-    SalesChannelMigrationMixin,
+    CompatibleJSONField, SalesChannelMigrationMixin,
 )
+from pretix.api.serializers.fields import PluginsField
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.api.serializers.settings import SettingsSerializer
 from pretix.base.models import (
@@ -62,6 +62,9 @@ from pretix.base.models.items import (
     ItemMetaProperty, SubEventItem, SubEventItemVariation,
 )
 from pretix.base.models.tax import CustomRulesValidator
+from pretix.base.plugins import (
+    PLUGIN_LEVEL_EVENT, PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID,
+)
 from pretix.base.services.seating import (
     SeatProtected, generate_seats, validate_plan_change,
 )
@@ -127,22 +130,6 @@ class SeatCategoryMappingField(Field):
         }
 
 
-class PluginsField(Field):
-
-    def to_representation(self, obj):
-        from pretix.base.plugins import get_all_plugins
-
-        return sorted([
-            p.module for p in get_all_plugins()
-            if not p.name.startswith('.') and getattr(p, 'visible', True) and p.module in obj.get_plugins()
-        ])
-
-    def to_internal_value(self, data):
-        return {
-            'plugins': data
-        }
-
-
 class TimeZoneField(ChoiceField):
     def get_attribute(self, instance):
         return instance.cache.get_or_set(
@@ -168,7 +155,7 @@ class ValidKeysField(Field):
         }
 
 
-class EventSerializer(SalesChannelMigrationMixin, ConfigurableSerializerMixin, I18nAwareModelSerializer):
+class EventSerializer(SalesChannelMigrationMixin, I18nAwareModelSerializer):
     meta_data = MetaDataField(required=False, source='*')
     item_meta_properties = MetaPropertyField(required=False, source='*')
     plugins = PluginsField(required=False, source='*')
@@ -199,11 +186,10 @@ class EventSerializer(SalesChannelMigrationMixin, ConfigurableSerializerMixin, I
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         if not hasattr(self.context['request'], 'event'):
-            self.fields.pop('valid_keys', None)
+            self.fields.pop('valid_keys')
         if not self.context.get('request') or 'with_availability_for' not in self.context['request'].GET:
-            self.fields.pop('best_availability_state', None)
-        if 'limit_sales_channels' in self.fields:
-            self.fields['limit_sales_channels'].child_relation.queryset = self.context['organizer'].sales_channels.all()
+            self.fields.pop('best_availability_state')
+        self.fields['limit_sales_channels'].child_relation.queryset = self.context['organizer'].sales_channels.all()
 
     def validate(self, data):
         data = super().validate(data)
@@ -285,17 +271,28 @@ class EventSerializer(SalesChannelMigrationMixin, ConfigurableSerializerMixin, I
         from pretix.base.plugins import get_all_plugins
 
         plugins_available = {
-            p.module: p for p in get_all_plugins(self.instance)
+            p.module: p for p in get_all_plugins(event=self.instance)
             if not p.name.startswith('.') and getattr(p, 'visible', True)
         }
+        current_plugins = self.instance.get_plugins() if self.instance and self.instance.pk else []
         settings_holder = self.instance if self.instance and self.instance.pk else self.context['organizer']
 
+        allowed_levels = (PLUGIN_LEVEL_EVENT, PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID)
         for plugin in value.get('plugins'):
             if plugin not in plugins_available:
                 raise ValidationError(_('Unknown plugin: \'{name}\'.').format(name=plugin))
             if getattr(plugins_available[plugin], 'restricted', False):
                 if plugin not in settings_holder.settings.allowed_restricted_plugins:
                     raise ValidationError(_('Restricted plugin: \'{name}\'.').format(name=plugin))
+            level = getattr(plugins_available[plugin], 'level', PLUGIN_LEVEL_EVENT)
+            if level not in allowed_levels:
+                raise ValidationError('Plugin cannot be enabled on this level: \'{name}\'.'.format(name=plugin))
+
+            if level == PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID and plugin not in self.context['organizer'].get_plugins():
+                if plugin not in current_plugins:
+                    # Technically, this is allowed, but consumers might be confused if the API call doesn't do anything
+                    # so we prevent this change.
+                    raise ValidationError('Plugin should be enabled on organizer level first: \'{name}\'.'.format(name=plugin))
 
         return value
 
@@ -485,7 +482,7 @@ class SubEventItemVariationSerializer(I18nAwareModelSerializer):
         fields = ('variation', 'price', 'disabled', 'available_from', 'available_until')
 
 
-class SubEventSerializer(ConfigurableSerializerMixin, I18nAwareModelSerializer):
+class SubEventSerializer(I18nAwareModelSerializer):
     item_price_overrides = SubEventItemSerializer(source='subeventitem_set', many=True, required=False)
     variation_price_overrides = SubEventItemVariationSerializer(source='subeventitemvariation_set', many=True, required=False)
     seat_category_mapping = SeatCategoryMappingField(source='*', required=False)
@@ -504,7 +501,7 @@ class SubEventSerializer(ConfigurableSerializerMixin, I18nAwareModelSerializer):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         if not self.context.get('request') or 'with_availability_for' not in self.context['request'].GET:
-            self.fields.pop('best_availability_state', None)
+            self.fields.pop('best_availability_state')
 
     def validate(self, data):
         data = super().validate(data)
@@ -687,8 +684,26 @@ class TaxRuleSerializer(CountryFieldMixin, I18nAwareModelSerializer):
 
     class Meta:
         model = TaxRule
-        fields = ('id', 'name', 'rate', 'code', 'price_includes_tax', 'eu_reverse_charge', 'home_country',
-                  'internal_name', 'keep_gross_if_rate_changes', 'custom_rules')
+        fields = ('id', 'name', 'default', 'rate', 'code', 'price_includes_tax', 'eu_reverse_charge', 'home_country',
+                  'internal_name', 'keep_gross_if_rate_changes', 'custom_rules', 'default')
+
+    def create(self, validated_data):
+        if "default" not in validated_data and not self.context["event"].tax_rules.exists():
+            validated_data["default"] = True
+        return super().create(validated_data)
+
+    def save(self, **kwargs):
+        if self.validated_data.get("default"):
+            if self.instance and self.instance.pk:
+                self.context["event"].tax_rules.exclude(pk=self.instance.pk).update(default=False)
+            else:
+                self.context["event"].tax_rules.update(default=False)
+        return super().save(**kwargs)
+
+    def validate_default(self, value):
+        if not value and self.instance.default:
+            raise ValidationError("You can't remove the default property, instead set it on another tax rule.")
+        return value
 
 
 class EventSettingsSerializer(SettingsSerializer):
@@ -714,6 +729,8 @@ class EventSettingsSerializer(SettingsSerializer):
         'allow_modifications_after_checkin',
         'last_order_modification_date',
         'show_quota_left',
+        'tax_rule_payment',
+        'tax_rule_cancellation',
         'waiting_list_enabled',
         'waiting_list_auto_disable',
         'waiting_list_hours',
@@ -944,6 +961,8 @@ class DeviceEventSettingsSerializer(EventSettingsSerializer):
         'reusable_media_type_nfc_mf0aes',
         'reusable_media_type_nfc_mf0aes_random_uid',
         'system_question_order',
+        'tax_rule_payment',
+        'tax_rule_cancellation',
     ]
 
     def __init__(self, *args, **kwargs):

src/pretix/api/serializers/exporters.py

@@ -19,45 +19,16 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
-from django import forms
 from django.conf import settings
 from django.http import QueryDict
 from pytz import common_timezones
 from rest_framework import serializers
 from rest_framework.exceptions import ValidationError
 
+from pretix.api.serializers.forms import form_field_to_serializer_field
 from pretix.base.exporter import OrganizerLevelExportMixin
 from pretix.base.models import ScheduledEventExport, ScheduledOrganizerExport
-from pretix.base.timeframes import DateFrameField, SerializerDateFrameField
-
-
-class FormFieldWrapperField(serializers.Field):
-    def __init__(self, *args, **kwargs):
-        self.form_field = kwargs.pop('form_field')
-        super().__init__(*args, **kwargs)
-
-    def to_representation(self, value):
-        return self.form_field.widget.format_value(value)
-
-    def to_internal_value(self, data):
-        d = self.form_field.widget.value_from_datadict({'name': data}, {}, 'name')
-        d = self.form_field.clean(d)
-        return d
-
-
-simple_mappings = (
-    (forms.DateField, serializers.DateField, ()),
-    (forms.TimeField, serializers.TimeField, ()),
-    (forms.SplitDateTimeField, serializers.DateTimeField, ()),
-    (forms.DateTimeField, serializers.DateTimeField, ()),
-    (forms.DecimalField, serializers.DecimalField, ('max_digits', 'decimal_places', 'min_value', 'max_value')),
-    (forms.FloatField, serializers.FloatField, ()),
-    (forms.IntegerField, serializers.IntegerField, ()),
-    (forms.EmailField, serializers.EmailField, ()),
-    (forms.UUIDField, serializers.UUIDField, ()),
-    (forms.URLField, serializers.URLField, ()),
-    (forms.BooleanField, serializers.BooleanField, ()),
-)
+from pretix.base.timeframes import SerializerDateFrameField
 
 
 class SerializerDescriptionField(serializers.Field):
@@ -81,13 +52,6 @@ class ExporterSerializer(serializers.Serializer):
     input_parameters = SerializerDescriptionField(source='_serializer')
 
 
-class PrimaryKeyRelatedField(serializers.PrimaryKeyRelatedField):
-    def to_representation(self, value):
-        if isinstance(value, int):
-            return value
-        return super().to_representation(value)
-
-
 class JobRunSerializer(serializers.Serializer):
     def __init__(self, *args, **kwargs):
         ex = kwargs.pop('exporter')
@@ -102,59 +66,7 @@ class JobRunSerializer(serializers.Serializer):
                 many=True
             )
         for k, v in ex.export_form_fields.items():
-            for m_from, m_to, m_kwargs in simple_mappings:
-                if isinstance(v, m_from):
-                    self.fields[k] = m_to(
-                        required=v.required,
-                        allow_null=not v.required,
-                        validators=v.validators,
-                        **{kwarg: getattr(v, kwargs, None) for kwarg in m_kwargs}
-                    )
-                    break
-
-            if isinstance(v, forms.NullBooleanField):
-                self.fields[k] = serializers.BooleanField(
-                    required=v.required,
-                    allow_null=True,
-                    validators=v.validators,
-                )
-            if isinstance(v, forms.ModelMultipleChoiceField):
-                self.fields[k] = PrimaryKeyRelatedField(
-                    queryset=v.queryset,
-                    required=v.required,
-                    allow_empty=not v.required,
-                    validators=v.validators,
-                    many=True
-                )
-            elif isinstance(v, forms.ModelChoiceField):
-                self.fields[k] = PrimaryKeyRelatedField(
-                    queryset=v.queryset,
-                    required=v.required,
-                    allow_null=not v.required,
-                    validators=v.validators,
-                )
-            elif isinstance(v, forms.MultipleChoiceField):
-                self.fields[k] = serializers.MultipleChoiceField(
-                    choices=v.choices,
-                    required=v.required,
-                    allow_empty=not v.required,
-                    validators=v.validators,
-                )
-            elif isinstance(v, forms.ChoiceField):
-                self.fields[k] = serializers.ChoiceField(
-                    choices=v.choices,
-                    required=v.required,
-                    allow_null=not v.required,
-                    validators=v.validators,
-                )
-            elif isinstance(v, DateFrameField):
-                self.fields[k] = SerializerDateFrameField(
-                    required=v.required,
-                    allow_null=not v.required,
-                    validators=v.validators,
-                )
-            else:
-                self.fields[k] = FormFieldWrapperField(form_field=v, required=v.required, allow_null=not v.required)
+            self.fields[k] = form_field_to_serializer_field(v)
 
     def to_internal_value(self, data):
         if isinstance(data, QueryDict):

src/pretix/api/serializers/fields.py

@@ -109,3 +109,19 @@ class UploadedFileField(serializers.Field):
             return None
         request = self.context['request']
         return request.build_absolute_uri(url)
+
+
+class PluginsField(serializers.Field):
+
+    def to_representation(self, obj):
+        from pretix.base.plugins import get_all_plugins
+
+        return sorted([
+            p.module for p in get_all_plugins()
+            if not p.name.startswith('.') and getattr(p, 'visible', True) and p.module in obj.get_plugins()
+        ])
+
+    def to_internal_value(self, data):
+        return {
+            'plugins': data
+        }

src/pretix/api/serializers/forms.py

@@ -0,0 +1,115 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+from django import forms
+from rest_framework import serializers
+
+from pretix.base.timeframes import DateFrameField, SerializerDateFrameField
+
+simple_mappings = (
+    (forms.DateField, serializers.DateField, ()),
+    (forms.TimeField, serializers.TimeField, ()),
+    (forms.SplitDateTimeField, serializers.DateTimeField, ()),
+    (forms.DateTimeField, serializers.DateTimeField, ()),
+    (forms.DecimalField, serializers.DecimalField, ('max_digits', 'decimal_places', 'min_value', 'max_value')),
+    (forms.FloatField, serializers.FloatField, ()),
+    (forms.IntegerField, serializers.IntegerField, ()),
+    (forms.EmailField, serializers.EmailField, ()),
+    (forms.UUIDField, serializers.UUIDField, ()),
+    (forms.URLField, serializers.URLField, ()),
+    (forms.BooleanField, serializers.BooleanField, ()),
+)
+
+
+class PrimaryKeyRelatedField(serializers.PrimaryKeyRelatedField):
+    def to_representation(self, value):
+        if isinstance(value, int):
+            return value
+        return super().to_representation(value)
+
+
+class FormFieldWrapperField(serializers.Field):
+    def __init__(self, *args, **kwargs):
+        self.form_field = kwargs.pop('form_field')
+        super().__init__(*args, **kwargs)
+
+    def to_representation(self, value):
+        return self.form_field.widget.format_value(value)
+
+    def to_internal_value(self, data):
+        d = self.form_field.widget.value_from_datadict({'name': data}, {}, 'name')
+        d = self.form_field.clean(d)
+        return d
+
+
+def form_field_to_serializer_field(field):
+    for m_from, m_to, m_kwargs in simple_mappings:
+        if isinstance(field, m_from):
+            return m_to(
+                required=field.required,
+                allow_null=not field.required,
+                validators=field.validators,
+                **{kwarg: getattr(field, kwarg, None) for kwarg in m_kwargs}
+            )
+
+    if isinstance(field, forms.NullBooleanField):
+        return serializers.BooleanField(
+            required=field.required,
+            allow_null=True,
+            validators=field.validators,
+        )
+    if isinstance(field, forms.ModelMultipleChoiceField):
+        return PrimaryKeyRelatedField(
+            queryset=field.queryset,
+            required=field.required,
+            allow_empty=not field.required,
+            validators=field.validators,
+            many=True
+        )
+    elif isinstance(field, forms.ModelChoiceField):
+        return PrimaryKeyRelatedField(
+            queryset=field.queryset,
+            required=field.required,
+            allow_null=not field.required,
+            validators=field.validators,
+        )
+    elif isinstance(field, forms.MultipleChoiceField):
+        return serializers.MultipleChoiceField(
+            choices=field.choices,
+            required=field.required,
+            allow_empty=not field.required,
+            validators=field.validators,
+        )
+    elif isinstance(field, forms.ChoiceField):
+        return serializers.ChoiceField(
+            choices=field.choices,
+            required=field.required,
+            allow_null=not field.required,
+            validators=field.validators,
+        )
+    elif isinstance(field, DateFrameField):
+        return SerializerDateFrameField(
+            required=field.required,
+            allow_null=not field.required,
+            validators=field.validators,
+        )
+    else:
+        return FormFieldWrapperField(form_field=field, required=field.required, allow_null=not field.required)

src/pretix/api/serializers/item.py

@@ -42,10 +42,8 @@ from django.utils.functional import cached_property, lazy
 from django.utils.translation import gettext_lazy as _
 from rest_framework import serializers
 
-from pretix.api.serializers import (
-    ConfigurableSerializerMixin, SalesChannelMigrationMixin,
-)
-from pretix.api.serializers.event import MetaDataField, TaxRuleSerializer
+from pretix.api.serializers import SalesChannelMigrationMixin
+from pretix.api.serializers.event import MetaDataField
 from pretix.api.serializers.fields import UploadedFileField
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.base.models import (
@@ -248,29 +246,7 @@ class ItemTaxRateField(serializers.Field):
             return str(Decimal('0.00'))
 
 
-class ItemCategorySerializer(I18nAwareModelSerializer):
-
-    class Meta:
-        model = ItemCategory
-        fields = (
-            'id', 'name', 'internal_name', 'description', 'position',
-            'is_addon', 'cross_selling_mode',
-            'cross_selling_condition', 'cross_selling_match_products'
-        )
-
-    def validate(self, data):
-        data = super().validate(data)
-
-        full_data = self.to_internal_value(self.to_representation(self.instance)) if self.instance else {}
-        full_data.update(data)
-
-        if full_data.get('is_addon') and full_data.get('cross_selling_mode'):
-            raise ValidationError('is_addon and cross_selling_mode are mutually exclusive')
-
-        return data
-
-
-class ItemSerializer(SalesChannelMigrationMixin, ConfigurableSerializerMixin, I18nAwareModelSerializer):
+class ItemSerializer(SalesChannelMigrationMixin, I18nAwareModelSerializer):
     addons = InlineItemAddOnSerializer(many=True, required=False)
     bundles = InlineItemBundleSerializer(many=True, required=False)
     variations = InlineItemVariationSerializer(many=True, required=False)
@@ -286,16 +262,6 @@ class ItemSerializer(SalesChannelMigrationMixin, ConfigurableSerializerMixin, I1
         allow_empty=True,
         many=True,
     )
-    expand_fields = {
-        "category": {
-            "serializer": ItemCategorySerializer,
-            "prefetch": ["category"],
-        },
-        "tax_rule": {
-            "serializer": TaxRuleSerializer,
-            "prefetch": ["tax_rule"],
-        },
-    }
 
     class Meta:
         model = Item
@@ -318,18 +284,13 @@ class ItemSerializer(SalesChannelMigrationMixin, ConfigurableSerializerMixin, I1
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        if 'default_price' in self.fields:
-            self.fields['default_price'].allow_null = False
-            self.fields['default_price'].required = True
+        self.fields['default_price'].allow_null = False
+        self.fields['default_price'].required = True
         if not self.read_only:
-            if 'require_membership_types' in self.fields:
-                self.fields['require_membership_types'].queryset = self.context['event'].organizer.membership_types.all()
-            if 'grant_membership_type' in self.fields:
-                self.fields['grant_membership_type'].queryset = self.context['event'].organizer.membership_types.all()
-            if 'limit_sales_channels' in self.fields:
-                self.fields['limit_sales_channels'].child_relation.queryset = self.context['event'].organizer.sales_channels.all()
-            if 'variations' in self.fields and 'limit_sales_channels' in self.fields['variations'].child.fields:
-                self.fields['variations'].child.fields['limit_sales_channels'].child_relation.queryset = self.context['event'].organizer.sales_channels.all()
+            self.fields['require_membership_types'].queryset = self.context['event'].organizer.membership_types.all()
+            self.fields['grant_membership_type'].queryset = self.context['event'].organizer.membership_types.all()
+            self.fields['limit_sales_channels'].child_relation.queryset = self.context['event'].organizer.sales_channels.all()
+            self.fields['variations'].child.fields['limit_sales_channels'].child_relation.queryset = self.context['event'].organizer.sales_channels.all()
 
     def validate(self, data):
         data = super().validate(data)
@@ -476,6 +437,28 @@ class ItemSerializer(SalesChannelMigrationMixin, ConfigurableSerializerMixin, I1
         return item
 
 
+class ItemCategorySerializer(I18nAwareModelSerializer):
+
+    class Meta:
+        model = ItemCategory
+        fields = (
+            'id', 'name', 'internal_name', 'description', 'position',
+            'is_addon', 'cross_selling_mode',
+            'cross_selling_condition', 'cross_selling_match_products'
+        )
+
+    def validate(self, data):
+        data = super().validate(data)
+
+        full_data = self.to_internal_value(self.to_representation(self.instance)) if self.instance else {}
+        full_data.update(data)
+
+        if full_data.get('is_addon') and full_data.get('cross_selling_mode'):
+            raise ValidationError('is_addon and cross_selling_mode are mutually exclusive')
+
+        return data
+
+
 class QuestionOptionSerializer(I18nAwareModelSerializer):
     identifier = serializers.CharField(allow_null=True)
 
@@ -522,6 +505,11 @@ class QuestionSerializer(I18nAwareModelSerializer):
         Question._clean_identifier(self.context['event'], value, self.instance)
         return value
 
+    def validate_type(self, value):
+        if self.instance:
+            self.instance.clean_type_change(self.instance.type, value)
+        return value
+
     def validate_dependency_question(self, value):
         if value:
             if value.type not in (Question.TYPE_CHOICE, Question.TYPE_BOOLEAN, Question.TYPE_CHOICE_MULTIPLE):
@@ -594,7 +582,7 @@ class QuotaSerializer(I18nAwareModelSerializer):
     class Meta:
         model = Quota
         fields = ('id', 'name', 'size', 'items', 'variations', 'subevent', 'closed', 'close_when_sold_out',
-                  'release_after_exit', 'available', 'available_number')
+                  'release_after_exit', 'available', 'available_number', 'ignore_for_event_availability')
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)

src/pretix/api/serializers/order.py

@@ -40,18 +40,17 @@ from rest_framework.exceptions import ValidationError
 from rest_framework.relations import SlugRelatedField
 from rest_framework.reverse import reverse
 
-from pretix.api.serializers import (
-    CompatibleJSONField, ConfigurableSerializerMixin,
-)
+from pretix.api.serializers import CompatibleJSONField
 from pretix.api.serializers.event import SubEventSerializer
+from pretix.api.serializers.forms import form_field_to_serializer_field
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.api.serializers.item import (
     InlineItemVariationSerializer, ItemSerializer, QuestionSerializer,
 )
-from pretix.api.serializers.voucher import VoucherSerializer
 from pretix.api.signals import order_api_details, orderposition_api_details
 from pretix.base.decimal import round_decimal
 from pretix.base.i18n import language
+from pretix.base.invoicing.transmission import get_transmission_types
 from pretix.base.models import (
     CachedFile, Checkin, Customer, Invoice, InvoiceAddress, InvoiceLine, Item,
     ItemVariation, Order, OrderPosition, Question, QuestionAnswer,
@@ -59,7 +58,7 @@ from pretix.base.models import (
 )
 from pretix.base.models.orders import (
     BlockedTicketSecret, CartPosition, OrderFee, OrderPayment, OrderRefund,
-    PrintLog, RevokedTicketSecret,
+    PrintLog, RevokedTicketSecret, Transaction,
 )
 from pretix.base.pdf import get_images, get_variables
 from pretix.base.services.cart import error_messages
@@ -105,6 +104,13 @@ class CountryField(serializers.Field):
         return str(src) if src else None
 
 
+class TransmissionInfoSerializer(serializers.Serializer):
+    def __init__(self, *args, transmission_type, **kwargs):
+        super().__init__(*args, **kwargs)
+        for k, v in transmission_type.invoice_address_form_fields.items():
+            self.fields[k] = form_field_to_serializer_field(v)
+
+
 class InvoiceAddressSerializer(I18nAwareModelSerializer):
     country = CompatibleCountryField(source='*')
     name = serializers.CharField(required=False)
@@ -112,7 +118,8 @@ class InvoiceAddressSerializer(I18nAwareModelSerializer):
     class Meta:
         model = InvoiceAddress
         fields = ('last_modified', 'is_business', 'company', 'name', 'name_parts', 'street', 'zipcode', 'city', 'country',
-                  'state', 'vat_id', 'vat_id_validated', 'custom_field', 'internal_reference')
+                  'state', 'vat_id', 'vat_id_validated', 'custom_field', 'internal_reference', 'transmission_type',
+                  'transmission_info')
         read_only_fields = ('last_modified',)
 
     def __init__(self, *args, **kwargs):
@@ -150,6 +157,48 @@ class InvoiceAddressSerializer(I18nAwareModelSerializer):
                     {'state': ['"{}" is not a known subdivision of the country "{}".'.format(data.get('state'), cc)]}
                 )
 
+        if data.get("transmission_type"):
+            for t in get_transmission_types():
+                if data.get("transmission_type") == t.identifier:
+                    if not t.is_available(self.context["request"].event, data.get("country"), data.get("is_business")):
+                        raise ValidationError({
+                            "transmission_type": "The selected transmission type is not available for this country or address type."
+                        })
+
+                    ts = TransmissionInfoSerializer(transmission_type=t, data=data.get("transmission_info", {}))
+                    try:
+                        ts.is_valid(raise_exception=True)
+                    except ValidationError as e:
+                        raise ValidationError(
+                            {"transmission_info": e.detail}
+                        )
+                    data["transmission_info"] = ts.validated_data
+
+                    required_fields = t.invoice_address_form_fields_required(data.get("country"), data.get("is_business"))
+                    for r in required_fields:
+                        if r in self.fields:
+                            if not data.get(r):
+                                raise ValidationError(
+                                    {r: "This field is required for the selected type of invoice transmission."}
+                                )
+                        else:
+                            if not ts.validated_data.get(r):
+                                raise ValidationError(
+                                    {"transmission_info": {r: "This field is required for the selected type of invoice transmission."}}
+                                )
+                    break  # do not call else branch of for loop
+                elif t.exclusive:
+                    if t.is_available(self.context["request"].event, data.get("country"), data.get("is_business")):
+                        raise ValidationError({
+                            "transmission_type": "The transmission type '%s' must be used for this country or address type." % (
+                                t.identifier,
+                            )
+                        })
+            else:
+                raise ValidationError(
+                    {"transmission_type": "Unknown transmission type."}
+                )
+
         return data
 
 
@@ -178,7 +227,7 @@ class AnswerSerializer(I18nAwareModelSerializer):
 
     def to_representation(self, instance):
         r = super().to_representation(instance)
-        if r.get('answer') and r.get('answer').startswith('file://') and instance.orderposition:
+        if r['answer'].startswith('file://') and instance.orderposition:
             r['answer'] = reverse('api-v1:orderposition-answer', kwargs={
                 'organizer': instance.orderposition.order.event.organizer.slug,
                 'event': instance.orderposition.order.event.slug,
@@ -760,7 +809,7 @@ class OrderPluginDataField(serializers.Field):
         return d
 
 
-class OrderSerializer(ConfigurableSerializerMixin, I18nAwareModelSerializer):
+class OrderSerializer(I18nAwareModelSerializer):
     event = SlugRelatedField(slug_field='slug', read_only=True)
     invoice_address = InvoiceAddressSerializer(allow_null=True)
     positions = OrderPositionSerializer(many=True, read_only=True)
@@ -778,39 +827,6 @@ class OrderSerializer(ConfigurableSerializerMixin, I18nAwareModelSerializer):
         required=False,
     )
     plugin_data = OrderPluginDataField(source='*', allow_null=True, read_only=True)
-    expand_fields = {
-        "positions.voucher": {
-            "serializer": VoucherSerializer,
-            "permission": "can_view_vouchers",
-            "prefetch": ["positions__voucher"],
-        },
-        "positions.item": {
-            "serializer": ItemSerializer,
-            "prefetch": [
-                "positions__item",
-                "positions__item__addons",
-                "positions__item__bundles",
-                "positions__item__meta_values",
-                "positions__item__variations",
-                "positions__item__tax_rule",
-            ],
-        },
-        "positions.variation": {
-            "serializer": ItemSerializer,
-            "prefetch": ["positions__variation", "positions__variation__meta_values"],
-        },
-        "positions.subevent": {
-            "serializer": SubEventSerializer,
-            "prefetch": [
-                "positions__subevent",
-                "positions__subevent__event",
-                "positions__subevent__subeventitem_set",
-                "positions__subevent__subeventitemvariation_set",
-                "positions__subevent__seat_category_mappings",
-                "positions__subevent__meta_values",
-            ],
-        },
-    }
 
     class Meta:
         model = Order
@@ -829,14 +845,47 @@ class OrderSerializer(ConfigurableSerializerMixin, I18nAwareModelSerializer):
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        if "sales_channel" in self.fields:
-            if "organizer" in self.context:
-                self.fields["sales_channel"].queryset = self.context["organizer"].sales_channels.all()
-            else:
-                self.fields["sales_channel"].queryset = self.context["event"].organizer.sales_channels.all()
-        if not self.context['pdf_data'] and "positions" in self.fields:
+        if "organizer" in self.context:
+            self.fields["sales_channel"].queryset = self.context["organizer"].sales_channels.all()
+        else:
+            self.fields["sales_channel"].queryset = self.context["event"].organizer.sales_channels.all()
+        if not self.context['pdf_data']:
             self.fields['positions'].child.fields.pop('pdf_data', None)
 
+        includes = set(self.context['include'])
+        if includes:
+            for fname, field in list(self.fields.items()):
+                if fname in includes:
+                    continue
+                elif hasattr(field, 'child'):  # Nested list serializers
+                    found_any = False
+                    for childfname, childfield in list(field.child.fields.items()):
+                        if f'{fname}.{childfname}' not in includes:
+                            field.child.fields.pop(childfname)
+                        else:
+                            found_any = True
+                    if not found_any:
+                        self.fields.pop(fname)
+                elif isinstance(field, serializers.Serializer):  # Nested serializers
+                    found_any = False
+                    for childfname, childfield in list(field.fields.items()):
+                        if f'{fname}.{childfname}' not in includes:
+                            field.fields.pop(childfname)
+                        else:
+                            found_any = True
+                    if not found_any:
+                        self.fields.pop(fname)
+                else:
+                    self.fields.pop(fname)
+
+        for exclude_field in self.context['exclude']:
+            p = exclude_field.split('.')
+            if p[0] in self.fields:
+                if len(p) == 1:
+                    del self.fields[p[0]]
+                elif len(p) == 2:
+                    self.fields[p[0]].child.fields.pop(p[1])
+
     def validate_locale(self, l):
         if l not in set(k for k in self.instance.event.settings.locales):
             raise ValidationError('"{}" is not a supported locale for this event.'.format(l))
@@ -1728,12 +1777,13 @@ class InvoiceSerializer(I18nAwareModelSerializer):
         model = Invoice
         fields = ('event', 'order', 'number', 'is_cancellation', 'invoice_from', 'invoice_from_name', 'invoice_from_zipcode',
                   'invoice_from_city', 'invoice_from_country', 'invoice_from_tax_id', 'invoice_from_vat_id',
-                  'invoice_to', 'invoice_to_company', 'invoice_to_name', 'invoice_to_street', 'invoice_to_zipcode',
-                  'invoice_to_city', 'invoice_to_state', 'invoice_to_country', 'invoice_to_vat_id', 'invoice_to_beneficiary',
-                  'custom_field', 'date', 'refers', 'locale',
+                  'invoice_to', 'invoice_to_is_business', 'invoice_to_company', 'invoice_to_name', 'invoice_to_street',
+                  'invoice_to_zipcode', 'invoice_to_city', 'invoice_to_state', 'invoice_to_country', 'invoice_to_vat_id',
+                  'invoice_to_beneficiary', 'invoice_to_transmission_info', 'custom_field', 'date', 'refers', 'locale',
                   'introductory_text', 'additional_text', 'payment_provider_text', 'payment_provider_stamp',
                   'footer_text', 'lines', 'foreign_currency_display', 'foreign_currency_rate',
-                  'foreign_currency_rate_date', 'internal_reference')
+                  'foreign_currency_rate_date', 'internal_reference', 'transmission_type', 'transmission_provider',
+                  'transmission_status', 'transmission_date')
 
 
 class OrderPaymentCreateSerializer(I18nAwareModelSerializer):
@@ -1786,3 +1836,23 @@ class BlockedTicketSecretSerializer(I18nAwareModelSerializer):
     class Meta:
         model = BlockedTicketSecret
         fields = ('id', 'secret', 'updated', 'blocked')
+
+
+class TransactionSerializer(I18nAwareModelSerializer):
+    order = serializers.SlugRelatedField(slug_field="code", read_only=True)
+
+    class Meta:
+        model = Transaction
+        fields = (
+            "id", "order", "created", "datetime", "positionid", "count", "item", "variation",
+            "subevent", "price", "tax_rate", "tax_rule", "tax_code", "tax_value", "fee_type",
+            "internal_type"
+        )
+
+
+class OrganizerTransactionSerializer(TransactionSerializer):
+    event = serializers.SlugRelatedField(source="order.event", slug_field="slug", read_only=True)
+
+    class Meta:
+        model = Transaction
+        fields = TransactionSerializer.Meta.fields + ("event",)

src/pretix/api/serializers/orderchange.py

@@ -83,6 +83,7 @@ class OrderPositionCreateForExistingOrderSerializer(OrderPositionCreateSerialize
 
     def create(self, validated_data):
         ocm = self.context['ocm']
+        check_quotas = self.context.get('check_quotas', True)
 
         try:
             ocm.add_position(
@@ -96,7 +97,7 @@ class OrderPositionCreateForExistingOrderSerializer(OrderPositionCreateSerialize
                 valid_until=validated_data.get('valid_until'),
             )
             if self.context.get('commit', True):
-                ocm.commit()
+                ocm.commit(check_quotas=check_quotas)
                 return validated_data['order'].positions.order_by('-positionid').first()
             else:
                 return OrderPosition()  # fake to appease DRF
@@ -310,6 +311,7 @@ class OrderPositionChangeSerializer(serializers.ModelSerializer):
 
     def update(self, instance, validated_data):
         ocm = self.context['ocm']
+        check_quotas = self.context.get('check_quotas', True)
         current_seat = {'seat_guid': instance.seat.seat_guid} if instance.seat else None
         item = validated_data.get('item', instance.item)
         variation = validated_data.get('variation', instance.variation)
@@ -356,7 +358,7 @@ class OrderPositionChangeSerializer(serializers.ModelSerializer):
                 ocm.change_ticket_secret(instance, secret)
 
             if self.context.get('commit', True):
-                ocm.commit()
+                ocm.commit(check_quotas=check_quotas)
                 instance.refresh_from_db()
         except OrderError as e:
             raise ValidationError(str(e))

src/pretix/api/serializers/organizer.py

@@ -24,6 +24,7 @@ from decimal import Decimal
 
 from django.conf import settings
 from django.core.exceptions import ObjectDoesNotExist
+from django.db import transaction
 from django.db.models import Q
 from django.utils.crypto import get_random_string
 from django.utils.translation import gettext_lazy as _
@@ -31,7 +32,8 @@ from rest_framework import serializers
 from rest_framework.exceptions import ValidationError
 
 from pretix.api.auth.devicesecurity import get_all_security_profiles
-from pretix.api.serializers import AsymmetricField, ConfigurableSerializerMixin
+from pretix.api.serializers import AsymmetricField
+from pretix.api.serializers.fields import PluginsField
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.api.serializers.order import CompatibleJSONField
 from pretix.api.serializers.settings import SettingsSerializer
@@ -43,6 +45,10 @@ from pretix.base.models import (
     SalesChannel, SeatingPlan, Team, TeamAPIToken, TeamInvite, User,
 )
 from pretix.base.models.seating import SeatingPlanLayoutValidator
+from pretix.base.plugins import (
+    PLUGIN_LEVEL_EVENT, PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID,
+    PLUGIN_LEVEL_ORGANIZER,
+)
 from pretix.base.services.mail import SendMailException, mail
 from pretix.base.settings import validate_organizer_settings
 from pretix.helpers.urls import build_absolute_uri as build_global_uri
@@ -51,15 +57,49 @@ from pretix.multidomain.urlreverse import build_absolute_uri
 logger = logging.getLogger(__name__)
 
 
-class OrganizerSerializer(ConfigurableSerializerMixin, I18nAwareModelSerializer):
+class OrganizerSerializer(I18nAwareModelSerializer):
     public_url = serializers.SerializerMethodField('get_organizer_url', read_only=True)
+    plugins = PluginsField(required=False, source='*')
+    name = serializers.CharField(read_only=True)
+    slug = serializers.CharField(read_only=True)
 
     def get_organizer_url(self, organizer):
         return build_absolute_uri(organizer, 'presale:organizer.index')
 
     class Meta:
         model = Organizer
-        fields = ('name', 'slug', 'public_url')
+        fields = ('name', 'slug', 'public_url', 'plugins')
+
+    def validate_plugins(self, value):
+        from pretix.base.plugins import get_all_plugins
+
+        plugins_available = {
+            p.module: p for p in get_all_plugins(organizer=self.instance)
+            if not p.name.startswith('.') and getattr(p, 'visible', True)
+        }
+        settings_holder = self.instance
+
+        allowed_levels = (PLUGIN_LEVEL_ORGANIZER, PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID)
+        for plugin in value.get('plugins'):
+            if plugin not in plugins_available:
+                raise ValidationError(_('Unknown plugin: \'{name}\'.').format(name=plugin))
+            if getattr(plugins_available[plugin], 'restricted', False):
+                if plugin not in settings_holder.settings.allowed_restricted_plugins:
+                    raise ValidationError(_('Restricted plugin: \'{name}\'.').format(name=plugin))
+            if getattr(plugins_available[plugin], 'level', PLUGIN_LEVEL_EVENT) not in allowed_levels:
+                raise ValidationError('Plugin cannot be enabled on this level: \'{name}\'.'.format(name=plugin))
+
+        return value
+
+    @transaction.atomic
+    def update(self, instance, validated_data):
+        plugins = validated_data.pop('plugins', None)
+        organizer = super().update(instance, validated_data)
+        # Plugins
+        if plugins is not None:
+            organizer.set_active_plugins(plugins)
+            organizer.save()
+        return organizer
 
 
 class SeatingPlanSerializer(I18nAwareModelSerializer):
@@ -444,6 +484,7 @@ class OrganizerSettingsSerializer(SettingsSerializer):
         'reusable_media_type_nfc_mf0aes',
         'reusable_media_type_nfc_mf0aes_autocreate_giftcard',
         'reusable_media_type_nfc_mf0aes_autocreate_giftcard_currency',
+        'reusable_media_type_nfc_mf0aes_random_uid',
     ]
 
     def __init__(self, *args, **kwargs):

src/pretix/api/serializers/voucher.py

@@ -19,6 +19,8 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
+from decimal import Decimal
+
 from rest_framework import serializers
 from rest_framework.exceptions import ValidationError
 
@@ -64,14 +66,15 @@ class SeatGuidField(serializers.CharField):
 
 class VoucherSerializer(I18nAwareModelSerializer):
     seat = SeatGuidField(allow_null=True, required=False)
+    budget_used = serializers.DecimalField(read_only=True, max_digits=13, decimal_places=2, min_value=Decimal('0.00'))
 
     class Meta:
         model = Voucher
-        fields = ('id', 'code', 'max_usages', 'redeemed', 'min_usages', 'valid_until', 'block_quota',
+        fields = ('id', 'created', 'code', 'max_usages', 'redeemed', 'min_usages', 'valid_until', 'block_quota',
                   'allow_ignore_quota', 'price_mode', 'value', 'item', 'variation', 'quota',
                   'tag', 'comment', 'subevent', 'show_hidden_items', 'seat', 'all_addons_included',
-                  'all_bundles_included')
-        read_only_fields = ('id', 'redeemed')
+                  'all_bundles_included', 'budget', 'budget_used')
+        read_only_fields = ('id', 'redeemed', 'budget_used')
         list_serializer_class = VoucherListSerializer
 
     def validate(self, data):

src/pretix/api/signals.py

@@ -21,22 +21,22 @@
 #
 from datetime import timedelta
 
-from django.dispatch import Signal, receiver
+from django.dispatch import receiver
 from django.utils.timezone import now
 from django_scopes import scopes_disabled
 
 from pretix.api.models import ApiCall, WebHookCall
-from pretix.base.signals import EventPluginSignal, periodic_task
+from pretix.base.signals import EventPluginSignal, GlobalSignal, periodic_task
 from pretix.helpers.periodic import minimum_interval
 
-register_webhook_events = Signal()
+register_webhook_events = GlobalSignal()
 """
 This signal is sent out to get all known webhook events. Receivers should return an
 instance of a subclass of ``pretix.api.webhooks.WebhookEvent`` or a list of such
 instances.
 """
 
-register_device_security_profile = Signal()
+register_device_security_profile = GlobalSignal()
 """
 This signal is sent out to get all known device security_profiles. Receivers should
 return an instance of a subclass of ``pretix.api.auth.devicesecurity.BaseSecurityProfile``

src/pretix/api/urls.py

@@ -66,6 +66,7 @@ orga_router.register(r'orders', order.OrganizerOrderViewSet)
 orga_router.register(r'invoices', order.InvoiceViewSet)
 orga_router.register(r'scheduled_exports', exporters.ScheduledOrganizerExportViewSet)
 orga_router.register(r'exporters', exporters.OrganizerExportersViewSet, basename='exporters')
+orga_router.register(r'transactions', order.OrganizerTransactionViewSet)
 
 team_router = routers.DefaultRouter()
 team_router.register(r'members', organizer.TeamMemberViewSet)
@@ -83,6 +84,7 @@ event_router.register(r'quotas', item.QuotaViewSet)
 event_router.register(r'vouchers', voucher.VoucherViewSet)
 event_router.register(r'orders', order.EventOrderViewSet)
 event_router.register(r'orderpositions', order.OrderPositionViewSet)
+event_router.register(r'transactions', order.TransactionViewSet)
 event_router.register(r'invoices', order.InvoiceViewSet)
 event_router.register(r'revokedsecrets', order.RevokedSecretViewSet, basename='revokedsecrets')
 event_router.register(r'blockedsecrets', order.BlockedSecretViewSet, basename='blockedsecrets')
@@ -130,6 +132,8 @@ urlpatterns = [
             name="checkinrpc.redeem"),
     re_path(r'^organizers/(?P<organizer>[^/]+)/checkinrpc/search/$', checkin.CheckinRPCSearchView.as_view(),
             name="checkinrpc.search"),
+    re_path(r'^organizers/(?P<organizer>[^/]+)/checkinrpc/annul/$', checkin.CheckinRPCAnnulView.as_view(),
+            name="checkinrpc.annul"),
     re_path(r'^organizers/(?P<organizer>[^/]+)/settings/$', organizer.OrganizerSettingsView.as_view(),
             name="organizer.settings"),
     re_path(r'^organizers/(?P<organizer>[^/]+)/giftcards/(?P<giftcard>[^/]+)/', include(giftcard_router.urls)),

src/pretix/api/views/checkin.py

@@ -20,12 +20,13 @@
 # <https://www.gnu.org/licenses/>.
 #
 import operator
+from datetime import timedelta
 from functools import reduce
 
 import django_filters
 from django.conf import settings
 from django.core.exceptions import ValidationError as BaseValidationError
-from django.db import transaction
+from django.db import connection, transaction
 from django.db.models import (
     Count, Exists, F, Max, OrderBy, OuterRef, Prefetch, Q, Subquery,
     prefetch_related_objects,
@@ -39,17 +40,19 @@ from django.utils.translation import gettext
 from django_filters.rest_framework import DjangoFilterBackend, FilterSet
 from django_scopes import scopes_disabled
 from packaging.version import parse
-from rest_framework import views, viewsets
+from rest_framework import status, views, viewsets
 from rest_framework.decorators import action
-from rest_framework.exceptions import PermissionDenied, ValidationError
+from rest_framework.exceptions import (
+    NotFound, PermissionDenied, ValidationError,
+)
 from rest_framework.fields import DateTimeField
 from rest_framework.generics import ListAPIView
 from rest_framework.permissions import SAFE_METHODS
 from rest_framework.response import Response
 
 from pretix.api.serializers.checkin import (
-    CheckinListSerializer, CheckinRPCRedeemInputSerializer,
-    MiniCheckinListSerializer,
+    CheckinListSerializer, CheckinRPCAnnulInputSerializer,
+    CheckinRPCRedeemInputSerializer, MiniCheckinListSerializer,
 )
 from pretix.api.serializers.item import QuestionSerializer
 from pretix.api.serializers.order import (
@@ -66,6 +69,8 @@ from pretix.base.models.orders import PrintLog
 from pretix.base.services.checkin import (
     CheckInError, RequiredQuestionsError, SQLLogic, perform_checkin,
 )
+from pretix.base.signals import checkin_annulled
+from pretix.helpers import OF_SELF
 
 with scopes_disabled():
     class CheckinListFilter(FilterSet):
@@ -813,7 +818,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
         ctx = super().get_serializer_context()
         ctx['event'] = self.request.event
         ctx['expand'] = self.request.query_params.getlist('expand')
-        ctx['pdf_data'] = self.request.query_params.get('pdf_data', 'false') == 'true'
+        ctx['pdf_data'] = self.request.query_params.get('pdf_data', 'false').lower() == 'true'
         return ctx
 
     def get_filterset_kwargs(self):
@@ -832,9 +837,9 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
     def get_queryset(self, ignore_status=False, ignore_products=False):
         qs = _checkin_list_position_queryset(
             [self.checkinlist],
-            ignore_status=self.request.query_params.get('ignore_status', 'false') == 'true' or ignore_status,
+            ignore_status=self.request.query_params.get('ignore_status', 'false').lower() == 'true' or ignore_status,
             ignore_products=ignore_products,
-            pdf_data=self.request.query_params.get('pdf_data', 'false') == 'true',
+            pdf_data=self.request.query_params.get('pdf_data', 'false').lower() == 'true',
             expand=self.request.query_params.getlist('expand'),
         )
 
@@ -876,7 +881,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
             user=self.request.user,
             auth=self.request.auth,
             expand=self.request.query_params.getlist('expand'),
-            pdf_data=self.request.query_params.get('pdf_data', 'false') == 'true',
+            pdf_data=self.request.query_params.get('pdf_data', 'false').lower() == 'true',
             questions_supported=self.request.data.get('questions_supported', True),
             canceled_supported=self.request.data.get('canceled_supported', False),
             request=self.request,  # this is not clean, but we need it in the serializers for URL generation
@@ -911,7 +916,7 @@ class CheckinRPCRedeemView(views.APIView):
             user=self.request.user,
             auth=self.request.auth,
             expand=self.request.query_params.getlist('expand'),
-            pdf_data=self.request.query_params.get('pdf_data', 'false') == 'true',
+            pdf_data=self.request.query_params.get('pdf_data', 'false').lower() == 'true',
             questions_supported=s.validated_data['questions_supported'],
             use_order_locale=s.validated_data['use_order_locale'],
             canceled_supported=True,
@@ -989,9 +994,9 @@ class CheckinRPCSearchView(ListAPIView):
     def get_queryset(self, ignore_status=False, ignore_products=False):
         qs = _checkin_list_position_queryset(
             self.lists,
-            ignore_status=self.request.query_params.get('ignore_status', 'false') == 'true' or ignore_status,
+            ignore_status=self.request.query_params.get('ignore_status', 'false').lower() == 'true' or ignore_status,
             ignore_products=ignore_products,
-            pdf_data=self.request.query_params.get('pdf_data', 'false') == 'true',
+            pdf_data=self.request.query_params.get('pdf_data', 'false').lower() == 'true',
             expand=self.request.query_params.getlist('expand'),
         )
 
@@ -999,3 +1004,79 @@ class CheckinRPCSearchView(ListAPIView):
             qs = qs.none()
 
         return qs
+
+
+class CheckinRPCAnnulView(views.APIView):
+    def post(self, request, *args, **kwargs):
+        if isinstance(self.request.auth, (TeamAPIToken, Device)):
+            events = self.request.auth.get_events_with_permission(('can_change_orders', 'can_checkin_orders'))
+        elif self.request.user.is_authenticated:
+            events = self.request.user.get_events_with_permission(('can_change_orders', 'can_checkin_orders'), self.request).filter(
+                organizer=self.request.organizer
+            )
+        else:
+            raise ValueError("unknown authentication method")
+
+        s = CheckinRPCAnnulInputSerializer(data=request.data, context={'events': events})
+        s.is_valid(raise_exception=True)
+
+        with transaction.atomic():
+            try:
+                qs = Checkin.all.all()
+                if isinstance(request.auth, Device):
+                    qs = qs.filter(device=request.auth)
+                ci = qs.select_for_update(
+                    of=OF_SELF,
+                ).select_related("position", "position__order", "position__order__event").get(
+                    list__in=s.validated_data['lists'],
+                    nonce=s.validated_data['nonce'],
+                )
+                if connection.features.has_select_for_update_of and ci.position_id:
+                    # Lock position as well, can't do it with of= above because relation is nullable
+                    OrderPosition.objects.select_for_update(of=OF_SELF).get(pk=ci.position_id)
+
+                if not ci.successful or not ci.position:
+                    raise ValidationError("Cannot annul an unsuccessful checkin")
+            except Checkin.DoesNotExist:
+                raise NotFound("No check-in found based on nonce")
+            except Checkin.MultipleObjectsReturned:
+                raise ValidationError("Multiple check-ins found based on nonce")
+
+            annulment_time = s.validated_data.get("datetime") or now()
+
+            if annulment_time - ci.datetime > timedelta(minutes=15):
+                # Compare to sent datetime, which makes this cheatable, but allows offline annulment of checkins
+                ci.position.order.log_action('pretix.event.checkin.annulment.ignored', data={
+                    'checkin': ci.pk,
+                    'position': ci.position.id,
+                    'positionid': ci.position.positionid,
+                    'datetime': annulment_time,
+                    'error_explanation': s.validated_data.get("error_explanation"),
+                    'type': ci.type,
+                    'list': ci.list_id,
+                }, user=request.user, auth=request.auth)
+                return Response({
+                    "non_field_errors": ["Annulment is not allowed more than 15 minutes after check-in"]
+                }, status=status.HTTP_400_BAD_REQUEST)
+
+            if ci.device and ci.device != request.auth:
+                return Response({
+                    "non_field_errors": ["Annulment is only allowed from the same device"]
+                }, status=status.HTTP_400_BAD_REQUEST)
+
+            ci.successful = False
+            ci.error_reason = Checkin.REASON_ANNULLED
+            ci.error_explanation = s.validated_data.get("error_explanation")
+            ci.save(update_fields=["successful", "error_reason", "error_explanation"])
+            ci.position.order.log_action('pretix.event.checkin.annulled', data={
+                'checkin': ci.pk,
+                'position': ci.position.id,
+                'positionid': ci.position.positionid,
+                'datetime': annulment_time,
+                'error_explanation': s.validated_data.get("error_explanation"),
+                'type': ci.type,
+                'list': ci.list_id,
+            }, user=request.user, auth=request.auth)
+            checkin_annulled.send(ci.position.order.event, checkin=ci)
+
+        return Response({"status": "ok"}, status=status.HTTP_200_OK)

src/pretix/api/views/event.py

@@ -580,6 +580,11 @@ class TaxRuleViewSet(ConditionalListView, viewsets.ModelViewSet):
         )
         super().perform_destroy(instance)
 
+    def get_serializer_context(self):
+        ctx = super().get_serializer_context()
+        ctx["event"] = self.request.event
+        return ctx
+
 
 class ItemMetaPropertiesViewSet(viewsets.ModelViewSet):
     serializer_class = ItemMetaPropertiesSerializer

src/pretix/api/views/item.py

@@ -121,7 +121,6 @@ class ItemViewSet(ConditionalListView, viewsets.ModelViewSet):
     def get_serializer_context(self):
         ctx = super().get_serializer_context()
         ctx['event'] = self.request.event
-        ctx['request'] = self.request
         return ctx
 
     def perform_update(self, serializer):

src/pretix/api/views/order.py

@@ -57,9 +57,9 @@ from pretix.api.serializers.order import (
     BlockedTicketSecretSerializer, InvoiceSerializer, OrderCreateSerializer,
     OrderPaymentCreateSerializer, OrderPaymentSerializer,
     OrderPositionSerializer, OrderRefundCreateSerializer,
-    OrderRefundSerializer, OrderSerializer, PriceCalcSerializer,
-    PrintLogSerializer, RevokedTicketSecretSerializer,
-    SimulatedOrderSerializer,
+    OrderRefundSerializer, OrderSerializer, OrganizerTransactionSerializer,
+    PriceCalcSerializer, PrintLogSerializer, RevokedTicketSecretSerializer,
+    SimulatedOrderSerializer, TransactionSerializer,
 )
 from pretix.api.serializers.orderchange import (
     BlockNameSerializer, OrderChangeOperationSerializer,
@@ -80,6 +80,7 @@ from pretix.base.models import (
 )
 from pretix.base.models.orders import (
     BlockedTicketSecret, PrintLog, QuestionAnswer, RevokedTicketSecret,
+    Transaction,
 )
 from pretix.base.payment import PaymentException
 from pretix.base.pdf import get_images
@@ -87,7 +88,7 @@ from pretix.base.secrets import assign_ticket_secret
 from pretix.base.services import tickets
 from pretix.base.services.invoices import (
     generate_cancellation, generate_invoice, invoice_pdf, invoice_qualified,
-    regenerate_invoice,
+    regenerate_invoice, transmit_invoice,
 )
 from pretix.base.services.mail import SendMailException
 from pretix.base.services.orders import (
@@ -227,7 +228,7 @@ class OrderViewSetMixin:
     def get_queryset(self):
         qs = self.get_base_queryset()
         if 'fees' not in self.request.GET.getlist('exclude'):
-            if self.request.query_params.get('include_canceled_fees', 'false') == 'true':
+            if self.request.query_params.get('include_canceled_fees', 'false').lower() == 'true':
                 fqs = OrderFee.all
             else:
                 fqs = OrderFee.objects
@@ -245,11 +246,11 @@ class OrderViewSetMixin:
         return qs
 
     def _positions_prefetch(self, request):
-        if request.query_params.get('include_canceled_positions', 'false') == 'true':
+        if request.query_params.get('include_canceled_positions', 'false').lower() == 'true':
             opq = OrderPosition.all
         else:
             opq = OrderPosition.objects
-        if request.query_params.get('pdf_data', 'false') == 'true' and getattr(request, 'event', None):
+        if request.query_params.get('pdf_data', 'false').lower() == 'true' and getattr(request, 'event', None):
             prefetch_related_objects([request.organizer], 'meta_properties')
             prefetch_related_objects(
                 [request.event],
@@ -343,7 +344,7 @@ class EventOrderViewSet(OrderViewSetMixin, viewsets.ModelViewSet):
     def get_serializer_context(self):
         ctx = super().get_serializer_context()
         ctx['event'] = self.request.event
-        ctx['pdf_data'] = self.request.query_params.get('pdf_data', 'false') == 'true'
+        ctx['pdf_data'] = self.request.query_params.get('pdf_data', 'false').lower() == 'true'
         return ctx
 
     def get_base_queryset(self):
@@ -942,6 +943,7 @@ class EventOrderViewSet(OrderViewSetMixin, viewsets.ModelViewSet):
     @action(detail=True, methods=['POST'])
     def change(self, request, **kwargs):
         order = self.get_object()
+        check_quotas = self.request.query_params.get('check_quotas', 'true').lower() == 'true'
 
         serializer = OrderChangeOperationSerializer(
             context={'order': order, **self.get_serializer_context()},
@@ -1007,7 +1009,7 @@ class EventOrderViewSet(OrderViewSetMixin, viewsets.ModelViewSet):
             elif serializer.validated_data.get('recalculate_taxes') == 'keep_gross':
                 ocm.recalculate_taxes(keep='gross')
 
-            ocm.commit()
+            ocm.commit(check_quotas=check_quotas)
         except OrderError as e:
             raise ValidationError(str(e))
 
@@ -1085,17 +1087,18 @@ class OrderPositionViewSet(viewsets.ModelViewSet):
     def get_serializer_context(self):
         ctx = super().get_serializer_context()
         ctx['event'] = self.request.event
-        ctx['pdf_data'] = self.request.query_params.get('pdf_data', 'false') == 'true'
+        ctx['pdf_data'] = self.request.query_params.get('pdf_data', 'false').lower() == 'true'
+        ctx['check_quotas'] = self.request.query_params.get('check_quotas', 'true').lower() == 'true'
         return ctx
 
     def get_queryset(self):
-        if self.request.query_params.get('include_canceled_positions', 'false') == 'true':
+        if self.request.query_params.get('include_canceled_positions', 'false').lower() == 'true':
             qs = OrderPosition.all
         else:
             qs = OrderPosition.objects
 
         qs = qs.filter(order__event=self.request.event)
-        if self.request.query_params.get('pdf_data', 'false') == 'true':
+        if self.request.query_params.get('pdf_data', 'false').lower() == 'true':
             prefetch_related_objects([self.request.organizer], 'meta_properties')
             prefetch_related_objects(
                 [self.request.event],
@@ -1888,6 +1891,12 @@ class RetryException(APIException):
     default_code = 'retry_later'
 
 
+class CurrentlyInflightException(APIException):
+    status_code = 409
+    default_detail = 'The requested action is already in progress.'
+    default_code = 'currently_inflight'
+
+
 class InvoiceViewSet(viewsets.ReadOnlyModelViewSet):
     serializer_class = InvoiceSerializer
     queryset = Invoice.objects.none()
@@ -1936,13 +1945,52 @@ class InvoiceViewSet(viewsets.ReadOnlyModelViewSet):
         resp['Content-Disposition'] = 'attachment; filename="{}.pdf"'.format(invoice.number)
         return resp
 
+    @action(detail=True, methods=['POST'])
+    def transmit(self, request, **kwargs):
+        invoice = self.get_object()
+        if invoice.shredded:
+            raise PermissionDenied('The invoice file is no longer stored on the server.')
+
+        if invoice.transmission_status != Invoice.TRANSMISSION_STATUS_PENDING:
+            raise PermissionDenied('The invoice is not in pending state.')
+
+        transmit_invoice.apply_async(args=(self.request.event.pk, invoice.pk, False))
+        return Response(status=204)
+
+    @action(detail=True, methods=['POST'])
+    def retransmit(self, request, **kwargs):
+        invoice = self.get_object()
+        if invoice.shredded:
+            raise PermissionDenied('The invoice file is no longer stored on the server.')
+
+        with transaction.atomic(durable=True):
+            invoice = Invoice.objects.select_for_update(of=OF_SELF).get(pk=invoice.pk)
+
+            if invoice.transmission_status == Invoice.TRANSMISSION_STATUS_INFLIGHT:
+                raise CurrentlyInflightException()
+
+            invoice.transmission_status = Invoice.TRANSMISSION_STATUS_PENDING
+            invoice.transmission_date = now()
+            invoice.save(update_fields=["transmission_status", "transmission_date"])
+            invoice.order.log_action(
+                'pretix.event.order.invoice.retransmitted',
+                user=self.request.user,
+                auth=self.request.auth,
+                data={
+                    'invoice': invoice.pk,
+                    'full_invoice_no': invoice.full_invoice_no,
+                }
+            )
+        transmit_invoice.apply_async(args=(self.request.event.pk, invoice.pk, True))
+        return Response(status=204)
+
     @action(detail=True, methods=['POST'])
     def regenerate(self, request, **kwargs):
         inv = self.get_object()
         if inv.canceled:
             raise ValidationError('The invoice has already been canceled.')
-        if not inv.event.settings.invoice_regenerate_allowed:
-            raise PermissionDenied('Invoices may not be changed after they are created.')
+        if not inv.regenerate_allowed:
+            raise PermissionDenied('Invoice may not be regenerated.')
         elif inv.shredded:
             raise PermissionDenied('The invoice file is no longer stored on the server.')
         elif inv.sent_to_organizer:
@@ -2030,3 +2078,61 @@ class BlockedSecretViewSet(viewsets.ReadOnlyModelViewSet):
 
     def get_queryset(self):
         return BlockedTicketSecret.objects.filter(event=self.request.event)
+
+
+with scopes_disabled():
+    class TransactionFilter(FilterSet):
+        order = django_filters.CharFilter(field_name='order', lookup_expr='code__iexact')
+        event = django_filters.CharFilter(field_name='order__event', lookup_expr='slug__iexact')
+        datetime_since = django_filters.IsoDateTimeFilter(field_name='datetime', lookup_expr='gte')
+        datetime_before = django_filters.IsoDateTimeFilter(field_name='datetime', lookup_expr='lt')
+        created_since = django_filters.IsoDateTimeFilter(field_name='created', lookup_expr='gte')
+        created_before = django_filters.IsoDateTimeFilter(field_name='created', lookup_expr='lt')
+
+        class Meta:
+            model = Transaction
+            fields = {
+                'item': ['exact', 'in'],
+                'variation': ['exact', 'in'],
+                'subevent': ['exact', 'in'],
+                'tax_rule': ['exact', 'in'],
+                'tax_code': ['exact', 'in'],
+                'tax_rate': ['exact', 'in'],
+                'fee_type': ['exact', 'in'],
+            }
+
+
+class TransactionViewSet(viewsets.ReadOnlyModelViewSet):
+    serializer_class = TransactionSerializer
+    queryset = Transaction.objects.none()
+    filter_backends = (DjangoFilterBackend, TotalOrderingFilter)
+    ordering = ('datetime', 'pk')
+    ordering_fields = ('datetime', 'created', 'id',)
+    filterset_class = TransactionFilter
+    permission = 'can_view_orders'
+
+    def get_queryset(self):
+        return Transaction.objects.filter(order__event=self.request.event).select_related("order")
+
+
+class OrganizerTransactionViewSet(TransactionViewSet):
+    serializer_class = OrganizerTransactionSerializer
+    permission = None
+
+    def get_queryset(self):
+        qs = Transaction.objects.filter(
+            order__event__organizer=self.request.organizer
+        ).select_related("order", "order__event")
+
+        if isinstance(self.request.auth, (TeamAPIToken, Device)):
+            qs = qs.filter(
+                order__event__in=self.request.auth.get_events_with_permission("can_view_orders"),
+            )
+        elif self.request.user.is_authenticated:
+            qs = qs.filter(
+                order__event__in=self.request.user.get_events_with_permission("can_view_orders", request=self.request)
+            )
+        else:
+            raise PermissionDenied("Unknown authentication scheme")
+
+        return qs

src/pretix/api/views/organizer.py

@@ -19,7 +19,9 @@
 # You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 #
+import operator
 from decimal import Decimal
+from functools import reduce
 
 import django_filters
 from django.contrib.auth.hashers import make_password
@@ -48,15 +50,18 @@ from pretix.api.serializers.organizer import (
     TeamInviteSerializer, TeamMemberSerializer, TeamSerializer,
 )
 from pretix.base.models import (
-    Customer, Device, GiftCard, GiftCardTransaction, Membership,
-    MembershipType, Organizer, SalesChannel, SeatingPlan, Team, TeamAPIToken,
-    TeamInvite, User,
+    Customer, Device, Event, GiftCard, GiftCardTransaction, LogEntry,
+    Membership, MembershipType, Organizer, SalesChannel, SeatingPlan, Team,
+    TeamAPIToken, TeamInvite, User,
+)
+from pretix.base.plugins import (
+    PLUGIN_LEVEL_EVENT, PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID,
 )
 from pretix.helpers import OF_SELF
 from pretix.helpers.dicts import merge_dicts
 
 
-class OrganizerViewSet(viewsets.ReadOnlyModelViewSet):
+class OrganizerViewSet(mixins.UpdateModelMixin, viewsets.ReadOnlyModelViewSet):
     serializer_class = OrganizerSerializer
     queryset = Organizer.objects.none()
     lookup_field = 'slug'
@@ -65,6 +70,7 @@ class OrganizerViewSet(viewsets.ReadOnlyModelViewSet):
     filter_backends = (TotalOrderingFilter,)
     ordering = ('slug',)
     ordering_fields = ('name', 'slug')
+    write_permission = "can_change_organizer_settings"
 
     def get_queryset(self):
         if self.request.user.is_authenticated:
@@ -83,6 +89,67 @@ class OrganizerViewSet(viewsets.ReadOnlyModelViewSet):
         else:
             return Organizer.objects.filter(pk=self.request.auth.team.organizer_id)
 
+    @transaction.atomic()
+    def perform_update(self, serializer):
+        from pretix.base.plugins import get_all_plugins
+
+        original_data = self.get_serializer(instance=serializer.instance).data
+
+        current_plugins_value = serializer.instance.get_plugins()
+        updated_plugins_value = serializer.validated_data.get('plugins', None)
+
+        super().perform_update(serializer)
+
+        if serializer.data == original_data:
+            # Performance optimization: If nothing was changed, we do not need to save or log anything.
+            # This costs us a few cycles on save, but avoids thousands of lines in our log.
+            return
+
+        if updated_plugins_value is not None and set(updated_plugins_value) != set(current_plugins_value):
+            enabled = {m: 'enabled' for m in updated_plugins_value if m not in current_plugins_value}
+            disabled = {m: 'disabled' for m in current_plugins_value if m not in updated_plugins_value}
+            changed = merge_dicts(enabled, disabled)
+
+            plugins_available = {
+                p.module: p
+                for p in get_all_plugins(organizer=serializer.instance)
+                if not p.name.startswith('.') and getattr(p, 'visible', True)
+            }
+            qs = []
+            for module in disabled:
+                pluginmeta = plugins_available[module]
+                level = getattr(pluginmeta, 'level', PLUGIN_LEVEL_EVENT)
+                if level == PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID:
+                    qs.append(Q(plugins__regex='(^|,)' + module + '(,|$)'))
+
+            if qs:
+                events_to_disable = set(self.request.organizer.events.filter(
+                    reduce(operator.or_, qs)
+                ).values_list("pk", flat=True))
+                logentries_to_save = []
+                events_to_save = []
+
+                for e in self.request.organizer.events.filter(pk__in=events_to_disable):
+                    for module in disabled:
+                        if module in e.get_plugins():
+                            logentries_to_save.append(
+                                e.log_action('pretix.event.plugins.disabled', user=self.request.user, auth=self.request.auth,
+                                             data={'plugin': module}, save=False)
+                            )
+                            e.disable_plugin(module)
+                            events_to_save.append(e)
+
+                Event.objects.bulk_update(events_to_save, fields=["plugins"])
+                LogEntry.objects.bulk_create(logentries_to_save)
+
+            for module, operation in changed.items():
+                serializer.instance.log_action(
+                    'pretix.organizer.plugins.' + operation,
+                    user=self.request.user,
+                    auth=self.request.auth,
+                    data={'plugin': module}
+                )
+
 
 class SeatingPlanViewSet(viewsets.ModelViewSet):
     serializer_class = SeatingPlanSerializer
@@ -479,7 +546,8 @@ class DeviceViewSet(mixins.CreateModelMixin,
 
 
 class OrganizerSettingsView(views.APIView):
-    permission = 'can_change_organizer_settings'
+    permission = None
+    write_permission = 'can_change_organizer_settings'
 
     def get(self, request, *args, **kwargs):
         s = OrganizerSettingsSerializer(instance=request.organizer.settings, organizer=request.organizer, context={

src/pretix/api/webhooks.py

@@ -78,6 +78,13 @@ class WebhookEvent:
         """
         raise NotImplementedError()  # NOQA
 
+    @property
+    def help_text(self) -> str:
+        """
+        A human-readable description
+        """
+        return ""
+
 
 def get_all_webhook_events():
     global _ALL_EVENTS
@@ -97,9 +104,10 @@ def get_all_webhook_events():
 
 
 class ParametrizedWebhookEvent(WebhookEvent):
-    def __init__(self, action_type, verbose_name):
+    def __init__(self, action_type, verbose_name, help_text=""):
         self._action_type = action_type
         self._verbose_name = verbose_name
+        self._help_text = help_text
         super().__init__()
 
     @property
@@ -110,6 +118,10 @@ class ParametrizedWebhookEvent(WebhookEvent):
     def verbose_name(self):
         return self._verbose_name
 
+    @property
+    def help_text(self):
+        return self._help_text
+
 
 class ParametrizedOrderWebhookEvent(ParametrizedWebhookEvent):
     def build_payload(self, logentry: LogEntry):
@@ -161,6 +173,19 @@ class ParametrizedEventWebhookEvent(ParametrizedWebhookEvent):
         }
 
 
+class ParametrizedVoucherWebhookEvent(ParametrizedWebhookEvent):
+
+    def build_payload(self, logentry: LogEntry):
+        # do not use content_object, this is also called in deletion
+        return {
+            'notification_id': logentry.pk,
+            'organizer': logentry.event.organizer.slug,
+            'event': logentry.event.slug,
+            'voucher': logentry.object_id,
+            'action': logentry.action_type,
+        }
+
+
 class ParametrizedSubEventWebhookEvent(ParametrizedWebhookEvent):
 
     def build_payload(self, logentry: LogEntry):
@@ -346,8 +371,9 @@ def register_default_webhook_events(sender, **kwargs):
         ),
         ParametrizedItemWebhookEvent(
             'pretix.event.item.*',
-            _('Product changed (including product added or deleted and including changes to nested objects like '
-              'variations or bundles)'),
+            _('Product changed'),
+            _('This includes product added or deleted and changes to nested objects like '
+              'variations or bundles.'),
         ),
         ParametrizedEventWebhookEvent(
             'pretix.event.live.activated',
@@ -381,6 +407,19 @@ def register_default_webhook_events(sender, **kwargs):
             'pretix.event.orders.waitinglist.voucher_assigned',
             _('Waiting list entry received voucher'),
         ),
+        ParametrizedVoucherWebhookEvent(
+            'pretix.voucher.added',
+            _('Voucher added'),
+        ),
+        ParametrizedVoucherWebhookEvent(
+            'pretix.voucher.changed',
+            _('Voucher changed'),
+            _('Only includes explicit changes to the voucher, not e.g. an increase of the number of redemptions.')
+        ),
+        ParametrizedVoucherWebhookEvent(
+            'pretix.voucher.deleted',
+            _('Voucher deleted'),
+        ),
         ParametrizedCustomerWebhookEvent(
             'pretix.customer.created',
             _('Customer account created'),
@@ -476,7 +515,7 @@ def send_webhook(self, logentry_id: int, action_type: str, webhook_id: int, retr
         300,  # + 5 minutes
         1200,  # + 20 minutes
         3600,  # + 60 minutes
-        1440,  # + 4 hours
+        14400,  # + 4 hours
         21600,  # + 6 hours
         43200,  # + 12 hours
         43200,  # + 24 hours
@@ -527,8 +566,10 @@ def send_webhook(self, logentry_id: int, action_type: str, webhook_id: int, retr
                 if retry_count >= len(retry_intervals):
                     return 'retry-given-up'
                 elif retry_intervals[retry_count] < retry_celery_cutoff:
-                    send_webhook.apply_async(args=(logentry_id, action_type, webhook_id, retry_count + 1),
-                                             countdown=retry_intervals[retry_count])
+                    send_webhook.apply_async(
+                        args=(logentry_id, action_type, webhook_id, retry_count + 1),
+                        countdown=retry_intervals[retry_count]
+                    )
                     return 'retry-via-celery'
                 else:
                     webhook.retries.update_or_create(
@@ -555,7 +596,10 @@ def send_webhook(self, logentry_id: int, action_type: str, webhook_id: int, retr
             if retry_count >= len(retry_intervals):
                 return 'retry-given-up'
             elif retry_intervals[retry_count] < retry_celery_cutoff:
-                send_webhook.apply_async(args=(logentry_id, action_type, webhook_id, retry_count + 1))
+                send_webhook.apply_async(
+                    args=(logentry_id, action_type, webhook_id, retry_count + 1),
+                    countdown=retry_intervals[retry_count]
+                )
                 return 'retry-via-celery'
             else:
                 webhook.retries.update_or_create(

src/pretix/base/apps.py

@@ -43,10 +43,10 @@ class PretixBaseConfig(AppConfig):
         from . import exporter  # NOQA
         from . import payment  # NOQA
         from . import exporters  # NOQA
-        from . import invoice  # NOQA
+        from .invoicing import pdf, transmission, email, peppol, national  # NOQA
         from . import notifications  # NOQA
         from . import email  # NOQA
-        from .services import auth, checkin, currencies, export, mail, tickets, cart, modelimport, orders, invoices, cleanup, update_check, quotas, notifications, vouchers  # NOQA
+        from .services import auth, checkin, currencies, datasync, export, mail, tickets, cart, modelimport, orders, invoices, cleanup, update_check, quotas, notifications, vouchers  # NOQA
         from .models import _transactions  # NOQA
         from django.conf import settings
 

src/pretix/base/customersso/oidc.py

@@ -199,6 +199,7 @@ def oidc_validate_authorization(provider, code, redirect_uri, pkce_code_verifier
         params['client_id'] = provider.configuration['client_id']
         params['client_secret'] = provider.configuration['client_secret']
 
+    resp = None
     try:
         resp = requests.post(
             endpoint,
@@ -214,7 +215,10 @@ def oidc_validate_authorization(provider, code, redirect_uri, pkce_code_verifier
         resp.raise_for_status()
         data = resp.json()
     except RequestException:
-        logger.exception('Could not retrieve authorization token')
+        if resp:
+            logger.exception(f'Could not retrieve authorization token. Response: {resp.text}')
+        else:
+            logger.exception('Could not retrieve authorization token')
         raise ValidationError(
             _('Login was not successful. Error message: "{error}".').format(
                 error='could not reach login provider',
@@ -222,6 +226,7 @@ def oidc_validate_authorization(provider, code, redirect_uri, pkce_code_verifier
         )
 
     if 'access_token' not in data:
+        logger.error(f'Could not find access token. Response: {data}')
         raise ValidationError(
             _('Login was not successful. Error message: "{error}".').format(
                 error='access token missing',
@@ -229,6 +234,7 @@ def oidc_validate_authorization(provider, code, redirect_uri, pkce_code_verifier
         )
 
     endpoint = provider.configuration['provider_config']['userinfo_endpoint']
+    resp = None
     try:
         # https://openid.net/specs/openid-connect-core-1_0.html#UserInfo
         resp = requests.get(
@@ -240,7 +246,10 @@ def oidc_validate_authorization(provider, code, redirect_uri, pkce_code_verifier
         resp.raise_for_status()
         userinfo = resp.json()
     except RequestException:
-        logger.exception('Could not retrieve user info')
+        if resp:
+            logger.exception(f'Could not retrieve user info. Response: {resp.text}')
+        else:
+            logger.exception('Could not retrieve user info')
         raise ValidationError(
             _('Login was not successful. Error message: "{error}".').format(
                 error='could not fetch user info',

src/pretix/base/datasync/__init__.py

@@ -0,0 +1,21 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#

src/pretix/base/datasync/datasync.py

@@ -0,0 +1,442 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+import json
+import logging
+from collections import namedtuple
+from datetime import timedelta
+from functools import cached_property
+from typing import List, Optional, Protocol
+
+import sentry_sdk
+from django.db import DatabaseError, transaction
+from django.utils.timezone import now
+from django.utils.translation import gettext_lazy as _
+
+from pretix.base.datasync.sourcefields import (
+    EVENT, EVENT_OR_SUBEVENT, ORDER, ORDER_POSITION, get_data_fields,
+)
+from pretix.base.i18n import language
+from pretix.base.logentrytype_registry import make_link
+from pretix.base.models.datasync import OrderSyncQueue, OrderSyncResult
+from pretix.base.signals import PluginAwareRegistry
+from pretix.helpers import OF_SELF
+
+logger = logging.getLogger(__name__)
+
+
+datasync_providers = PluginAwareRegistry({"identifier": lambda o: o.identifier})
+
+
+class BaseSyncError(Exception):
+    def __init__(self, messages, full_message=None):
+        self.messages = messages
+        self.full_message = full_message
+
+
+class UnrecoverableSyncError(BaseSyncError):
+    """
+    A SyncProvider encountered a permanent problem, where a retry will not be successful.
+    """
+    failure_mode = "permanent"
+
+
+class SyncConfigError(UnrecoverableSyncError):
+    """
+    A SyncProvider is misconfigured in a way where a retry without configuration change will
+    not be successful.
+    """
+    failure_mode = "config"
+
+
+class RecoverableSyncError(BaseSyncError):
+    """
+    A SyncProvider has encountered a temporary problem, and the sync should be retried
+    at a later time.
+    """
+    pass
+
+
+class ObjectMapping(Protocol):
+    id: int
+    pretix_model: str
+    external_object_type: str
+    pretix_id_field: str
+    external_id_field: str
+    property_mappings: str
+
+
+StaticMapping = namedtuple('StaticMapping', ('id', 'pretix_model', 'external_object_type', 'pretix_id_field', 'external_id_field', 'property_mappings'))
+
+
+class OutboundSyncProvider:
+    max_attempts = 5
+
+    def __init__(self, event):
+        self.event = event
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+
+    @classmethod
+    @property
+    def display_name(cls):
+        return str(cls.identifier)
+
+    @classmethod
+    def enqueue_order(cls, order, triggered_by, not_before=None):
+        """
+        Adds an order to the sync queue. May only be called on derived classes which define an ``identifier`` attribute.
+
+        Should be called in the appropriate signal receivers, e.g.::
+
+            @receiver(order_placed, dispatch_uid="mysync_order_placed")
+            def on_order_placed(sender, order, **kwargs):
+                MySyncProvider.enqueue_order(order, "order_placed")
+
+        :param order: the Order that should be synced
+        :param triggered_by: the reason why the order should be synced, e.g. name of the signal
+                             (currently only used internally for logging)
+        """
+        if not hasattr(cls, 'identifier'):
+            raise TypeError('Call this method on a derived class that defines an "identifier" attribute.')
+        OrderSyncQueue.objects.update_or_create(
+            order=order,
+            sync_provider=cls.identifier,
+            in_flight=False,
+            defaults={
+                "event": order.event,
+                "triggered_by": triggered_by,
+                "not_before": not_before or now(),
+                "need_manual_retry": None,
+            },
+        )
+
+    @classmethod
+    def get_external_link_info(cls, event, external_link_href, external_link_display_name):
+        return {
+            "href": external_link_href,
+            "val": external_link_display_name,
+        }
+
+    @classmethod
+    def get_external_link_html(cls, event, external_link_href, external_link_display_name):
+        info = cls.get_external_link_info(event, external_link_href, external_link_display_name)
+        return make_link(info, '{val}')
+
+    def next_retry_date(self, sq):
+        """
+        Optionally override to configure a different retry backoff behavior
+        """
+        return now() + timedelta(hours=1)
+
+    def should_sync_order(self, order):
+        """
+        Optionally override this method to exclude certain orders from sync by returning ``False``
+        """
+        return True
+
+    @property
+    def mappings(self):
+        """
+        Implementations must override this property to provide the data mappings as a list of objects.
+
+        They can return instances of the ``StaticMapping`` `namedtuple` defined above, or create their own
+        class (e.g. a Django model).
+
+        :return: The returned objects must have at least the following properties:
+
+                - `id`: Unique identifier for this mapping. If the mappings are Django models, the database primary key
+                  should be used. This may be referenced in other mappings, to establish relations between objects.
+                - `pretix_model`: Which pretix model to use as data source in this mapping. Possible values are
+                  the keys of ``sourcefields.AVAILABLE_MODELS``
+                - `external_object_type`: Destination object type in the target system. opaque string of maximum 128 characters.
+                - `pretix_id_field`: Which pretix data field should be used to identify the mapped object. Any ``DataFieldInfo.key``
+                  returned by ``sourcefields.get_data_fields()`` for the combination of ``Event`` and ``pretix_model``.
+                - `external_id_field`: Destination identifier field in the target system.
+                - `property_mappings`: Mapping configuration as generated by ``PropertyMappingFormSet.to_property_mappings_list()``.
+        """
+        raise NotImplementedError
+
+    def sync_queued_orders(self, queued_orders):
+        """
+        This method should catch all Exceptions and handle them appropriately. It should never throw
+        an Exception, as that may block the entire queue.
+        """
+        for queue_item in queued_orders:
+            with transaction.atomic():
+                try:
+                    sq = (
+                        OrderSyncQueue.objects
+                        .select_for_update(of=OF_SELF, nowait=True)
+                        .select_related("order")
+                        .get(pk=queue_item.pk)
+                    )
+                    if sq.in_flight:
+                        continue
+                    sq.in_flight = True
+                    sq.in_flight_since = now()
+                    sq.save()
+                except DatabaseError:
+                    # Either select_for_update failed to lock the row, or we couldn't set in_flight
+                    # as this order is already in flight (UNIQUE violation). In either case, we ignore
+                    # this order for now.
+                    continue
+
+            try:
+                mapped_objects = self.sync_order(sq.order)
+                if not all(all(not res or res.sync_info.get("action", "") == "nothing_to_do" for res in res_list) for res_list in mapped_objects.values()):
+                    sq.order.log_action("pretix.event.order.data_sync.success", {
+                        "provider": self.identifier,
+                        "objects": {
+                            mapping_id: [osr and osr.to_result_dict() for osr in results]
+                            for mapping_id, results in mapped_objects.items()
+                        },
+                    })
+                sq.delete()
+            except UnrecoverableSyncError as e:
+                sq.set_sync_error(e.failure_mode, e.messages, e.full_message)
+            except RecoverableSyncError as e:
+                sq.failed_attempts += 1
+                sq.not_before = self.next_retry_date(sq)
+                # model changes saved by set_sync_error / clear_in_flight calls below
+                if sq.failed_attempts >= self.max_attempts:
+                    logger.exception('Failed to sync order (max attempts exceeded)')
+                    sentry_sdk.capture_exception(e)
+                    sq.set_sync_error("exceeded", e.messages, e.full_message)
+                else:
+                    logger.info(
+                        f"Could not sync order {sq.order.code} to {type(self).__name__} "
+                        f"(transient error, attempt #{sq.failed_attempts}, next {sq.not_before})",
+                        exc_info=True,
+                    )
+                    sq.clear_in_flight()
+            except Exception as e:
+                logger.exception('Failed to sync order (unhandled exception)')
+                sentry_sdk.capture_exception(e)
+                sq.set_sync_error("internal", [], str(e))
+
+    @cached_property
+    def data_fields(self):
+        return {
+            f.key: f
+            for f in get_data_fields(self.event)
+        }
+
+    def get_field_value(self, inputs, mapping_entry):
+        key = mapping_entry["pretix_field"]
+        try:
+            field = self.data_fields[key]
+        except KeyError:
+            with language(self.event.settings.locale):
+                raise SyncConfigError([_(
+                    'Field "{field_name}" does not exist. Please check your {provider_name} settings.'
+                ).format(field_name=key, provider_name=self.display_name)])
+        try:
+            input = inputs[field.required_input]
+        except KeyError:
+            with language(self.event.settings.locale):
+                raise SyncConfigError([_(
+                    'Field "{field_name}" requires {required_input}, but only got {available_inputs}. Please check your {provider_name} settings.'
+                ).format(field_name=key, required_input=field.required_input, available_inputs=", ".join(inputs.keys()), provider_name=self.display_name)])
+        val = field.getter(input)
+        if isinstance(val, list):
+            if field.enum_opts and mapping_entry.get("value_map"):
+                map = json.loads(mapping_entry["value_map"])
+                try:
+                    val = [map[el] for el in val]
+                except KeyError:
+                    with language(self.event.settings.locale):
+                        raise SyncConfigError([_(
+                            'Please update value mapping for field "{field_name}" - option "{val}" not assigned'
+                        ).format(field_name=key, val=val)])
+
+            val = ",".join(val)
+        return val
+
+    def get_properties(self, inputs: dict, property_mappings: List[dict]):
+        return [
+            (m["external_field"], self.get_field_value(inputs, m), m["overwrite"])
+            for m in property_mappings
+        ]
+
+    def sync_object_with_properties(
+            self,
+            external_id_field: str,
+            id_value,
+            properties: list,
+            inputs: dict,
+            mapping: ObjectMapping,
+            mapped_objects: dict,
+            **kwargs,
+    ) -> Optional[dict]:
+        """
+        This method is called for each object that needs to be created/updated in the external system -- which these are is
+        determined by the implementation of the `mapping` property.
+
+        :param external_id_field: Identifier field in the external system as provided in ``mapping.external_identifier``
+        :param id_value: Identifier contents as retrieved from the property specified by ``mapping.pretix_identifier`` of the model
+                         specified by ``mapping.pretix_model``
+        :param properties: All properties defined in ``mapping.property_mappings``, as list of three-tuples
+                           ``(external_field, value, overwrite)``
+        :param inputs: All pretix model instances from which data can be retrieved for this mapping.
+                       Dictionary mapping from sourcefields.ORDER_POSITION, .ORDER, .EVENT, .EVENT_OR_SUBEVENT to the
+                       relevant Django model.
+                       Most providers don't need to use this parameter directly, as `properties` and `id_value`
+                       already contain the values as evaluated from the available inputs.
+        :param mapping: The mapping object as returned by ``self.mappings``
+        :param mapped_objects: Information about objects that were synced in the same sync run, by mapping definitions
+                               *before* the current one in order of ``self.mappings``.
+                               Type is a dictionary ``{mapping.id: [list of OrderSyncResult objects]}``
+                               Useful to create associations between objects in the target system.
+
+        Example code to create return value::
+
+                 return {
+                    # optional:
+                    "action": "nothing_to_do",  # to inform that no action was taken, because the data was already up-to-date.
+                                                # other values for action (e.g. create, update) currently have no special
+                                                # meaning, but are visible for debugging purposes to admins.
+
+                    # optional:
+                    "external_link_href": "https://external-system.example.com/backend/link/to/contact/123/",
+                    "external_link_display_name": "Contact #123 - Jane Doe",
+                    "...optionally further values you need in mapped_objects for association": 123456789,
+                 }
+
+        The return value needs to be a JSON serializable dict, or None.
+
+        Return None only in case you decide this object should not be synced at all in this mapping. Do not return None in
+        case the object is already up-to-date in the target system (return "action": "nothing_to_do" instead).
+
+        This method needs to be idempotent, i.e. calling it multiple times with the same input values should create
+        only a single object in the target system.
+
+        Subsequent calls with the same mapping and id_value should update the existing object, instead of creating a new one.
+        In a SQL database, you might use an `INSERT OR UPDATE` or `UPSERT` statement; many REST APIs provide an equivalent API call.
+        """
+        raise NotImplementedError()
+
+    def sync_object(
+            self,
+            inputs: dict,
+            mapping,
+            mapped_objects: dict,
+    ):
+        logger.debug("Syncing object %r, %r, %r", inputs, mapping, mapped_objects)
+        properties = self.get_properties(inputs, mapping.property_mappings)
+        logger.debug("Properties: %r", properties)
+
+        id_value = self.get_field_value(inputs, {"pretix_field": mapping.pretix_id_field})
+        if not id_value:
+            return None
+
+        info = self.sync_object_with_properties(
+            external_id_field=mapping.external_id_field,
+            id_value=id_value,
+            properties=properties,
+            inputs=inputs,
+            mapping=mapping,
+            mapped_objects=mapped_objects,
+        )
+        if not info:
+            return None
+        external_link_href = info.pop('external_link_href', None)
+        external_link_display_name = info.pop('external_link_display_name', None)
+        obj, created = OrderSyncResult.objects.update_or_create(
+            order=inputs.get(ORDER), order_position=inputs.get(ORDER_POSITION), sync_provider=self.identifier,
+            mapping_id=mapping.id,
+            defaults=dict(
+                external_object_type=mapping.external_object_type,
+                external_id_field=mapping.external_id_field,
+                id_value=id_value,
+                external_link_href=external_link_href,
+                external_link_display_name=external_link_display_name,
+                sync_info=info,
+                transmitted=now(),
+            )
+        )
+        return obj
+
+    def sync_order(self, order):
+        if not self.should_sync_order(order):
+            logger.debug("Skipping order %r", order)
+            return
+
+        logger.debug("Syncing order %r", order)
+        positions = list(
+            order.all_positions
+            .prefetch_related("answers", "answers__question")
+            .select_related(
+                "voucher",
+            )
+        )
+        order_inputs = {ORDER: order, EVENT: self.event}
+        mapped_objects = {}
+        for mapping in self.mappings:
+            if mapping.pretix_model == 'Order':
+                mapped_objects[mapping.id] = [
+                    self.sync_object(order_inputs, mapping, mapped_objects)
+                ]
+            elif mapping.pretix_model == 'OrderPosition':
+                mapped_objects[mapping.id] = [
+                    self.sync_object({
+                        **order_inputs, EVENT_OR_SUBEVENT: op.subevent or self.event, ORDER_POSITION: op
+                    }, mapping, mapped_objects)
+                    for op in positions
+                ]
+            else:
+                raise SyncConfigError("Invalid pretix model '{}'".format(mapping.pretix_model))
+        self.finalize_sync_order(order)
+        return mapped_objects
+
+    def filter_mapped_objects(self, mapped_objects, inputs):
+        """
+        For order positions, only
+        """
+        if ORDER_POSITION in inputs:
+            return {
+                mapping_id: [
+                    osr for osr in results
+                    if osr and (osr.order_position_id is None or osr.order_position_id == inputs[ORDER_POSITION].id)
+                ]
+                for mapping_id, results in mapped_objects.items()
+            }
+        else:
+            return mapped_objects
+
+    def finalize_sync_order(self, order):
+        """
+        Called after ``sync_object`` has been called successfully for all objects of a specific order. Can
+        be used for saving bulk information per order.
+        """
+        pass
+
+    def close(self):
+        """
+        Called after all orders of an event have been synced. Can be used for clean-up tasks (e.g. closing
+        a session).
+        """
+        pass

src/pretix/base/datasync/sourcefields.py

@@ -0,0 +1,659 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+from collections import namedtuple
+from functools import partial
+
+from django.db.models import Max, Q
+from django.utils.translation import gettext_lazy as _, pgettext_lazy
+
+from pretix.base.models import Checkin, InvoiceAddress, Order, Question
+from pretix.base.settings import PERSON_NAME_SCHEMES
+from pretix.multidomain.urlreverse import build_absolute_uri
+
+
+def get_answer(op, question_identifier=None):
+    a = None
+    if op.addon_to:
+        if "answers" in getattr(op.addon_to, "_prefetched_objects_cache", {}):
+            try:
+                a = [
+                    a
+                    for a in op.addon_to.answers.all()
+                    if a.question.identifier == question_identifier
+                ][0]
+            except IndexError:
+                pass
+        else:
+            a = op.addon_to.answers.filter(
+                question__identifier=question_identifier
+            ).first()
+
+    if "answers" in getattr(op, "_prefetched_objects_cache", {}):
+        try:
+            a = [
+                a
+                for a in op.answers.all()
+                if a.question.identifier == question_identifier
+            ][0]
+        except IndexError:
+            pass
+    else:
+        a = op.answers.filter(question__identifier=question_identifier).first()
+
+    if not a:
+        return ""
+    else:
+        if a.question.type in (Question.TYPE_CHOICE, Question.TYPE_CHOICE_MULTIPLE):
+            return [str(o.identifier) for o in a.options.all()]
+        if a.question.type == Question.TYPE_BOOLEAN:
+            return a.answer == "True"
+        return a.answer
+
+
+def get_payment_date(order):
+    if order.status == Order.STATUS_PENDING:
+        return None
+
+    return isoformat_or_none(order.payments.aggregate(m=Max("payment_date"))["m"])
+
+
+def isoformat_or_none(dt):
+    return dt and dt.isoformat()
+
+
+def first_checkin_on_list(list_pk, position):
+    checkin = position.checkins.filter(
+        list__pk=list_pk, type=Checkin.TYPE_ENTRY
+    ).first()
+    if checkin:
+        return isoformat_or_none(checkin.datetime)
+
+
+def split_name_on_last_space(name, part):
+    name_parts = name.rsplit(" ", 1)
+    return name_parts[part] if len(name_parts) > part else ""
+
+
+def normalize_email(email):
+    if email:
+        local, host = email.split("@")
+        host = host.encode("idna").decode()
+        return f"{local}@{host}"
+    else:
+        return None
+
+
+def get_email_domain(email):
+    if email:
+        local, host = email.split("@")
+        return host
+    else:
+        return None
+
+
+ORDER_POSITION = 'position'
+ORDER = 'order'
+EVENT = 'event'
+EVENT_OR_SUBEVENT = 'event_or_subevent'
+AVAILABLE_MODELS = {
+    'OrderPosition': (ORDER_POSITION, ORDER, EVENT_OR_SUBEVENT, EVENT),
+    'Order': (ORDER, EVENT),
+}
+
+DataFieldCategory = namedtuple(
+    'DataFieldCategory',
+    field_names=('sort_index', 'label',),
+)
+
+CAT_ORDER_POSITION = DataFieldCategory(10, _('Order position details'))
+CAT_ATTENDEE = DataFieldCategory(11, _('Attendee details'))
+CAT_QUESTIONS = DataFieldCategory(12, _('Questions'))
+CAT_PRODUCT = DataFieldCategory(20, _('Product details'))
+CAT_ORDER = DataFieldCategory(21, _('Order details'))
+CAT_INVOICE_ADDRESS = DataFieldCategory(22, _('Invoice address'))
+CAT_EVENT = DataFieldCategory(30, _('Event information'))
+CAT_EVENT_OR_SUBEVENT = DataFieldCategory(31, pgettext_lazy('subevent', 'Event or date information'))
+
+DataFieldInfo = namedtuple(
+    'DataFieldInfo',
+    field_names=('required_input', 'category', 'key', 'label', 'type', 'enum_opts', 'getter', 'deprecated'),
+    defaults=[False]
+)
+
+
+def get_invoice_address_or_empty(order):
+    try:
+        return order.invoice_address
+    except InvoiceAddress.DoesNotExist:
+        return InvoiceAddress()
+
+
+def get_data_fields(event, for_model=None):
+    """
+    Returns tuple of (required_input, key, label, type, enum_opts, getter)
+
+    Type is one of the Question types as defined in Question.TYPE_CHOICES.
+
+    The data type of the return value of `getter` depends on `type`:
+    - TYPE_CHOICE_MULTIPLE: list of strings
+    - TYPE_CHOICE: list, containing zero or one strings
+    - TYPE_BOOLEAN: boolean
+    - all other (including TYPE_NUMBER): string
+    """
+    name_scheme = PERSON_NAME_SCHEMES[event.settings.name_scheme]
+    name_headers = []
+    if name_scheme and len(name_scheme["fields"]) > 1:
+        for k, label, w in name_scheme["fields"]:
+            name_headers.append(label)
+
+    src_fields = (
+        [
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_name",
+                _("Attendee name"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: position.attendee_name
+                or (position.addon_to.attendee_name if position.addon_to else None),
+            ),
+        ]
+        + [
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_name_" + k,
+                _("Attendee") + ": " + label,
+                Question.TYPE_STRING,
+                None,
+                partial(
+                    lambda k, position: (
+                        position.attendee_name_parts
+                        or (position.addon_to.attendee_name_parts if position.addon_to else {})
+                        or {}
+                    ).get(k, ""),
+                    k,
+                ),
+                deprecated=len(name_scheme["fields"]) == 1,
+            )
+            for k, label, w in name_scheme["fields"]
+        ]
+        + [
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_email",
+                _("Attendee email"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: normalize_email(
+                    position.attendee_email
+                    or (position.addon_to.attendee_email if position.addon_to else None)
+                ),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_or_order_email",
+                _("Attendee or order email"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: normalize_email(
+                    position.attendee_email
+                    or (position.addon_to.attendee_email if position.addon_to else None)
+                    or position.order.email
+                ),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_company",
+                _("Attendee company"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: position.company or (position.addon_to.company if position.addon_to else None),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_street",
+                _("Attendee address street"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: position.street or (position.addon_to.street if position.addon_to else None),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_zipcode",
+                _("Attendee address ZIP code"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: position.zipcode or (position.addon_to.zipcode if position.addon_to else None),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_city",
+                _("Attendee address city"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: position.city or (position.addon_to.city if position.addon_to else None),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_country",
+                _("Attendee address country"),
+                Question.TYPE_COUNTRYCODE,
+                None,
+                lambda position: str(
+                    position.country or (position.addon_to.attendee_name if position.addon_to else "")
+                ),
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_company",
+                _("Invoice address company"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: get_invoice_address_or_empty(order).company,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_name",
+                _("Invoice address name"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: get_invoice_address_or_empty(order).name,
+            ),
+        ]
+        + [
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_name_" + k,
+                _("Invoice address") + ": " + label,
+                Question.TYPE_STRING,
+                None,
+                partial(
+                    lambda k, order: (get_invoice_address_or_empty(order).name_parts or {}).get(
+                        k, ""
+                    ),
+                    k,
+                ),
+                deprecated=len(name_scheme["fields"]) == 1,
+            )
+            for k, label, w in name_scheme["fields"]
+        ]
+        + [
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_street",
+                _("Invoice address street"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: get_invoice_address_or_empty(order).street,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_zipcode",
+                _("Invoice address ZIP code"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: get_invoice_address_or_empty(order).zipcode,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_city",
+                _("Invoice address city"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: get_invoice_address_or_empty(order).city,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_country",
+                _("Invoice address country"),
+                Question.TYPE_COUNTRYCODE,
+                None,
+                lambda order: str(get_invoice_address_or_empty(order).country),
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "email",
+                _("Order email"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: normalize_email(order.email),
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "email_domain",
+                _("Order email domain"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: get_email_domain(normalize_email(order.email)),
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "order_code",
+                _("Order code"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: order.code,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "event_order_code",
+                _("Event and order code"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: order.full_code,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "order_total",
+                _("Order total"),
+                Question.TYPE_NUMBER,
+                None,
+                lambda order: str(order.total),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_PRODUCT,
+                "product",
+                _("Product and variation name"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: str(
+                    str(position.item.internal_name or position.item.name)
+                    + ((" – " + str(position.variation.value)) if position.variation else "")
+                ),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_PRODUCT,
+                "product_id",
+                _("Product ID"),
+                Question.TYPE_NUMBER,
+                None,
+                lambda position: str(position.item.pk),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_PRODUCT,
+                "product_is_admission",
+                _("Product is admission product"),
+                Question.TYPE_BOOLEAN,
+                None,
+                lambda position: bool(position.item.admission),
+            ),
+            DataFieldInfo(
+                EVENT,
+                CAT_EVENT,
+                "event_slug",
+                _("Event short form"),
+                Question.TYPE_STRING,
+                None,
+                lambda event: str(event.slug),
+            ),
+            DataFieldInfo(
+                EVENT,
+                CAT_EVENT,
+                "event_name",
+                _("Event name"),
+                Question.TYPE_STRING,
+                None,
+                lambda event: str(event.name),
+            ),
+            DataFieldInfo(
+                EVENT_OR_SUBEVENT,
+                CAT_EVENT_OR_SUBEVENT,
+                "event_date_from",
+                _("Event start date"),
+                Question.TYPE_DATETIME,
+                None,
+                lambda event_or_subevent: isoformat_or_none(event_or_subevent.date_from),
+            ),
+            DataFieldInfo(
+                EVENT_OR_SUBEVENT,
+                CAT_EVENT_OR_SUBEVENT,
+                "event_date_to",
+                _("Event end date"),
+                Question.TYPE_DATETIME,
+                None,
+                lambda event_or_subevent: isoformat_or_none(event_or_subevent.date_to),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ORDER_POSITION,
+                "voucher_code",
+                _("Voucher code"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: position.voucher.code if position.voucher_id else "",
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ORDER_POSITION,
+                "ticket_id",
+                _("Order code and position number"),
+                Question.TYPE_STRING,
+                None,
+                lambda position: position.code,
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ORDER_POSITION,
+                "ticket_price",
+                _("Ticket price"),
+                Question.TYPE_NUMBER,
+                None,
+                lambda position: str(position.price),
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "order_status",
+                _("Order status"),
+                Question.TYPE_CHOICE,
+                Order.STATUS_CHOICE,
+                lambda order: [order.status],
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ORDER_POSITION,
+                "ticket_status",
+                _("Ticket status"),
+                Question.TYPE_CHOICE,
+                Order.STATUS_CHOICE,
+                lambda position: [Order.STATUS_CANCELED if position.canceled else position.order.status],
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "order_date",
+                _("Order date and time"),
+                Question.TYPE_DATETIME,
+                None,
+                lambda order: order.datetime.isoformat(),
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "payment_date",
+                _("Payment date and time"),
+                Question.TYPE_DATETIME,
+                None,
+                get_payment_date,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "order_locale",
+                _("Order locale"),
+                Question.TYPE_CHOICE,
+                [(lc, lc) for lc in event.settings.locales],
+                lambda order: [order.locale],
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ORDER_POSITION,
+                "position_id",
+                _("Order position ID"),
+                Question.TYPE_NUMBER,
+                None,
+                lambda op: str(op.pk),
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_ORDER,
+                "presale_order_url",
+                _("Order link"),
+                Question.TYPE_STRING,
+                None,
+                lambda order: build_absolute_uri(
+                    event,
+                    'presale:event.order', kwargs={
+                        'order': order.code,
+                        'secret': order.secret,
+                    }
+                ),
+            ),
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ORDER_POSITION,
+                "presale_ticket_url",
+                _("Ticket link"),
+                Question.TYPE_STRING,
+                None,
+                lambda op: build_absolute_uri(
+                    event,
+                    'presale:event.order.position', kwargs={
+                        'order': op.order.code,
+                        'secret': op.web_secret,
+                        'position': op.positionid
+                    }
+                ),
+            ),
+        ]
+        + [
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ORDER_POSITION,
+                "checkin_date_" + str(cl.pk),
+                _("Check-in datetime on list {}").format(cl.name),
+                Question.TYPE_DATETIME,
+                None,
+                partial(first_checkin_on_list, cl.pk),
+            )
+            for cl in event.checkin_lists.all()
+        ]
+        + [
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_QUESTIONS,
+                "question_" + q.identifier,
+                _("Question: {name}").format(name=str(q.question)),
+                q.type,
+                get_enum_opts(q),
+                partial(lambda qq, position: get_answer(position, qq.identifier), q),
+            )
+            for q in event.questions.filter(~Q(type=Question.TYPE_FILE)).prefetch_related("options")
+        ]
+    )
+    if not any(field_name == "given_name" for field_name, label, weight in name_scheme["fields"]):
+        src_fields += [
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_name_given_name",
+                _("Attendee") + ": " + _("Given name") + " (⚠️ auto-generated, not recommended)",
+                Question.TYPE_STRING,
+                None,
+                lambda position: split_name_on_last_space(position.attendee_name, part=0),
+                deprecated=True,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_name_given_name",
+                _("Invoice address") + ": " + _("Given name") + " (⚠️ auto-generated, not recommended)",
+                Question.TYPE_STRING,
+                None,
+                lambda order: split_name_on_last_space(get_invoice_address_or_empty(order).name, part=0),
+                deprecated=True,
+            ),
+        ]
+
+    if not any(field_name == "family_name" for field_name, label, weight in name_scheme["fields"]):
+        src_fields += [
+            DataFieldInfo(
+                ORDER_POSITION,
+                CAT_ATTENDEE,
+                "attendee_name_family_name",
+                _("Attendee") + ": " + _("Family name") + " (⚠️ auto-generated, not recommended)",
+                Question.TYPE_STRING,
+                None,
+                lambda position: split_name_on_last_space(position.attendee_name, part=1),
+                deprecated=True,
+            ),
+            DataFieldInfo(
+                ORDER,
+                CAT_INVOICE_ADDRESS,
+                "invoice_address_name_family_name",
+                _("Invoice address") + ": " + _("Family name") + " (⚠️ auto-generated, not recommended)",
+                Question.TYPE_STRING,
+                None,
+                lambda order: split_name_on_last_space(get_invoice_address_or_empty(order).name, part=1),
+                deprecated=True,
+            ),
+        ]
+
+    if for_model:
+        available_inputs = AVAILABLE_MODELS[for_model]
+        return [
+            f for f in src_fields if f.required_input in available_inputs
+        ]
+    else:
+        return src_fields
+
+
+def get_enum_opts(q):
+    if q.type in (Question.TYPE_CHOICE, Question.TYPE_CHOICE_MULTIPLE):
+        return [(opt.identifier, opt.answer) for opt in q.options.all()]
+    else:
+        return None

src/pretix/base/datasync/utils.py

@@ -0,0 +1,123 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+from typing import List, Tuple
+
+from pretix.base.datasync.datasync import SyncConfigError
+from pretix.base.models.datasync import (
+    MODE_APPEND_LIST, MODE_OVERWRITE, MODE_SET_IF_EMPTY, MODE_SET_IF_NEW,
+)
+
+
+def assign_properties(
+    new_values: List[Tuple[str, str, str]], old_values: dict, is_new, list_sep
+):
+    """
+    Generates a dictionary mapping property keys to new values, handling conditional overwrites and list updates
+    according to an update mode specified per property.
+
+    Supported update modes are:
+     - `MODE_OVERWRITE`:  Replaces the existing value with the new value.
+     - `MODE_SET_IF_NEW`: Only sets the property if `is_new` is True.
+     - `MODE_SET_IF_EMPTY`: Only sets the property if the field is empty or missing in old_values.
+     - `MODE_APPEND_LIST`: Appends the new value to the list from old_values (or the empty list if missing),
+                           using `list_sep` as a separator.
+
+    :param new_values: List of tuples, where each tuple contains (field_name, new_value, update_mode).
+    :param old_values: Dictionary, current property values in the external system.
+    :param is_new: Boolean, whether the object will be newly created in the external system.
+    :param list_sep: If string, used as a separator for MODE_APPEND_LIST. If None, native lists are used.
+    :raises SyncConfigError: If an invalid update mode is specified.
+    :returns: A dictionary containing the properties that need to be updated in the external system.
+    """
+
+    out = {}
+
+    for field_name, new_value, update_mode in new_values:
+        if update_mode == MODE_OVERWRITE:
+            out[field_name] = new_value
+            continue
+        elif update_mode == MODE_SET_IF_NEW and not is_new:
+            continue
+        if not new_value:
+            continue
+
+        current_value = old_values.get(field_name, out.get(field_name, ""))
+        if update_mode in (MODE_SET_IF_EMPTY, MODE_SET_IF_NEW):
+            if not current_value:
+                out[field_name] = new_value
+        elif update_mode == MODE_APPEND_LIST:
+            _add_to_list(out, field_name, current_value, new_value, list_sep)
+        else:
+            raise SyncConfigError(["Invalid update mode " + update_mode])
+    return out
+
+
+def _add_to_list(out, field_name, current_value, new_item, list_sep):
+    new_item = str(new_item)
+    if list_sep is not None:
+        new_item = new_item.replace(list_sep, "")
+        current_value = current_value.split(list_sep) if current_value else []
+    elif not isinstance(current_value, (list, tuple)):
+        current_value = [str(current_value)]
+    if new_item not in current_value:
+        new_list = current_value + [new_item]
+        if list_sep is not None:
+            new_list = list_sep.join(new_list)
+        out[field_name] = new_list
+
+
+def translate_property_mappings(property_mappings, checkin_list_map):
+    """
+    To properly handle copied events, users of data fields as provided by get_data_fields need to register to the
+    event_copy_data signal and translate all stored references to those fields using this method.
+
+    For example, if you store your mappings in a custom Django model with a ForeignKey to Event:
+
+    .. code-block:: python
+
+        @receiver(signal=event_copy_data, dispatch_uid="my_sync_event_copy_data")
+        def event_copy_data_receiver(sender, other, checkin_list_map, **kwargs):
+            object_mappings = other.my_object_mappings.all()
+            object_mapping_map = {}
+            for om in object_mappings:
+                om = copy.copy(om)
+                object_mapping_map[om.pk] = om
+                om.pk = None
+                om.event = sender
+                om.property_mappings = translate_property_mappings(om.property_mappings, checkin_list_map)
+                om.save()
+
+    """
+    mappings = []
+
+    for mapping in property_mappings:
+        pretix_field = mapping["pretix_field"]
+        if pretix_field.startswith("checkin_date_"):
+            old_id = int(pretix_field[len("checkin_date_"):])
+            if old_id not in checkin_list_map:
+                # old_id might not be in checkin_list_map, because copying of an event series only copies check-in
+                # lists covering the whole series, not individual dates.
+                pretix_field = "_invalid_" + pretix_field
+            else:
+                pretix_field = "checkin_date_%d" % checkin_list_map[old_id].pk
+        mappings.append({**mapping, "pretix_field": pretix_field})
+    return mappings

src/pretix/base/email.py

@@ -24,6 +24,7 @@ from itertools import groupby
 from smtplib import SMTPResponseException
 from typing import TypeVar
 
+import bleach
 import css_inline
 from django.conf import settings
 from django.core.mail.backends.smtp import EmailBackend
@@ -34,7 +35,10 @@ from django.utils.translation import get_language, gettext_lazy as _
 
 from pretix.base.models import Event
 from pretix.base.signals import register_html_mail_renderers
-from pretix.base.templatetags.rich_text import markdown_compile_email
+from pretix.base.templatetags.rich_text import (
+    DEFAULT_CALLBACKS, EMAIL_RE, URL_RE, abslink_callback,
+    markdown_compile_email, truelink_callback,
+)
 from pretix.helpers.format import SafeFormatter, format_map
 
 from pretix.base.services.placeholders import (  # noqa
@@ -133,13 +137,24 @@ class TemplateBasedMailRenderer(BaseHTMLMailRenderer):
     def template_name(self):
         raise NotImplementedError()
 
-    def compile_markdown(self, plaintext):
-        return markdown_compile_email(plaintext)
+    def compile_markdown(self, plaintext, context=None):
+        return markdown_compile_email(plaintext, context=context)
 
     def render(self, plain_body: str, plain_signature: str, subject: str, order, position, context) -> str:
-        body_md = self.compile_markdown(plain_body)
+        body_md = self.compile_markdown(plain_body, context)
         if context:
-            body_md = format_map(body_md, context=context, mode=SafeFormatter.MODE_RICH_TO_HTML)
+            linker = bleach.Linker(
+                url_re=URL_RE,
+                email_re=EMAIL_RE,
+                callbacks=DEFAULT_CALLBACKS + [truelink_callback, abslink_callback],
+                parse_email=True
+            )
+            body_md = format_map(
+                body_md,
+                context=context,
+                mode=SafeFormatter.MODE_RICH_TO_HTML,
+                linkifier=linker
+            )
         htmlctx = {
             'site': settings.PRETIX_INSTANCE_NAME,
             'site_url': settings.SITE_URL,

src/pretix/base/exporters/orderlist.py

@@ -68,6 +68,7 @@ from ...control.forms.filter import get_all_payment_providers
 from ...helpers import GroupConcat
 from ...helpers.iter import chunked_iterable
 from ...helpers.safe_openpyxl import remove_invalid_excel_chars
+from ...multidomain.urlreverse import build_absolute_uri
 from ..exporter import (
     ListExporter, MultiSheetListExporter, OrganizerLevelExportMixin,
 )
@@ -287,6 +288,7 @@ class OrderListExporter(MultiSheetListExporter):
         headers.append(_('Email address verified'))
         headers.append(_('External customer ID'))
         headers.append(_('Payment providers'))
+        headers.append(_('Order link'))
         if form_data.get('include_payment_amounts'):
             payment_methods = self._get_all_payment_methods(qs)
             for id, vn in payment_methods:
@@ -402,6 +404,13 @@ class OrderListExporter(MultiSheetListExporter):
                 if p and p != 'free'
             ]))
 
+            row.append(
+                build_absolute_uri(order.event, 'presale:event.order', kwargs={
+                    'order': order.code,
+                    'secret': order.secret,
+                })
+            )
+
             if form_data.get('include_payment_amounts'):
                 payment_methods = self._get_all_payment_methods(qs)
                 for id, vn in payment_methods:
@@ -659,6 +668,7 @@ class OrderListExporter(MultiSheetListExporter):
             _('External customer ID'),
             _('Check-in lists'),
             _('Payment providers'),
+            _('Position order link')
         ]
 
         # get meta_data labels from first cached event
@@ -803,6 +813,14 @@ class OrderListExporter(MultiSheetListExporter):
                     if p and p != 'free'
                 ]))
 
+                row.append(
+                    build_absolute_uri(order.event, 'presale:event.order.position', kwargs={
+                        'order': order.code,
+                        'secret': op.web_secret,
+                        'position': op.positionid
+                    })
+                )
+
                 if has_subevents:
                     if op.subevent:
                         row += op.subevent.meta_data.values()

src/pretix/base/forms/questions.py

@@ -54,7 +54,6 @@ from django.core.validators import (
 from django.db.models import QuerySet
 from django.forms import Select, widgets
 from django.forms.widgets import FILE_INPUT_CONTRADICTION
-from django.urls import reverse
 from django.utils.formats import date_format
 from django.utils.html import escape
 from django.utils.safestring import mark_safe
@@ -78,6 +77,7 @@ from pretix.base.forms.widgets import (
 from pretix.base.i18n import (
     get_babel_locale, get_language_without_region, language,
 )
+from pretix.base.invoicing.transmission import get_transmission_types
 from pretix.base.models import InvoiceAddress, Item, Question, QuestionOption
 from pretix.base.models.tax import ask_for_vat_id
 from pretix.base.services.tax import (
@@ -736,7 +736,7 @@ class BaseQuestionsForm(forms.Form):
                 initial=country,
                 widget=forms.Select(attrs={
                     'autocomplete': 'country',
-                    'data-country-information-url': reverse('js_helpers.states'),
+                    'data-trigger-address-info': 'on',
                 }),
             )
             c = [('', '---')]
@@ -896,10 +896,17 @@ class BaseQuestionsForm(forms.Form):
                             'Please enter a date no later than {max}.',
                             max=date_format(q.valid_date_max, "SHORT_DATE_FORMAT"),
                         )
+                if initial and initial.answer:
+                    try:
+                        _initial = dateutil.parser.parse(initial.answer).date()
+                    except dateutil.parser.ParserError:
+                        _initial = None
+                else:
+                    _initial = None
                 field = forms.DateField(
                     label=label, required=required,
                     help_text=help_text,
-                    initial=dateutil.parser.parse(initial.answer).date() if initial and initial.answer else None,
+                    initial=_initial,
                     widget=DatePickerWidget(attrs),
                 )
                 if q.valid_date_min:
@@ -907,10 +914,17 @@ class BaseQuestionsForm(forms.Form):
                 if q.valid_date_max:
                     field.validators.append(MaxDateValidator(q.valid_date_max))
             elif q.type == Question.TYPE_TIME:
+                if initial and initial.answer:
+                    try:
+                        _initial = dateutil.parser.parse(initial.answer).time()
+                    except dateutil.parser.ParserError:
+                        _initial = None
+                else:
+                    _initial = None
                 field = forms.TimeField(
                     label=label, required=required,
                     help_text=help_text,
-                    initial=dateutil.parser.parse(initial.answer).time() if initial and initial.answer else None,
+                    initial=_initial,
                     widget=TimePickerWidget(time_format=get_format_without_seconds('TIME_INPUT_FORMATS')),
                 )
             elif q.type == Question.TYPE_DATETIME:
@@ -931,10 +945,19 @@ class BaseQuestionsForm(forms.Form):
                             'Please enter a date and time no later than {max}.',
                             max=date_format(q.valid_datetime_max, "SHORT_DATETIME_FORMAT"),
                         )
+
+                if initial and initial.answer:
+                    try:
+                        _initial = dateutil.parser.parse(initial.answer).astimezone(tz)
+                    except dateutil.parser.ParserError:
+                        _initial = None
+                else:
+                    _initial = None
+
                 field = SplitDateTimeField(
                     label=label, required=required,
                     help_text=help_text,
-                    initial=dateutil.parser.parse(initial.answer).astimezone(tz) if initial and initial.answer else None,
+                    initial=_initial,
                     widget=SplitDateTimePickerWidget(
                         time_format=get_format_without_seconds('TIME_INPUT_FORMATS'),
                         min_date=q.valid_datetime_min,
@@ -1119,11 +1142,19 @@ class BaseInvoiceAddressForm(forms.ModelForm):
         if (not kwargs.get('instance') or not kwargs['instance'].country) and not kwargs["initial"].get("country"):
             kwargs['initial']['country'] = guess_country_from_request(self.request, self.event)
 
+        if kwargs.get('instance'):
+            kwargs['initial'].update(kwargs['instance'].transmission_info or {})
+            kwargs['initial']['transmission_type'] = kwargs['instance'].transmission_type
+
         super().__init__(*args, **kwargs)
 
+        # Individuals do not have a company name or VAT ID
         self.fields["company"].widget.attrs["data-display-dependency"] = f'input[name="{self.add_prefix("is_business")}"][value="business"]'
         self.fields["vat_id"].widget.attrs["data-display-dependency"] = f'input[name="{self.add_prefix("is_business")}"][value="business"]'
 
+        # The internal reference is a very business-specific field and might confuse non-business users
+        self.fields["internal_reference"].widget.attrs["data-display-dependency"] = f'input[name="{self.add_prefix("is_business")}"][value="business"]'
+
         if not self.ask_vat_id:
             del self.fields['vat_id']
         elif self.validate_vat_id:
@@ -1139,8 +1170,17 @@ class BaseInvoiceAddressForm(forms.ModelForm):
                 str(_('If you are registered in Switzerland, you can enter your UID instead.')),
             ])
 
+        transmission_type_choices = [
+            (t.identifier, t.public_name) for t in get_transmission_types()
+        ]
+        if not self.address_required or self.all_optional:
+            transmission_type_choices.insert(0, ("-", _("No invoice requested")))
+        self.fields['transmission_type'] = forms.ChoiceField(
+            label=_('Invoice transmission method'),
+            choices=transmission_type_choices
+        )
+
         self.fields['country'].choices = CachedCountries()
-        self.fields['country'].widget.attrs['data-country-information-url'] = reverse('js_helpers.states')
 
         c = [('', '---')]
         fprefix = self.prefix + '-' if self.prefix else ''
@@ -1219,6 +1259,44 @@ class BaseInvoiceAddressForm(forms.ModelForm):
         else:
             del self.fields['custom_field']
 
+        # Add transmission type specific fields
+        for transmission_type in get_transmission_types():
+            for k, f in transmission_type.invoice_address_form_fields.items():
+                if (
+                    transmission_type.identifier == "email" and
+                    k in ("transmission_email_other", "transmission_email_address") and
+                    (
+                        event.settings.invoice_generate == "False" or
+                        not event.settings.invoice_email_attachment
+                    )
+                ):
+                    # This looks like a very unclean hack (and probably really is one), but hear me out:
+                    # With pretix 2025.7, we introduced invoice transmission types and added the "send to another email"
+                    # feature for the email provider. This feature was previously part of the bank transfer payment
+                    # provider and opt-in. With this change, this feature becomes available for all pretix shops, which
+                    # we think is a good thing in the long run as it is an useful feature for every business customer.
+                    # However, there's two scenarios where it might be bad that we add it without opt-in:
+                    # - When the organizer has turned off invoice generation in pretix and is collecting invoice information
+                    #   only for other reasons or to later create invoices with a separate software. In this case it
+                    #   would be very bad for the user to be able to ask for the invoice to be sent somewhere else, and
+                    #   that information then be ignored because the organizer has not updated their process.
+                    # - When the organizer has intentionally turned off invoices being attached to emails, because that
+                    #   would somehow be a contradiction.
+                    # Now, the obvious solution would be to make the TransmissionType.invoice_address_form_fields property
+                    # a function that depends on the event as an input. However, I believe this is the wrong approach
+                    # over the long term. As a generalized concept, we DO want invoice address collection to be
+                    # *independent* of event settings, in order to (later) e.g. implement invoice address editing within
+                    # customer accounts. Hence, this hack directly in the form to provide (some) backwards compatibility
+                    # only for the default transmission type "email".
+                    continue
+
+                self.fields[k] = f
+                f._required = f.required
+                f.required = False
+                f.widget.is_required = False
+                if 'required' in f.widget.attrs:
+                    del f.widget.attrs['required']
+
         for k, v in self.fields.items():
             if v.widget.attrs.get('autocomplete') or k == 'name_parts':
                 autocomplete = v.widget.attrs.get('autocomplete', '')
@@ -1227,6 +1305,10 @@ class BaseInvoiceAddressForm(forms.ModelForm):
                 else:
                     v.widget.attrs['autocomplete'] = 'section-invoice billing ' + autocomplete
 
+        self.fields['country'].widget.attrs['data-trigger-address-info'] = 'on'
+        self.fields['is_business'].widget.attrs['data-trigger-address-info'] = 'on'
+        self.fields['transmission_type'].widget.attrs['data-trigger-address-info'] = 'on'
+
     def clean(self):
         from pretix.base.addressvalidation import \
             validate_address  # local import to prevent impact on startup time
@@ -1254,11 +1336,23 @@ class BaseInvoiceAddressForm(forms.ModelForm):
 
         self.instance.name_parts = data.get('name_parts')
 
-        if all(
-                not v for k, v in data.items() if k not in ('is_business', 'country', 'name_parts')
-        ) and name_parts_is_empty(data.get('name_parts', {})):
+        form_is_empty = all(
+            not v for k, v in data.items()
+            if k not in ('is_business', 'country', 'name_parts', 'transmission_type') and not k.startswith("transmission_")
+        ) and name_parts_is_empty(data.get('name_parts', {}))
+
+        if form_is_empty:
             # Do not save the country if it is the only field set -- we don't know the user even checked it!
             self.cleaned_data['country'] = ''
+            if data.get('transmission_type') == "-":
+                data['transmission_type'] = 'email'  # our actual default for now, we can revisit this later
+
+        else:
+            if data.get('transmission_type') == "-":
+                raise ValidationError(
+                    {"transmission_type": _("If you enter an invoice address, you also need to select an invoice "
+                                            "transmission method.")}
+                )
 
         if self.validate_vat_id and self.instance.vat_id_validated and 'vat_id' not in self.changed_data:
             pass
@@ -1280,6 +1374,37 @@ class BaseInvoiceAddressForm(forms.ModelForm):
         else:
             self.instance.vat_id_validated = False
 
+        for transmission_type in get_transmission_types():
+            if transmission_type.identifier == data.get("transmission_type"):
+                if not transmission_type.is_available(self.event, data.get("country"), data.get("is_business")):
+                    raise ValidationError({
+                        "transmission_type": _("The selected transmission type is not available in your country or for "
+                                               "your type of address.")
+                    })
+
+                required_fields = transmission_type.invoice_address_form_fields_required(data.get("country"), data.get("is_business"))
+                for r in required_fields:
+                    if r not in self.fields:
+                        logger.info(f"Transmission type {transmission_type.identifier} required field {r} which is not available.")
+                        raise ValidationError(
+                            _("The selected type of invoice transmission requires a field that is currently not "
+                              "available, please reach out to the organizer.")
+                        )
+                    if not data.get(r):
+                        raise ValidationError({r: _("This field is required for the selected type of invoice transmission.")})
+
+                self.instance.transmission_type = transmission_type.identifier
+                self.instance.transmission_info = {
+                    k: data.get(k) for k in transmission_type.invoice_address_form_fields
+                }
+            elif transmission_type.exclusive:
+                if transmission_type.is_available(self.event, data.get("country"), data.get("is_business")):
+                    raise ValidationError({
+                        "transmission_type": "The transmission type '%s' must be used for this country or address type." % (
+                            transmission_type.public_name,
+                        )
+                    })
+
 
 class BaseInvoiceNameForm(BaseInvoiceAddressForm):
     def __init__(self, *args, **kwargs):

src/pretix/base/invoicing/__init__.py

@@ -0,0 +1,21 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#

src/pretix/base/invoicing/email.py

@@ -0,0 +1,173 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+from django import forms
+from django.utils.timezone import now
+from django.utils.translation import gettext_lazy as _
+from django_countries.fields import Country
+from i18nfield.strings import LazyI18nString
+
+from pretix.base.email import get_email_context
+from pretix.base.i18n import language
+from pretix.base.invoicing.transmission import (
+    TransmissionProvider, TransmissionType, transmission_providers,
+    transmission_types,
+)
+from pretix.base.models import Invoice, InvoiceAddress
+from pretix.base.services.mail import SendMailException, mail, render_mail
+from pretix.helpers.format import format_map
+
+
+@transmission_types.new()
+class EmailTransmissionType(TransmissionType):
+    identifier = "email"
+    verbose_name = _("Email")
+    priority = 1000
+
+    @property
+    def invoice_address_form_fields(self) -> dict:
+        return {
+            "transmission_email_other": forms.BooleanField(
+                label=_("Email invoice directly to accounting department"),
+                help_text=_("If not selected, the invoice will be sent to you using the email address listed above."),
+                required=False,
+            ),
+            "transmission_email_address": forms.EmailField(
+                label=_("Email address for invoice"),
+                widget=forms.EmailInput(
+                    attrs={"data-display-dependency": "#id_transmission_email_other"}
+                )
+            )
+        }
+
+    def invoice_address_form_fields_visible(self, country: Country, is_business: bool):
+        if is_business:
+            # We don't want ask non-business users if they have an accounting department ;)
+            return {"transmission_email_other", "transmission_email_address"}
+        return set()
+
+    def is_available(self, event, country: Country, is_business: bool):
+        # Skip availability check since provider is always available and we do not want to end up without invoice
+        # transmission type
+        return True
+
+    def transmission_info_to_form_data(self, transmission_info: dict) -> dict:
+        return {
+            "transmission_email_other": bool(transmission_info.get("transmission_email_address")),
+            "transmission_email_address": transmission_info.get("transmission_email_address"),
+        }
+
+    def form_data_to_transmission_info(self, form_data: dict) -> dict:
+        if form_data.get("transmission_email_other") and form_data.get("transmission_email_address"):
+            return {
+                "transmission_email_address": form_data["transmission_email_address"],
+            }
+        return {}
+
+
+@transmission_providers.new()
+class EmailTransmissionProvider(TransmissionProvider):
+    identifier = "email_pdf"
+    type = "email"
+    verbose_name = _("PDF via email")
+    priority = 1000
+    testmode_supported = True
+
+    def is_ready(self, event) -> bool:
+        return True
+
+    def is_available(self, event, country: Country, is_business: bool) -> bool:
+        return True
+
+    def transmit(self, invoice: Invoice):
+        info = (invoice.invoice_to_transmission_info or {})
+        if info.get("transmission_email_address"):
+            recipient = info["transmission_email_address"]
+        else:
+            recipient = invoice.order.email
+
+        if not recipient:
+            invoice.transmission_status = Invoice.TRANSMISSION_STATUS_FAILED
+            invoice.transmission_date = now()
+            invoice.save(update_fields=["transmission_status", "transmission_date"])
+            invoice.order.log_action(
+                "pretix.event.order.invoice.sending_failed",
+                data={
+                    "full_invoice_no": invoice.full_invoice_no,
+                    "transmission_provider": "email_pdf",
+                    "transmission_type": "email",
+                    "data": {
+                        "reason": "no_recipient",
+                    },
+                }
+            )
+            return
+
+        with language(invoice.order.locale, invoice.order.event.settings.region):
+            context = get_email_context(
+                event=invoice.order.event,
+                order=invoice.order,
+                invoice=invoice,
+                event_or_subevent=invoice.order.event,
+                invoice_address=getattr(invoice.order, 'invoice_address', None) or InvoiceAddress()
+            )
+            template = invoice.order.event.settings.get('mail_text_order_invoice', as_type=LazyI18nString)
+            subject = invoice.order.event.settings.get('mail_subject_order_invoice', as_type=LazyI18nString)
+
+            try:
+                # Do not set to completed because that is done by the email sending task
+                subject = format_map(subject, context)
+                email_content = render_mail(template, context)
+                mail(
+                    [recipient],
+                    subject,
+                    template,
+                    context=context,
+                    event=invoice.order.event,
+                    locale=invoice.order.locale,
+                    order=invoice.order,
+                    invoices=[invoice],
+                    attach_tickets=False,
+                    auto_email=True,
+                    attach_ical=False,
+                    plain_text_only=True,
+                    no_order_links=True,
+                )
+            except SendMailException:
+                raise
+            else:
+                invoice.order.log_action(
+                    'pretix.event.order.email.invoice',
+                    user=None,
+                    auth=None,
+                    data={
+                        'subject': subject,
+                        'message': email_content,
+                        'position': None,
+                        'recipient': recipient,
+                        'invoices': [invoice.pk],
+                        'attach_tickets': False,
+                        'attach_ical': False,
+                        'attach_other_files': [],
+                        'attach_cached_files': [],
+                    }
+                )

src/pretix/base/invoicing/national.py

@@ -0,0 +1,84 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+from django import forms
+from django.core.validators import RegexValidator
+from django.utils.translation import pgettext, pgettext_lazy
+from django_countries.fields import Country
+from localflavor.it.forms import ITSocialSecurityNumberField
+
+from pretix.base.invoicing.transmission import (
+    TransmissionType, transmission_types,
+)
+
+
+@transmission_types.new()
+class ItalianSdITransmissionType(TransmissionType):
+    identifier = "it_sdi"
+    verbose_name = pgettext_lazy("italian_invoice", "Italian Exchange System (SdI)")
+    public_name = pgettext_lazy("italian_invoice", "Exchange System (SdI)")
+    exclusive = True
+    enforce_transmission = True
+
+    def is_available(self, event, country: Country, is_business: bool):
+        return str(country) == "IT" and super().is_available(event, country, is_business)
+
+    @property
+    def invoice_address_form_fields(self) -> dict:
+        return {
+            "transmission_it_sdi_codice_fiscale": ITSocialSecurityNumberField(
+                label=pgettext_lazy("italian_invoice", "Fiscal code"),
+                required=False,
+            ),
+            "transmission_it_sdi_pec": forms.EmailField(
+                label=pgettext_lazy("italian_invoice", "Address for certified electronic mail"),
+                widget=forms.EmailInput()
+            ),
+            "transmission_it_sdi_recipient_code": forms.CharField(
+                label=pgettext_lazy("italian_invoice", "Recipient code"),
+                validators=[
+                    RegexValidator("^[A-Z0-9]{6,7}$")
+                ]
+            ),
+        }
+
+    def invoice_address_form_fields_visible(self, country: Country, is_business: bool):
+        if is_business:
+            return {"transmission_it_sdi_codice_fiscale", "transmission_it_sdi_pec", "transmission_it_sdi_recipient_code"}
+        return {"transmission_it_sdi_codice_fiscale", "transmission_it_sdi_pec"}
+
+    def invoice_address_form_fields_required(self, country: Country, is_business: bool):
+        base = {
+            "street", "zipcode", "city", "state", "country",
+        }
+        if is_business:
+            return base | {"company", "vat_id", "transmission_it_sdi_pec", "transmission_it_sdi_recipient_code"}
+        return base | {"transmission_it_sdi_codice_fiscale"}
+
+    def pdf_info_text(self) -> str:
+        # Watermark is not necessary as this is a usual precaution in Italy
+        return pgettext(
+            "italian_invoice",
+            "This PDF document is a visual copy of the invoice and does not constitute an invoice for VAT "
+            "purposes. The invoice is issued in XML format, transmitted in accordance with the procedures and terms "
+            "set forth in No. 89757/2018 of April 30, 2018, issued by the Director of the Revenue Agency."
+        )

src/pretix/base/invoicing/peppol.py

@@ -0,0 +1,177 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+import re
+
+from django import forms
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext_lazy as _, pgettext
+from django_countries.fields import Country
+
+from pretix.base.invoicing.transmission import (
+    TransmissionType, transmission_types,
+)
+
+
+class PeppolIdValidator:
+    regex_rules = {
+        # Source: https://docs.peppol.eu/edelivery/codelists/old/v8.5/Peppol%20Code%20Lists%20-%20Participant%20identifier%20schemes%20v8.5.html
+        "0002": "[0-9]{9}([0-9]{5})?",
+        "0007": "[0-9]{10}",
+        "0009": "[0-9]{14}",
+        "0037": "(0037)?[0-9]{7}-?[0-9][0-9A-Z]{0,5}",
+        "0060": "[0-9]{9}",
+        "0088": "[0-9]{13}",
+        "0096": "[0-9]{17}",
+        "0097": "[0-9]{11,16}",
+        "0106": "[0-9]{17}",
+        "0130": ".*",
+        "0135": ".*",
+        "0142": ".*",
+        "0151": "[0-9]{11}",
+        "0183": "CHE[0-9]{9}",
+        "0184": "DK[0-9]{8}([0-9]{2})?",
+        "0188": ".*",
+        "0190": "[0-9]{20}",
+        "0191": "[1789][0-9]{7}",
+        "0192": "[0-9]{9}",
+        "0193": ".{4,50}",
+        "0195": "[a-z]{2}[a-z]{3}([0-9]{8}|[0-9]{9}|[RST][0-9]{2}[a-z]{2}[0-9]{4})[0-9a-z]",
+        "0196": "[0-9]{10}",
+        "0198": "DK[0-9]{8}",
+        "0199": "[A-Z0-9]{18}[0-9]{2}",
+        "0020": "[0-9]{9}",
+        "0201": "[0-9a-zA-Z]{6}",
+        "0204": "[0-9]{2,12}(-[0-9A-Z]{0,30})?-[0-9]{2}",
+        "0208": "0[0-9]{9}",
+        "0209": ".*",
+        "0210": "[A-Z0-9]+",
+        "0211": "IT[0-9]{11}",
+        "0212": "[0-9]{7}-[0-9]",
+        "0213": "FI[0-9]{8}",
+        "0205": "[A-Z0-9]+",
+        "0221": "T[0-9]{13}",
+        "0230": ".*",
+        "9901": ".*",
+        "9902": "[1-9][0-9]{7}",
+        "9904": "DK[0-9]{8}",
+        "9909": "NO[0-9]{9}MVA",
+        "9910": "HU[0-9]{8}",
+        "9912": "[A-Z]{2}[A-Z0-9]{,20}",
+        "9913": ".*",
+        "9914": "ATU[0-9]*",
+        "9915": "[A-Z][A-Z0-9]*",
+        "9916": ".*",
+        "9917": "[0-9]{10}",
+        "9918": "[A-Z]{2}[0-9]{2}[A-Z-0-9]{11,30}",
+        "9919": "[A-Z][0-9]{3}[A-Z][0-9]{3}[A-Z]",
+        "9920": ".*",
+        "9921": ".*",
+        "9922": ".*",
+        "9923": ".*",
+        "9924": ".*",
+        "9925": ".*",
+        "9926": ".*",
+        "9927": ".*",
+        "9928": ".*",
+        "9929": ".*",
+        "9930": ".*",
+        "9931": ".*",
+        "9932": ".*",
+        "9933": ".*",
+        "9934": ".*",
+        "9935": ".*",
+        "9936": ".*",
+        "9937": ".*",
+        "9938": ".*",
+        "9939": ".*",
+        "9940": ".*",
+        "9941": ".*",
+        "9942": ".*",
+        "9943": ".*",
+        "9944": ".*",
+        "9945": ".*",
+        "9946": ".*",
+        "9947": ".*",
+        "9948": ".*",
+        "9949": ".*",
+        "9950": ".*",
+        "9951": ".*",
+        "9952": ".*",
+        "9953": ".*",
+        "9954": ".*",
+        "9956": "0[0-9]{9}",
+        "9957": ".*",
+        "9959": ".*",
+    }
+
+    def __call__(self, value):
+        if ":" not in value:
+            raise ValidationError(_("A Peppol participant ID always starts with a prefix, followed by a colon (:)."))
+
+        prefix, second = value.split(":", 1)
+        if prefix not in self.regex_rules:
+            raise ValidationError(_("The Peppol participant ID prefix %(number)s is not known to our system. Please "
+                                    "reach out to us if you are sure this ID is correct."), params={"number": prefix})
+
+        if not re.match(self.regex_rules[prefix], second):
+            raise ValidationError(_("The Peppol participant ID does not match the validation rules for the prefix "
+                                    "%(number)s. Please reach out to us if you are sure this ID is correct."),
+                                  params={"number": prefix})
+        return value
+
+
+@transmission_types.new()
+class PeppolTransmissionType(TransmissionType):
+    identifier = "peppol"
+    verbose_name = "Peppol"
+    priority = 250
+    enforce_transmission = True
+
+    def is_available(self, event, country: Country, is_business: bool):
+        return is_business and super().is_available(event, country, is_business)
+
+    @property
+    def invoice_address_form_fields(self) -> dict:
+        return {
+            "transmission_peppol_participant_id": forms.CharField(
+                label=_("Peppol participant ID"),
+                validators=[
+                    PeppolIdValidator(),
+                ]
+            ),
+        }
+
+    def invoice_address_form_fields_required(self, country: Country, is_business: bool):
+        base = {
+            "company", "street", "zipcode", "city", "country",
+        }
+        return base | {"transmission_peppol_participant_id"}
+
+    def pdf_watermark(self) -> str:
+        return pgettext("peppol_invoice", "Visual copy")
+
+    def pdf_info_text(self) -> str:
+        return pgettext(
+            "peppol_invoice",
+            "This PDF document is a visual copy of the invoice and does not constitute an invoice for VAT "
+            "purposes. The original invoice is issued in XML format and transmitted through the Peppol network."
+        )

src/pretix/base/invoicing/transmission.py

@@ -0,0 +1,258 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+from typing import Optional
+
+from django_countries.fields import Country
+
+from pretix.base.models import Invoice, InvoiceAddress
+from pretix.base.signals import EventPluginRegistry, Registry
+
+
+class TransmissionType:
+    @property
+    def identifier(self) -> str:
+        """
+        A short and unique identifier for this transmission type.
+        """
+        raise NotImplementedError
+
+    @property
+    def verbose_name(self) -> str:
+        """
+        A human-readable name for this transmission type to be shown internally in the backend.
+        """
+        raise NotImplementedError
+
+    @property
+    def public_name(self) -> str:
+        """
+        A human-readable name for this transmission type to be shown to the public.
+        By default, this is the same as ``verbose_name``
+        """
+        return self.verbose_name
+
+    @property
+    def priority(self) -> int:
+        """
+        Returns a priority that is used for sorting transmission type. Higher priority means higher up in the list.
+        Default to 100. Providers with same priority are sorted alphabetically.
+        """
+        return 100
+
+    @property
+    def exclusive(self) -> bool:
+        """
+        If a transmission type is exclusive, no other type can be chosen if this type is
+        available. Use e.g. if a certain transmission type is legally required in a certain
+        jurisdiction.
+        """
+        return False
+
+    @property
+    def enforce_transmission(self) -> bool:
+        """
+        If a transmission type enforces transmission, every invoice created with this type will be transferred.
+        If not, the backend user is in some cases trusted to decide whether or not to transmit it.
+        """
+        return False
+
+    def is_available(self, event, country: Country, is_business: bool) -> bool:
+        providers = transmission_providers.filter(type=self.identifier, active_in=event)
+        return any(
+            provider.is_available(event, country, is_business)
+            for provider, _ in providers
+        )
+
+    def invoice_address_form_fields_required(self, country: Country, is_business: bool):
+        return set()
+
+    def invoice_address_form_fields_visible(self, country: Country, is_business: bool) -> set:
+        return set(self.invoice_address_form_fields.keys())
+
+    def validate_address(self, ia: InvoiceAddress):
+        pass
+
+    @property
+    def invoice_address_form_fields(self) -> dict:
+        """
+        Return a set of form fields that **must** be prefixed with ``transmission_<identifier>_``.
+        """
+        return {}
+
+    def form_data_to_transmission_info(self, form_data: dict) -> dict:
+        return form_data
+
+    def transmission_info_to_form_data(self, transmission_info: dict) -> dict:
+        return transmission_info
+
+    def pdf_watermark(self) -> Optional[str]:
+        """
+        Return a watermark that should be rendered across the PDF file.
+        """
+        return None
+
+    def pdf_info_text(self) -> Optional[str]:
+        """
+        Return an info text that should be rendered on the PDF file.
+        """
+        return None
+
+
+class TransmissionProvider:
+    """
+    Base class for a transmission provider. Should NOT hold internal state as the class is only
+    instantiated once and then shared between events and organizers.
+    """
+
+    @property
+    def identifier(self):
+        """
+        A short and unique identifier for this transmission provider.
+        This should only contain lowercase letters and underscores.
+        """
+        raise NotImplementedError
+
+    @property
+    def type(self):
+        """
+        Identifier of the transmission type this provider provides.
+        """
+        raise NotImplementedError
+
+    @property
+    def verbose_name(self):
+        """
+        A human-readable name for this transmission provider (can be localized).
+        """
+        raise NotImplementedError
+
+    @property
+    def testmode_supported(self) -> bool:
+        """
+        Whether testmode invoices may be passed to this provider.
+        """
+        return False
+
+    def is_ready(self, event) -> bool:
+        """
+        Return whether this provider has all required configuration to be used in this event.
+        """
+        raise NotImplementedError
+
+    def is_available(self, event, country: Country, is_business: bool) -> bool:
+        """
+        Return whether this provider may be used for an invoice for the given recipient country and address type.
+        """
+        raise NotImplementedError
+
+    def transmit(self, invoice: Invoice):
+        """
+        Transmit the invoice. The invoice passed as a parameter will be in status ``TRANSMISSION_STATUS_INFLIGHT``.
+        Invoices that stay in this state for more than 24h will be retried automatically. Implementations are expected to:
+
+        - Send the invoice.
+
+        - Update the ``transmission_status`` to `TRANSMISSION_STATUS_COMPLETED` or `TRANSMISSION_STATUS_FAILED`
+          after sending, as well as ``transmission_info`` with provider-specific data, and ``transmission_date`` to
+          the date and time of completion.
+
+        - Create a log entry of action type ``pretix.event.order.invoice.sent`` or
+          ``pretix.event.order.invoice.sending_failed`` with the fields ``full_invoice_no``, ``transmission_provider``,
+          ``transmission_type`` and a provider-specific ``data`` field.
+
+        Make sure to either handle ``invoice.order.testmode`` properly or set ``testmode_supported`` to ``False``.
+        """
+        raise NotImplementedError
+
+    @property
+    def priority(self) -> int:
+        """
+        Returns a priority that is used for sorting transmission providers. Higher priority will be chosen over
+        lower priority for transmission. Default to 100.
+        """
+        return 100
+
+    def settings_url(self, event) -> Optional[str]:
+        """
+        Return a URL to the settings page of this provider (if any).
+        """
+        return None
+
+
+class TransmissionProviderRegistry(EventPluginRegistry):
+    def __init__(self):
+        super().__init__({
+            'identifier': lambda o: getattr(o, 'identifier'),
+            'type': lambda o: getattr(o, 'type'),
+        })
+
+    def register(self, *objs):
+        for obj in objs:
+            if not isinstance(obj, TransmissionProvider):
+                raise TypeError('Entries must be derived from TransmissionProvider')
+
+            if obj.type == "email" and not obj.__module__.startswith('pretix.base.'):
+                raise TypeError('No custom providers for email allowed')
+
+        return super().register(*objs)
+
+
+class TransmissionTypeRegistry(Registry):
+    def __init__(self):
+        super().__init__({
+            'identifier': lambda o: getattr(o, 'identifier'),
+        })
+
+    def register(self, *objs):
+        for obj in objs:
+            if not isinstance(obj, TransmissionType):
+                raise TypeError('Entries must be derived from TransmissionType')
+
+            if not obj.__module__.startswith('pretix.base.'):
+                raise TypeError('Plugins are currently not allowed to add transmission types')
+
+        return super().register(*objs)
+
+
+"""
+Registry for transmission providers.
+
+Each entry in this registry should be an instance of a subclass of ``TransmissionProvider``.
+They are annotated with their ``identifier``, ``type``, and the defining ``plugin``.
+"""
+transmission_providers = TransmissionProviderRegistry()
+
+
+"""
+Registry for transmission types.
+
+Each entry in this registry should be an instance of a subclass of ``TransmissionType``.
+They are annotated with their ``identifier``.
+"""
+transmission_types = TransmissionTypeRegistry()
+
+
+def get_transmission_types():
+    return sorted(
+        transmission_types.registered_entries.keys(),
+        key=lambda t: (-t.priority, str(t.public_name)),
+    )

src/pretix/base/logentrytype_registry.py

@@ -26,7 +26,7 @@ from django.urls import reverse
 from django.utils.html import format_html
 from django.utils.translation import gettext_lazy as _
 
-from pretix.base.signals import EventPluginRegistry
+from pretix.base.signals import PluginAwareRegistry
 
 
 def make_link(a_map, wrapper, is_active=True, event=None, plugin_name=None):
@@ -55,7 +55,7 @@ def make_link(a_map, wrapper, is_active=True, event=None, plugin_name=None):
         return format_html(wrapper, **a_map)
 
 
-class LogEntryTypeRegistry(EventPluginRegistry):
+class LogEntryTypeRegistry(PluginAwareRegistry):
     def __init__(self):
         super().__init__({'action_type': lambda o: getattr(o, 'action_type')})
 

src/pretix/base/logentrytypes.py

@@ -148,7 +148,7 @@ class TaxRuleLogEntryType(EventLogEntryType):
 
 
 class WaitingListEntryLogEntryType(EventLogEntryType):
-    object_link_wrapper = _('{val}')
+    object_link_wrapper = '{val}'
     object_link_viewname = 'control:event.orders.waitinglist'
     content_type = WaitingListEntry
 

src/pretix/base/management/commands/makemessages.py

@@ -0,0 +1,35 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+import re
+
+from django.core.management.commands import makemessages
+
+
+def is_valid_locale(locale):
+    return re.match(r"^[a-z]+$", locale) or re.match(r"^[a-z]+_[A-Z0-9].*$", locale)
+
+
+makemessages.is_valid_locale = is_valid_locale
+
+
+class Command(makemessages.Command):
+    pass

src/pretix/base/management/commands/runperiodic.py

@@ -38,6 +38,7 @@ import traceback
 from django.conf import settings
 from django.core.cache import cache
 from django.core.management.base import BaseCommand
+from django.db import close_old_connections
 from django.dispatch.dispatcher import NO_RECEIVERS
 
 from pretix.helpers.periodic import SKIPPED
@@ -79,6 +80,8 @@ class Command(BaseCommand):
                 self.stdout.write(f'INFO Running {name}…')
             t0 = time.time()
             try:
+                # Check if the DB connection is still good, it might be closed if the previous task took too long.
+                close_old_connections()
                 r = receiver(signal=periodic_task, sender=self)
             except Exception as err:
                 if isinstance(err, KeyboardInterrupt):

src/pretix/base/migrations/0282_taxrule_default.py

@@ -0,0 +1,24 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixbase", "0281_event_is_remote"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="taxrule",
+            name="default",
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AddConstraint(
+            model_name="taxrule",
+            constraint=models.UniqueConstraint(
+                condition=models.Q(("default", True)),
+                fields=("event",),
+                name="one_default_per_event",
+            ),
+        ),
+    ]

src/pretix/base/migrations/0283_taxrule_default_taxrule_backfill.py

@@ -0,0 +1,60 @@
+# Generated by Django 4.2.17 on 2025-03-28 09:19
+from django.core.cache import cache
+from django.db import migrations, models
+from django.db.models import Count, Exists, OuterRef
+
+
+def set_default_tax_rate(app, schema_editor):
+    Event = app.get_model('pretixbase', 'Event')
+    Event_SettingsStore = app.get_model('pretixbase', 'Event_SettingsStore')
+    TaxRule = app.get_model('pretixbase', 'TaxRule')
+
+    # Handling of events with tax_rate_default set
+    for s in Event_SettingsStore.objects.filter(key="tax_rate_default").iterator():
+        updated = TaxRule.objects.filter(pk=s.value, event_id=s.object_id).update(default=True)
+        if updated:
+            # Delete deprecated settings key
+            s.delete()
+
+            # The default for new events is tax_rule_cancellation=none, but since we do not change behaviour
+            # for existing events without warning, we create a settings entry that matches the old behaviour.
+            Event_SettingsStore.objects.get_or_create(
+                object_id=s.object_id,
+                key="tax_rule_cancellation",
+                defaults={"value": "default"},
+            )
+
+            # We do not need to set tax_rule_payment here since "default" is the default
+
+            cache.delete('hierarkey_{}_{}'.format('event', s.object_id))
+
+    # Handling of events with tax_rate_default not set
+    for e in Event.objects.only("pk").exclude(Exists(TaxRule.objects.filter(default=True, event_id=OuterRef("pk")))).iterator():
+        fav_tax_rules = e.tax_rules.annotate(c=Count("item")).order_by("-c", "pk")[:1]
+        if fav_tax_rules:
+            fav_tax_rules[0].default = True
+            fav_tax_rules[0].save()
+
+        # Previously, no tax rule was set for payments, so keep it this way
+        Event_SettingsStore.objects.get_or_create(
+            object=e,
+            key="tax_rule_payment",
+            defaults={"value": "none"},
+        )
+        cache.delete('hierarkey_{}_{}'.format('event', e.pk))
+
+        # We do not need to set tax_rule_cancellation, as "none" is the new system default
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixbase", "0282_taxrule_default"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            set_default_tax_rate,
+            migrations.RunPython.noop,
+        ),
+    ]

src/pretix/base/migrations/0284_ordersyncresult_ordersyncqueue.py

@@ -0,0 +1,54 @@
+# Generated by Django 4.2.21 on 2025-06-27 13:32
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0283_taxrule_default_taxrule_backfill'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='OrderSyncResult',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False)),
+                ('sync_provider', models.CharField(max_length=128)),
+                ('mapping_id', models.IntegerField()),
+                ('external_object_type', models.CharField(max_length=128)),
+                ('external_id_field', models.CharField(max_length=128)),
+                ('id_value', models.CharField(max_length=128)),
+                ('external_link_href', models.CharField(max_length=255, null=True)),
+                ('external_link_display_name', models.CharField(max_length=255, null=True)),
+                ('transmitted', models.DateTimeField(auto_now_add=True)),
+                ('sync_info', models.JSONField()),
+                ('order', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='sync_results', to='pretixbase.order')),
+                ('order_position', models.ForeignKey(null=True, on_delete=django.db.models.deletion.CASCADE, related_name='sync_results', to='pretixbase.orderposition')),
+            ],
+            options={
+                'indexes': [models.Index(fields=['order', 'sync_provider'], name='pretixbase__order_i_3e3c84_idx')],
+            },
+        ),
+        migrations.CreateModel(
+            name='OrderSyncQueue',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False)),
+                ('sync_provider', models.CharField(max_length=128)),
+                ('triggered_by', models.CharField(max_length=128)),
+                ('triggered', models.DateTimeField(auto_now_add=True)),
+                ('failed_attempts', models.PositiveIntegerField(default=0)),
+                ('not_before', models.DateTimeField(db_index=True)),
+                ('need_manual_retry', models.CharField(null=True, max_length=20)),
+                ('in_flight', models.BooleanField(default=False)),
+                ('in_flight_since', models.DateTimeField(blank=True, null=True)),
+                ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='queued_sync_jobs', to='pretixbase.event')),
+                ('order', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='queued_sync_jobs', to='pretixbase.order')),
+            ],
+            options={
+                'ordering': ('triggered',),
+                'unique_together': {('order', 'sync_provider', 'in_flight')},
+            },
+        ),
+    ]

src/pretix/base/migrations/0285_voucher_created.py

@@ -0,0 +1,46 @@
+# Generated by Django 4.2.16 on 2025-08-08 09:13
+
+from django.db import migrations, models
+from django.db.models import Min
+from django.utils.timezone import now
+
+
+def backfill_voucher_created(apps, schema_editor):
+    Voucher = apps.get_model("pretixbase", "Voucher")
+    LogEntry = apps.get_model("pretixbase", "LogEntry")
+    ContentType = apps.get_model("contenttypes", "ContentType")
+    ct = None
+
+    for v in Voucher.objects.filter(created__isnull=True).iterator():
+        if not ct:
+            # "Lazy-loading" to prevent this to be executed on new DBs where the content type does not yet
+            # exist -- but also no vouchers do
+            ct = ContentType.objects.get(app_label='pretixbase', model='voucher')
+        v.created = LogEntry.objects.filter(
+            content_type=ct,
+            object_id=v.pk,
+        ).aggregate(m=Min("datetime"))["m"] or now()
+        v.save(update_fields=["created"])
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("pretixbase", "0284_ordersyncresult_ordersyncqueue"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="voucher",
+            name="created",
+            field=models.DateTimeField(auto_now_add=True, null=True),
+        ),
+        migrations.RunPython(
+            backfill_voucher_created,
+            migrations.RunPython.noop,
+        ),
+        migrations.AlterField(
+            model_name="voucher",
+            name="created",
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+    ]

src/pretix/base/migrations/0286_settingsstore_unique.py

@@ -0,0 +1,28 @@
+# Generated by Django 4.2.16 on 2025-08-14 09:40
+
+from django.db import migrations
+from hierarkey.utils import CleanHierarkeyDuplicates
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("pretixbase", "0285_voucher_created"),
+    ]
+
+    operations = [
+        CleanHierarkeyDuplicates("GlobalSettingsObject_SettingsStore"),
+        CleanHierarkeyDuplicates("Organizer_SettingsStore"),
+        CleanHierarkeyDuplicates("Event_SettingsStore"),
+        migrations.AlterUniqueTogether(
+            name="event_settingsstore",
+            unique_together={("object", "key")},
+        ),
+        migrations.AlterUniqueTogether(
+            name="globalsettingsobject_settingsstore",
+            unique_together={("key",)},
+        ),
+        migrations.AlterUniqueTogether(
+            name="organizer_settingsstore",
+            unique_together={("object", "key")},
+        ),
+    ]

src/pretix/base/migrations/0287_organizer_plugins.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.2.17 on 2025-07-12 09:25
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixbase", "0286_settingsstore_unique"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="organizer",
+            name="plugins",
+            field=models.TextField(default=""),
+        ),
+    ]

src/pretix/base/migrations/0288_invoice_transmission.py

@@ -0,0 +1,75 @@
+# Generated by Django 4.2.17 on 2025-04-21 11:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixbase", "0287_organizer_plugins"),
+    ]
+
+    operations = [
+        migrations.RenameField(
+            model_name="invoice",
+            old_name="sent_to_customer",
+            new_name="transmission_date",
+        ),
+        migrations.AddField(
+            model_name="invoice",
+            name="invoice_to_transmission_info",
+            field=models.JSONField(null=True),
+        ),
+        migrations.AddField(
+            model_name="invoice",
+            name="transmission_info",
+            field=models.JSONField(null=True),
+        ),
+        migrations.AddField(
+            model_name="invoice",
+            name="transmission_provider",
+            field=models.CharField(max_length=255, null=True),
+        ),
+        migrations.AddField(
+            model_name="invoice",
+            name="transmission_status",
+            field=models.CharField(default="unknown", max_length=255),
+        ),
+        migrations.AddField(
+            model_name="invoice",
+            name="created",
+            field=models.DateTimeField(auto_now_add=True, null=True),
+        ),
+        migrations.AddField(
+            model_name="invoice",
+            name="invoice_to_is_business",
+            field=models.BooleanField(null=True),
+        ),
+        migrations.RunSQL(
+            "UPDATE pretixbase_invoice SET transmission_status = 'completed' WHERE transmission_date IS NOT NULL",
+            migrations.RunSQL.noop,
+        ),
+        migrations.AddField(
+            model_name="invoice",
+            name="transmission_type",
+            field=models.CharField(default="email", max_length=255),
+        ),
+        migrations.AddField(
+            model_name="invoiceaddress",
+            name="transmission_info",
+            field=models.JSONField(null=True),
+        ),
+        migrations.AddField(
+            model_name="invoiceaddress",
+            name="transmission_type",
+            field=models.CharField(default="email", max_length=255),
+        ),
+        migrations.RunSQL(
+            "UPDATE pretixbase_event_settingsstore SET key = 'mail_text_order_invoice' WHERE key = 'payment_banktransfer_invoice_email_text'",
+            "UPDATE pretixbase_event_settingsstore SET key = 'payment_banktransfer_invoice_email_text' WHERE key = 'mail_text_order_invoice'",
+        ),
+        migrations.RunSQL(
+            "UPDATE pretixbase_event_settingsstore SET key = 'mail_subject_order_invoice' WHERE key = 'payment_banktransfer_invoice_email_subject'",
+            "UPDATE pretixbase_event_settingsstore SET key = 'payment_banktransfer_invoice_email_subject' WHERE key = 'mail_subject_order_invoice'",
+        ),
+    ]

src/pretix/base/modelimport.py

@@ -111,6 +111,13 @@ class ImportColumn:
         """
         return gettext_lazy('Keep empty')
 
+    @property
+    def help_text(self):
+        """
+        Additional description of the column
+        """
+        return None
+
     def __init__(self, event):
         self.event = event
 

src/pretix/base/modelimport_orders.py

@@ -57,6 +57,7 @@ from pretix.base.signals import order_import_columns
 class EmailColumn(ImportColumn):
     identifier = 'email'
     verbose_name = gettext_lazy('Email address')
+    order_level = True
 
     def clean(self, value, previous_values):
         if value:
@@ -67,9 +68,24 @@ class EmailColumn(ImportColumn):
         order.email = value
 
 
+class GroupingColumn(ImportColumn):
+    identifier = 'grouping'
+    verbose_name = gettext_lazy('Grouping')
+    help_text = gettext_lazy(
+        'Only applicable when "Import mode" is set to "Group multiple lines together...". Lines with the same grouping '
+        'value will be put in the same order, but MUST be consecutive lines of the input file.'
+    )
+    order_level = True
+    default_label = "---"
+
+    def assign(self, value, order, position, invoice_address, **kwargs):
+        pass
+
+
 class PhoneColumn(ImportColumn):
     identifier = 'phone'
     verbose_name = gettext_lazy('Phone number')
+    order_level = True
 
     def clean(self, value, previous_values):
         if value:
@@ -94,6 +110,10 @@ class SubeventColumn(SubeventColumnMixin, ImportColumn):
     identifier = 'subevent'
     verbose_name = pgettext_lazy('subevents', 'Date')
     default_value = None
+    help_text = pgettext_lazy(
+        'subevents', 'The date can be specified through its full name, full date and time, or internal ID, provided '
+                     'only one date in the system matches the input.'
+    )
 
     def clean(self, value, previous_values):
         if not value:
@@ -108,6 +128,7 @@ class ItemColumn(ImportColumn):
     identifier = 'item'
     verbose_name = gettext_lazy('Product')
     default_value = None
+    help_text = gettext_lazy('The product can be specified by its internal ID, full name or internal name.')
 
     @cached_property
     def items(self):
@@ -137,6 +158,7 @@ class ItemColumn(ImportColumn):
 class Variation(ImportColumn):
     identifier = 'variation'
     verbose_name = gettext_lazy('Product variation')
+    help_text = gettext_lazy('The variation can be specified by its internal ID or full name.')
 
     @cached_property
     def items(self):
@@ -170,6 +192,7 @@ class Variation(ImportColumn):
 
 class InvoiceAddressCompany(ImportColumn):
     identifier = 'invoice_address_company'
+    order_level = True
 
     @property
     def verbose_name(self):
@@ -181,6 +204,8 @@ class InvoiceAddressCompany(ImportColumn):
 
 
 class InvoiceAddressNamePart(ImportColumn):
+    order_level = True
+
     def __init__(self, event, key, label):
         self.key = key
         self.label = label
@@ -200,6 +225,7 @@ class InvoiceAddressNamePart(ImportColumn):
 
 class InvoiceAddressStreet(ImportColumn):
     identifier = 'invoice_address_street'
+    order_level = True
 
     @property
     def verbose_name(self):
@@ -211,6 +237,7 @@ class InvoiceAddressStreet(ImportColumn):
 
 class InvoiceAddressZip(ImportColumn):
     identifier = 'invoice_address_zipcode'
+    order_level = True
 
     @property
     def verbose_name(self):
@@ -222,6 +249,7 @@ class InvoiceAddressZip(ImportColumn):
 
 class InvoiceAddressCity(ImportColumn):
     identifier = 'invoice_address_city'
+    order_level = True
 
     @property
     def verbose_name(self):
@@ -234,6 +262,8 @@ class InvoiceAddressCity(ImportColumn):
 class InvoiceAddressCountry(ImportColumn):
     identifier = 'invoice_address_country'
     default_value = None
+    help_text = gettext_lazy('The country needs to be specified using a two-letter country code.')
+    order_level = True
 
     @property
     def initial(self):
@@ -257,6 +287,8 @@ class InvoiceAddressCountry(ImportColumn):
 
 class InvoiceAddressState(ImportColumn):
     identifier = 'invoice_address_state'
+    help_text = gettext_lazy('The state can be specified by its short form or full name.')
+    order_level = True
 
     @property
     def verbose_name(self):
@@ -282,6 +314,7 @@ class InvoiceAddressState(ImportColumn):
 
 class InvoiceAddressVATID(ImportColumn):
     identifier = 'invoice_address_vat_id'
+    order_level = True
 
     @property
     def verbose_name(self):
@@ -293,6 +326,7 @@ class InvoiceAddressVATID(ImportColumn):
 
 class InvoiceAddressReference(ImportColumn):
     identifier = 'invoice_address_internal_reference'
+    order_level = True
 
     @property
     def verbose_name(self):
@@ -380,6 +414,7 @@ class AttendeeCity(ImportColumn):
 class AttendeeCountry(ImportColumn):
     identifier = 'attendee_country'
     default_value = None
+    help_text = gettext_lazy('The country needs to be specified using a two-letter country code.')
 
     @property
     def initial(self):
@@ -403,6 +438,7 @@ class AttendeeCountry(ImportColumn):
 
 class AttendeeState(ImportColumn):
     identifier = 'attendee_state'
+    help_text = gettext_lazy('The state can be specified by its short form or full name.')
 
     @property
     def verbose_name(self):
@@ -471,6 +507,7 @@ class Locale(ImportColumn):
     identifier = 'locale'
     verbose_name = gettext_lazy('Order locale')
     default_value = None
+    order_level = True
 
     @property
     def initial(self):
@@ -514,6 +551,7 @@ class ValidUntil(DatetimeColumnMixin, ImportColumn):
 class Expires(DatetimeColumnMixin, ImportColumn):
     identifier = 'expires'
     verbose_name = gettext_lazy('Expiry date')
+    order_level = True
 
     def clean(self, value, previous_values):
         if not value:
@@ -540,6 +578,8 @@ class Saleschannel(ImportColumn):
     verbose_name = gettext_lazy('Sales channel')
     default_value = None
     initial = 'static:web'
+    help_text = gettext_lazy('The sales channel can be specified by it\'s internal identifier or its full name.')
+    order_level = True
 
     @cached_property
     def channels(self):
@@ -568,6 +608,7 @@ class Saleschannel(ImportColumn):
 class SeatColumn(ImportColumn):
     identifier = 'seat'
     verbose_name = gettext_lazy('Seat ID')
+    help_text = gettext_lazy('The seat needs to be specified by its internal ID.')
 
     def __init__(self, *args):
         self._cached = set()
@@ -599,7 +640,8 @@ class SeatColumn(ImportColumn):
 
 class Comment(ImportColumn):
     identifier = 'comment'
-    verbose_name = gettext_lazy('Comment')
+    verbose_name = gettext_lazy('Order comment')
+    order_level = True
 
     def assign(self, value, order, position, invoice_address, **kwargs):
         order.comment = value or ''
@@ -608,6 +650,7 @@ class Comment(ImportColumn):
 class CheckinAttentionColumn(BooleanColumnMixin, ImportColumn):
     identifier = 'checkin_attention'
     verbose_name = gettext_lazy('Requires special attention')
+    order_level = True
 
     def assign(self, value, order, position, invoice_address, **kwargs):
         order.checkin_attention = value
@@ -616,6 +659,7 @@ class CheckinAttentionColumn(BooleanColumnMixin, ImportColumn):
 class CheckinTextColumn(ImportColumn):
     identifier = 'checkin_text'
     verbose_name = gettext_lazy('Check-in text')
+    order_level = True
 
     def assign(self, value, order, position, invoice_address, **kwargs):
         order.checkin_text = value
@@ -696,6 +740,7 @@ class QuestionColumn(ImportColumn):
 class CustomerColumn(ImportColumn):
     identifier = 'customer'
     verbose_name = gettext_lazy('Customer')
+    order_level = True
 
     def clean(self, value, previous_values):
         if value:
@@ -720,6 +765,7 @@ def get_order_import_columns(event):
     if event.has_subevents:
         default.append(SubeventColumn(event))
     default += [
+        GroupingColumn(event),
         EmailColumn(event),
         PhoneColumn(event),
         ItemColumn(event),

src/pretix/base/models/checkin.py

@@ -350,6 +350,7 @@ class Checkin(models.Model):
     REASON_BLOCKED = 'blocked'
     REASON_UNAPPROVED = 'unapproved'
     REASON_INVALID_TIME = 'invalid_time'
+    REASON_ANNULLED = 'annulled'
     REASONS = (
         (REASON_CANCELED, _('Order canceled')),
         (REASON_INVALID, _('Unknown ticket')),
@@ -364,6 +365,7 @@ class Checkin(models.Model):
         (REASON_BLOCKED, _('Ticket blocked')),
         (REASON_UNAPPROVED, _('Order not approved')),
         (REASON_INVALID_TIME, _('Ticket not valid at this time')),
+        (REASON_ANNULLED, _('Check-in annulled')),
     )
 
     successful = models.BooleanField(

src/pretix/base/models/datasync.py

@@ -0,0 +1,149 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+import logging
+from functools import cached_property
+
+from django.db import IntegrityError, models
+from django.utils.translation import gettext as _
+
+from pretix.base.models import Event, Order, OrderPosition
+
+logger = logging.getLogger(__name__)
+
+
+MODE_OVERWRITE = "overwrite"
+MODE_SET_IF_NEW = "if_new"
+MODE_SET_IF_EMPTY = "if_empty"
+MODE_APPEND_LIST = "append"
+
+
+class OrderSyncQueue(models.Model):
+    order = models.ForeignKey(
+        Order, on_delete=models.CASCADE, related_name="queued_sync_jobs"
+    )
+    event = models.ForeignKey(
+        Event, on_delete=models.CASCADE, related_name="queued_sync_jobs"
+    )
+    sync_provider = models.CharField(blank=False, null=False, max_length=128)
+    triggered_by = models.CharField(blank=False, null=False, max_length=128)
+    triggered = models.DateTimeField(blank=False, null=False, auto_now_add=True)
+    failed_attempts = models.PositiveIntegerField(default=0)
+    not_before = models.DateTimeField(blank=False, null=False, db_index=True)
+    need_manual_retry = models.CharField(blank=True, null=True, max_length=20, choices=[
+        ('exceeded', _('Temporary error, auto-retry limit exceeded')),
+        ('permanent', _('Provider reported a permanent error')),
+        ('config', _('Misconfiguration, please check provider settings')),
+        ('internal', _('System error, needs manual intervention')),
+        ('timeout', _('System error, needs manual intervention')),
+    ])
+    in_flight = models.BooleanField(default=False)
+    in_flight_since = models.DateTimeField(blank=True, null=True)
+
+    class Meta:
+        unique_together = (("order", "sync_provider", "in_flight"),)
+        ordering = ("triggered",)
+
+    @cached_property
+    def _provider_class_info(self):
+        from pretix.base.datasync.datasync import datasync_providers
+        return datasync_providers.get(identifier=self.sync_provider)
+
+    @property
+    def provider_class(self):
+        return self._provider_class_info[0]
+
+    @property
+    def provider_display_name(self):
+        return self.provider_class.display_name
+
+    @property
+    def is_provider_active(self):
+        return self._provider_class_info[1]
+
+    @property
+    def max_retry_attempts(self):
+        return self.provider_class.max_attempts
+
+    def set_sync_error(self, failure_mode, messages, full_message):
+        logger.exception(
+            f"Could not sync order {self.order.code} to {type(self).__name__} ({failure_mode})"
+        )
+        self.order.log_action(f"pretix.event.order.data_sync.failed.{failure_mode}", {
+            "provider": self.sync_provider,
+            "error": messages,
+            "full_message": full_message,
+        })
+        self.need_manual_retry = failure_mode
+        self.clear_in_flight()
+
+    def clear_in_flight(self):
+        self.in_flight = False
+        self.in_flight_since = None
+        try:
+            self.save()
+        except IntegrityError:
+            # if setting in_flight=False fails due to UNIQUE constraint, just delete the current instance
+            self.delete()
+
+
+class OrderSyncResult(models.Model):
+    order = models.ForeignKey(
+        Order, on_delete=models.CASCADE, related_name="sync_results"
+    )
+    sync_provider = models.CharField(blank=False, null=False, max_length=128)
+    order_position = models.ForeignKey(
+        OrderPosition, on_delete=models.CASCADE, related_name="sync_results", blank=True, null=True,
+    )
+    mapping_id = models.IntegerField(blank=False, null=False)
+    external_object_type = models.CharField(blank=False, null=False, max_length=128)
+    external_id_field = models.CharField(blank=False, null=False, max_length=128)
+    id_value = models.CharField(blank=False, null=False, max_length=128)
+    external_link_href = models.CharField(blank=True, null=True, max_length=255)
+    external_link_display_name = models.CharField(blank=True, null=True, max_length=255)
+    transmitted = models.DateTimeField(blank=False, null=False, auto_now_add=True)
+    sync_info = models.JSONField()
+
+    class Meta:
+        indexes = [
+            models.Index(fields=("order", "sync_provider")),
+        ]
+
+    def external_link_html(self):
+        if not self.external_link_display_name:
+            return None
+
+        from pretix.base.datasync.datasync import datasync_providers
+        prov, meta = datasync_providers.get(identifier=self.sync_provider)
+        if prov:
+            return prov.get_external_link_html(self.order.event, self.external_link_href, self.external_link_display_name)
+
+    def to_result_dict(self):
+        return {
+            "position": self.order_position_id,
+            "object_type": self.external_object_type,
+            "external_id_field": self.external_id_field,
+            "id_value": self.id_value,
+            "external_link_href": self.external_link_href,
+            "external_link_display_name": self.external_link_display_name,
+            **self.sync_info,
+        }

src/pretix/base/models/event.py

@@ -243,8 +243,16 @@ class EventMixin:
     def waiting_list_active(self):
         if not self.settings.waiting_list_enabled:
             return False
+
         if self.settings.waiting_list_auto_disable:
-            return self.settings.waiting_list_auto_disable.datetime(self) > time_machine_now()
+            if self.settings.waiting_list_auto_disable.datetime(self) <= time_machine_now():
+                return False
+
+        if hasattr(self, 'active_quotas'):
+            # Only run when called with computed quotas, i.e. event calendar
+            if not self.best_availability[3]:
+                return False
+
         return True
 
     @property
@@ -322,9 +330,7 @@ class EventMixin:
         sq_active_item = Item.objects.using(settings.DATABASE_REPLICA).filter_available(channel=channel, voucher=voucher).filter(
             Q(variations__isnull=True)
             & Q(quotas__pk=OuterRef('pk'))
-        ).order_by().values_list('quotas__pk').annotate(
-            items=GroupConcat('pk', delimiter=',')
-        ).values('items')
+        )
 
         q_variation = (
             Q(active=True)
@@ -357,9 +363,7 @@ class EventMixin:
             q_variation &= Q(hide_without_voucher=False)
             q_variation &= Q(item__hide_without_voucher=False)
 
-        sq_active_variation = ItemVariation.objects.filter(q_variation).order_by().values_list('quotas__pk').annotate(
-            items=GroupConcat('pk', delimiter=',')
-        ).values('items')
+        sq_active_variation = ItemVariation.objects.filter(q_variation)
         quota_base_qs = Quota.objects.using(settings.DATABASE_REPLICA).filter(
             ignore_for_event_availability=False
         )
@@ -376,8 +380,23 @@ class EventMixin:
                 'quotas',
                 to_attr='active_quotas',
                 queryset=quota_base_qs.annotate(
-                    active_items=Subquery(sq_active_item, output_field=models.TextField()),
-                    active_variations=Subquery(sq_active_variation, output_field=models.TextField()),
+                    active_items=Subquery(
+                        sq_active_item.order_by().values_list('quotas__pk').annotate(
+                            items=GroupConcat('pk', delimiter=',')
+                        ).values('items'),
+                        output_field=models.TextField()
+                    ),
+                    active_variations=Subquery(
+                        sq_active_variation.order_by().values_list('quotas__pk').annotate(
+                            items=GroupConcat('pk', delimiter=',')
+                        ).values('items'),
+                        output_field=models.TextField()),
+                    has_active_items_with_waitinglist=Exists(
+                        sq_active_item.filter(allow_waitinglist=True),
+                    ),
+                    has_active_variations_with_waitinglist=Exists(
+                        sq_active_variation.filter(item__allow_waitinglist=True),
+                    ),
                 ).exclude(
                     Q(active_items="") & Q(active_variations="")
                 ).select_related('event', 'subevent')
@@ -406,11 +425,12 @@ class EventMixin:
     @cached_property
     def best_availability(self):
         """
-        Returns a 3-tuple of
+        Returns a 4-tuple of
 
         - The availability state of this event (one of the ``Quota.AVAILABILITY_*`` constants)
         - The number of tickets currently available (or ``None``)
         - The number of tickets "originally" available (or ``None``)
+        - Whether a sold out product has the waiting list enabled
 
         This can only be called on objects obtained through a queryset that has been passed through ``.annotated()``.
         """
@@ -433,6 +453,7 @@ class EventMixin:
         r = getattr(self, '_quota_cache', {})
         quotas_for_item = defaultdict(list)
         quotas_for_variation = defaultdict(list)
+        waiting_list_found = False
         for q in self.active_quotas:
             if q not in r:
                 r[q] = q.availability(allow_cache=True)
@@ -441,6 +462,8 @@ class EventMixin:
                 for item_id in q.active_items.split(","):
                     if item_id not in items_disabled:
                         quotas_for_item[item_id].append(q)
+            if q.has_active_items_with_waitinglist or q.has_active_variations_with_waitinglist:
+                waiting_list_found = True
             if q.active_variations:
                 for var_id in q.active_variations.split(","):
                     if var_id not in vars_disabled:
@@ -448,7 +471,7 @@ class EventMixin:
 
         if not self.active_quotas or (not quotas_for_item and not quotas_for_variation):
             # No item is enabled for this event, treat the event as "unknown"
-            return None, None, None
+            return None, None, None, waiting_list_found
 
         # We iterate over all items and variations and keep track of
         # - `best_state_found` - the best availability state we have seen so far. If one item is available, the event is available!
@@ -467,7 +490,7 @@ class EventMixin:
             quotas_that_are_not_unlimited = [q for q in quota_list if q.size is not None]
             if not quotas_that_are_not_unlimited:
                 # We found an unlimited ticket, no more need to do anything else
-                return Quota.AVAILABILITY_OK, None, None
+                return Quota.AVAILABILITY_OK, None, None, waiting_list_found
 
             if worst_state_for_ticket == Quota.AVAILABILITY_OK:
                 availability_of_this = min(max(0, r[q][1] - quota_used_for_found_tickets[q]) for q in quotas_that_are_not_unlimited)
@@ -481,7 +504,8 @@ class EventMixin:
                 quota_used_for_possible_tickets[q] += possible_of_this
 
             best_state_found = max(best_state_found, worst_state_for_ticket)
-        return best_state_found, num_tickets_found, num_tickets_possible
+
+        return best_state_found, num_tickets_found, num_tickets_possible, waiting_list_found
 
     def free_seats(self, ignore_voucher=None, sales_channel='web', include_blocked=False):
         assert isinstance(sales_channel, str) or sales_channel is None
@@ -551,8 +575,7 @@ class Event(EventMixin, LoggedModel):
     :type presale_end: datetime
     :param location: venue
     :type location: str
-    :param plugins: A comma-separated list of plugin names that are active for this
-                    event.
+    :param plugins: A comma-separated list of plugin names that are active for this event.
     :type plugins: str
     :param has_subevents: Enable event series functionality
     :type has_subevents: bool
@@ -1085,7 +1108,7 @@ class Event(EventMixin, LoggedModel):
             s.save(force_insert=True)
 
         valid_sales_channel_identifers = set(self.organizer.sales_channels.values_list("identifier", flat=True))
-        skip_settings = (
+        skip_settings = {
             'ticket_secrets_pretix_sig1_pubkey',
             'ticket_secrets_pretix_sig1_privkey',
             # no longer used, but we still don't need to copy them
@@ -1093,7 +1116,10 @@ class Event(EventMixin, LoggedModel):
             'presale_css_checksum',
             'presale_widget_css_file',
             'presale_widget_css_checksum',
-        )
+        } | {
+            # Some settings might already exist due to e.g. the timezone being special in the API
+            s.key for s in self.settings._objects.all()
+        }
         settings_to_save = []
         for s in other.settings._objects.all():
             if s.key in skip_settings:
@@ -1113,13 +1139,6 @@ class Event(EventMixin, LoggedModel):
                 newname = default_storage.save(fname, fi)
                 s.value = 'file://' + newname
                 settings_to_save.append(s)
-            elif s.key == 'tax_rate_default':
-                try:
-                    if int(s.value) in tax_map:
-                        s.value = tax_map.get(int(s.value)).pk
-                        settings_to_save.append(s)
-                except ValueError:
-                    pass
             elif s.key.startswith('payment_') and s.key.endswith('__restrict_to_sales_channels'):
                 data = other.settings._unserialize(s.value, as_type=list)
                 data = [ident for ident in data if ident in valid_sales_channel_identifers]
@@ -1198,6 +1217,10 @@ class Event(EventMixin, LoggedModel):
                 renderers[pp.identifier] = pp
         return renderers
 
+    @cached_property
+    def cached_default_tax_rule(self):
+        return self.tax_rules.filter(default=True).first()
+
     @cached_property
     def ticket_secret_generators(self) -> dict:
         """
@@ -1393,7 +1416,7 @@ class Event(EventMixin, LoggedModel):
         from pretix.base.plugins import get_all_plugins
 
         return {
-            p.module: p for p in get_all_plugins(self)
+            p.module: p for p in get_all_plugins(event=self)
             if not p.name.startswith('.') and getattr(p, 'visible', True)
         }
 
@@ -1412,12 +1435,20 @@ class Event(EventMixin, LoggedModel):
         self.plugins = ",".join(modules)
 
     def enable_plugin(self, module, allow_restricted=frozenset()):
+        """
+        Adds a plugin to the list of plugins, calling its ``installed`` hook (if available).
+        It is the caller's responsibility to save the event object.
+        """
         plugins_active = self.get_plugins()
         if module not in plugins_active:
             plugins_active.append(module)
             self.set_active_plugins(plugins_active, allow_restricted=allow_restricted)
 
     def disable_plugin(self, module):
+        """
+        Adds a plugin to the list of plugins, calling its ``uninstalled`` hook (if available).
+        It is the caller's responsibility to save the event object.
+        """
         plugins_active = self.get_plugins()
         if module in plugins_active:
             plugins_active.remove(module)

src/pretix/base/models/invoices.py

@@ -42,7 +42,8 @@ from django.db.models.functions import Cast
 from django.utils import timezone
 from django.utils.crypto import get_random_string
 from django.utils.functional import cached_property
-from django.utils.translation import pgettext
+from django.utils.timezone import now
+from django.utils.translation import gettext_lazy as _, pgettext
 from django_scopes import ScopedManager
 
 from pretix.base.settings import COUNTRIES_WITH_STATE_IN_ADDRESS
@@ -110,6 +111,21 @@ class Invoice(models.Model):
     :param file: The filename of the rendered invoice
     :type file: File
     """
+    TRANSMISSION_STATUS_PENDING = "pending"
+    TRANSMISSION_STATUS_INFLIGHT = "inflight"
+    TRANSMISSION_STATUS_COMPLETED = "completed"
+    TRANSMISSION_STATUS_FAILED = "failed"
+    TRANSMISSION_STATUS_UNKNOWN = "unknown"
+    TRANSMISSION_STATUS_TESTMODE_IGNORED = "testmode_ignored"
+    TRANSMISSION_STATUS_CHOICES = (
+        (TRANSMISSION_STATUS_PENDING, _("pending transmission")),
+        (TRANSMISSION_STATUS_INFLIGHT, _("currently being transmitted")),
+        (TRANSMISSION_STATUS_COMPLETED, _("transmitted")),
+        (TRANSMISSION_STATUS_FAILED, _("failed")),
+        (TRANSMISSION_STATUS_UNKNOWN, _("unknown")),
+        (TRANSMISSION_STATUS_TESTMODE_IGNORED, _("not transmitted due to test mode")),
+    )
+
     order = models.ForeignKey('Order', related_name='invoices', db_index=True, on_delete=models.CASCADE)
     organizer = models.ForeignKey('Organizer', related_name='invoices', db_index=True, on_delete=models.PROTECT)
     event = models.ForeignKey('Event', related_name='invoices', db_index=True, on_delete=models.CASCADE)
@@ -131,6 +147,7 @@ class Invoice(models.Model):
 
     invoice_to = models.TextField()
     invoice_to_company = models.TextField(null=True)
+    invoice_to_is_business = models.BooleanField(null=True)
     invoice_to_name = models.TextField(null=True)
     invoice_to_street = models.TextField(null=True)
     invoice_to_zipcode = models.CharField(max_length=190, null=True)
@@ -139,9 +156,11 @@ class Invoice(models.Model):
     invoice_to_country = FastCountryField(null=True)
     invoice_to_vat_id = models.TextField(null=True)
     invoice_to_beneficiary = models.TextField(null=True)
+    invoice_to_transmission_info = models.JSONField(null=True, blank=True)
     internal_reference = models.TextField(blank=True)
     custom_field = models.CharField(max_length=255, null=True)
 
+    created = models.DateTimeField(auto_now_add=True, null=True)  # null for backwards compatibility
     date = models.DateField(default=today)
     locale = models.CharField(max_length=50, default='en')
     introductory_text = models.TextField(blank=True)
@@ -158,14 +177,28 @@ class Invoice(models.Model):
 
     shredded = models.BooleanField(default=False)
 
-    # The field sent_to_organizer records whether this invocie was already sent to the organizer by a configured
+    # The field sent_to_organizer records whether this invoice was already sent to the organizer by a configured
     # mechanism such as email.
     # NULL: The cronjob that handles sending did not yet run.
     # True: The invoice was sent.
     # False: The invoice wasn't sent and never will, because sending was not configured at the time of the check.
     sent_to_organizer = models.BooleanField(null=True, blank=True)
 
-    sent_to_customer = models.DateTimeField(null=True, blank=True)
+    transmission_type = models.CharField(
+        max_length=255,
+        default="email",
+    )
+    transmission_provider = models.CharField(
+        max_length=255,
+        null=True, blank=True,
+    )
+    transmission_status = models.CharField(
+        max_length=255,
+        choices=TRANSMISSION_STATUS_CHOICES,
+        default=TRANSMISSION_STATUS_UNKNOWN,
+    )
+    transmission_date = models.DateTimeField(null=True, blank=True)
+    transmission_info = models.JSONField(null=True, blank=True)
 
     file = models.FileField(null=True, blank=True, upload_to=invoice_filename, max_length=255)
 
@@ -323,6 +356,35 @@ class Invoice(models.Model):
     def __str__(self):
         return self.full_invoice_no
 
+    @property
+    def regenerate_allowed(self):
+        return self.transmission_status in (
+            Invoice.TRANSMISSION_STATUS_UNKNOWN,
+            Invoice.TRANSMISSION_STATUS_PENDING,
+            Invoice.TRANSMISSION_STATUS_FAILED,
+        ) and self.event.settings.invoice_regenerate_allowed
+
+    @property
+    def transmission_type_instance(self):
+        from pretix.base.invoicing.transmission import transmission_types
+        return transmission_types.get(identifier=self.transmission_type)[0]
+
+    def set_transmission_failed(self, provider, data):
+        self.transmission_status = Invoice.TRANSMISSION_STATUS_FAILED
+        self.transmission_date = now()
+        if not self.transmission_provider and provider:
+            self.transmission_provider = provider
+        self.save(update_fields=["transmission_status", "transmission_date", "transmission_provider"])
+        self.order.log_action(
+            "pretix.event.order.invoice.sending_failed",
+            data={
+                "full_invoice_no": self.full_invoice_no,
+                "transmission_provider": provider,
+                "transmission_type": self.transmission_type,
+                "data": data,
+            }
+        )
+
 
 class InvoiceLine(models.Model):
     """

src/pretix/base/models/items.py

@@ -1925,6 +1925,25 @@ class Question(LoggedModel):
             raise ValidationError(_("The maximum value must not be lower than the minimum value."))
         super().clean()
 
+    def clean_type_change(self, old_type, new_type):
+        if old_type == new_type:
+            return True
+        if not self.pk or not self.answers.exists():
+            return True
+        if new_type == self.TYPE_TEXT and old_type != self.TYPE_FILE:
+            # All types can be converted to text except file
+            return True
+        if new_type == self.TYPE_STRING and old_type not in (self.TYPE_TEXT, self.TYPE_FILE):
+            # All types can be converted to string except text or file
+            return True
+        if new_type == self.TYPE_CHOICE_MULTIPLE and old_type == self.TYPE_CHOICE:
+            # Single-choice can be converted to multiple choice without loss
+            return True
+        raise ValidationError(
+            _("The system already contains answers to this question that are not compatible with changing the "
+              "type of question without data loss. Consider hiding this question and creating a new one instead.")
+        )
+
 
 class QuestionOption(models.Model):
     question = models.ForeignKey('Question', related_name='options', on_delete=models.CASCADE)

src/pretix/base/models/log.py

@@ -40,9 +40,6 @@ from django.contrib.contenttypes.models import ContentType
 from django.db import connections, models
 from django.utils.functional import cached_property
 
-from pretix.base.logentrytype_registry import log_entry_types, make_link
-from pretix.base.signals import is_app_active, logentry_object_link
-
 
 class VisibleOnlyManager(models.Manager):
     def get_queryset(self):
@@ -91,6 +88,8 @@ class LogEntry(models.Model):
         indexes = [models.Index(fields=["datetime", "id"])]
 
     def display(self):
+        from pretix.base.logentrytype_registry import log_entry_types
+
         log_entry_type, meta = log_entry_types.get(action_type=self.action_type)
         if log_entry_type:
             return log_entry_type.display(self, self.parsed_data)
@@ -128,6 +127,11 @@ class LogEntry(models.Model):
 
     @cached_property
     def display_object(self):
+        from pretix.base.logentrytype_registry import (
+            log_entry_types, make_link,
+        )
+        from pretix.base.signals import is_app_active, logentry_object_link
+
         from . import (
             Discount, Event, Item, Order, Question, Quota, SubEvent, Voucher,
         )

src/pretix/base/models/orders.py

@@ -1821,7 +1821,7 @@ class OrderPayment(models.Model):
 
     def fail(self, info=None, user=None, auth=None, log_data=None, send_mail=True):
         """
-        Marks the order as failed and sets info to ``info``, but only if the order is in ``created`` or ``pending``
+        Marks the order as failed and sets info to ``info``, but only if the order is in ``created``, ``pending`` or ``canceled``
         state. This is equivalent to setting ``state`` to ``OrderPayment.PAYMENT_STATE_FAILED`` and logging a failure,
         but it adds strong database locking since we do not want to report a failure for an order that has just
         been marked as paid.
@@ -1829,7 +1829,11 @@ class OrderPayment(models.Model):
         """
         with transaction.atomic():
             locked_instance = OrderPayment.objects.select_for_update(of=OF_SELF).get(pk=self.pk)
-            if locked_instance.state not in (OrderPayment.PAYMENT_STATE_CREATED, OrderPayment.PAYMENT_STATE_PENDING):
+            if locked_instance.state in (
+                OrderPayment.PAYMENT_STATE_CONFIRMED,
+                OrderPayment.PAYMENT_STATE_FAILED,
+                OrderPayment.PAYMENT_STATE_REFUNDED
+            ):
                 # Race condition detected, this payment is already confirmed
                 logger.info('Failed payment {} but ignored due to likely race condition.'.format(
                     self.full_id,
@@ -1935,6 +1939,7 @@ class OrderPayment(models.Model):
                          ignore_date=False, lock=True, payment_refund_sum=0, allow_generate_invoice=True):
         from pretix.base.services.invoices import (
             generate_cancellation, generate_invoice, invoice_qualified,
+            invoice_transmission_separately, transmit_invoice,
         )
         from pretix.base.services.locking import LOCK_TRUST_WINDOW
 
@@ -1965,13 +1970,19 @@ class OrderPayment(models.Model):
                     trigger_pdf=not send_mail or not self.order.event.settings.invoice_email_attachment
                 )
 
+        transmit_invoice_task = invoice_transmission_separately(invoice)
+        transmit_invoice_mail = not transmit_invoice_task and self.order.event.settings.invoice_email_attachment and self.order.email
+
         if send_mail and self.order.sales_channel.identifier in self.order.event.settings.mail_sales_channel_placed_paid:
-            self._send_paid_mail(invoice, user, mail_text)
+            self._send_paid_mail(invoice if transmit_invoice_mail else None, user, mail_text)
             if self.order.event.settings.mail_send_order_paid_attendee:
                 for p in self.order.positions.all():
                     if p.addon_to_id is None and p.attendee_email and p.attendee_email != self.order.email:
                         self._send_paid_mail_attendee(p, user)
 
+        if invoice and not transmit_invoice_mail:
+            transmit_invoice.apply_async(args=(self.order.event_id, invoice.pk, False))
+
     def _send_paid_mail_attendee(self, position, user):
         from pretix.base.services.mail import SendMailException
 
@@ -2001,7 +2012,7 @@ class OrderPayment(models.Model):
                 self.order.send_mail(
                     email_subject, email_template, email_context,
                     'pretix.event.order.email.order_paid', user,
-                    invoices=[invoice] if invoice and self.order.event.settings.invoice_email_attachment else [],
+                    invoices=[invoice] if invoice else [],
                     attach_tickets=True,
                     attach_ical=self.order.event.settings.mail_attach_ical
                 )
@@ -2373,17 +2384,17 @@ class OrderFee(models.Model):
             self.fee_type, self.value
         )
 
-    def _calculate_tax(self, tax_rule=None):
+    def _calculate_tax(self, tax_rule=None, invoice_address=None):
         if tax_rule:
             self.tax_rule = tax_rule
 
         try:
-            ia = self.order.invoice_address
+            ia = invoice_address or self.order.invoice_address
         except InvoiceAddress.DoesNotExist:
             ia = None
 
-        if not self.tax_rule and self.fee_type == "payment" and self.order.event.settings.tax_rate_default:
-            self.tax_rule = self.order.event.settings.tax_rate_default
+        if not self.tax_rule and self.fee_type == "payment" and self.order.event.settings.tax_rule_payment == "default":
+            self.tax_rule = self.order.event.cached_default_tax_rule
 
         if self.tax_rule:
             tax = self.tax_rule.tax(self.value, base_price_is='gross', invoice_address=ia, force_fixed_gross_price=True)
@@ -3289,6 +3300,9 @@ class InvoiceAddress(models.Model):
         blank=True
     )
 
+    transmission_type = models.CharField(max_length=255, default="email")
+    transmission_info = models.JSONField(null=True, blank=True)
+
     objects = ScopedManager(organizer='order__event__organizer')
     profiles = ScopedManager(organizer='customer__organizer')
 
@@ -3310,6 +3324,24 @@ class InvoiceAddress(models.Model):
                     kwargs['update_fields'] = {'name_cached', 'name_parts'}.union(kwargs['update_fields'])
         super().save(**kwargs)
 
+    def clear(self, except_name=False):
+        self.is_business = False
+        if not except_name:
+            self.name_cached = ""
+            self.name_parts = {}
+        self.company = ""
+        self.street = ""
+        self.zipcode = ""
+        self.city = ""
+        self.country_old = ""
+        self.country = ""
+        self.state = ""
+        self.vat_id = ""
+        self.vat_id_validated = False
+        self.custom_field = None
+        self.internal_reference = ""
+        self.beneficiary = ""
+
     def describe(self):
         parts = [
             self.company,
@@ -3322,6 +3354,7 @@ class InvoiceAddress(models.Model):
             self.internal_reference,
             (_('Beneficiary') + ': ' + self.beneficiary) if self.beneficiary else '',
         ]
+        parts += [f'{k}: {v}' for k, v in self.describe_transmission()]
         return '\n'.join([str(p).strip() for p in parts if p and str(p).strip()])
 
     @property
@@ -3376,9 +3409,28 @@ class InvoiceAddress(models.Model):
             'custom_field': self.custom_field,
             'internal_reference': self.internal_reference,
             'beneficiary': self.beneficiary,
+            'transmission_type': self.transmission_type,
+            **(self.transmission_info or {}),
         })
         return d
 
+    def describe_transmission(self):
+        from pretix.base.invoicing.transmission import transmission_types
+        data = []
+
+        t, __ = transmission_types.get(identifier=self.transmission_type)
+        data.append((_("Transmission type"), t.public_name))
+        form_data = t.transmission_info_to_form_data(self.transmission_info or {})
+        for k, f in t.invoice_address_form_fields.items():
+            v = form_data.get(k)
+            if v is True:
+                v = _("Yes")
+            elif v is False:
+                v = _("No")
+            if v:
+                data.append((f.label, v))
+        return data
+
 
 def cachedticket_name(instance, filename: str) -> str:
     secret = get_random_string(length=16, allowed_chars=string.ascii_letters + string.digits)

src/pretix/base/models/organizer.py

@@ -68,6 +68,8 @@ class Organizer(LoggedModel):
     :param slug: A globally unique, short name for this organizer, to be used
                  in URLs and similar places.
     :type slug: str
+    :param plugins: A comma-separated list of plugin names that are active for this organizer.
+    :type plugins: str
     """
 
     settings_namespace = 'organizer'
@@ -91,6 +93,10 @@ class Organizer(LoggedModel):
         verbose_name=_("Short form"),
         unique=True
     )
+    plugins = models.TextField(
+        verbose_name=_("Plugins"),
+        null=False, blank=True, default="",
+    )
 
     class Meta:
         verbose_name = _("Organizer")
@@ -119,6 +125,11 @@ class Organizer(LoggedModel):
         """
         self.settings.cookie_consent = True
 
+        plugins = [p for p in settings.PRETIX_PLUGINS_ORGANIZER_DEFAULT.split(",") if p]
+        if plugins and not self.get_plugins():
+            self.set_active_plugins(plugins, allow_restricted=plugins)
+            self.save()
+
     def get_cache(self):
         """
         Returns an :py:class:`ObjectRelatedCache` object. This behaves equivalent to
@@ -143,6 +154,61 @@ class Organizer(LoggedModel):
 
         return ObjectRelatedCache(self)
 
+    def get_plugins(self):
+        """
+        Returns the names of the plugins activated for this organizer as a list.
+        """
+        if not self.plugins:
+            return []
+        return self.plugins.split(",")
+
+    def get_available_plugins(self):
+        from pretix.base.plugins import get_all_plugins
+
+        return {
+            p.module: p for p in get_all_plugins(organizer=self)
+            if not p.name.startswith('.') and getattr(p, 'visible', True)
+        }
+
+    def set_active_plugins(self, modules, allow_restricted=frozenset()):
+        plugins_active = self.get_plugins()
+        plugins_available = self.get_available_plugins()
+
+        enable = [m for m in modules if m not in plugins_active and m in plugins_available]
+
+        for module in enable:
+            if getattr(plugins_available[module].app, 'restricted', False) and module not in allow_restricted:
+                modules.remove(module)
+            elif hasattr(plugins_available[module].app, 'installed'):
+                getattr(plugins_available[module].app, 'installed')(self)
+
+        self.plugins = ",".join(modules)
+
+    def enable_plugin(self, module, allow_restricted=frozenset()):
+        """
+        Adds a plugin to the list of plugins, calling its ``installed`` hook (if available).
+        It is the caller's responsibility to save the organizer object.
+        """
+        plugins_active = self.get_plugins()
+        if module not in plugins_active:
+            plugins_active.append(module)
+            self.set_active_plugins(plugins_active, allow_restricted=allow_restricted)
+
+    def disable_plugin(self, module):
+        """
+        Removes a plugin from the list of plugins, calling its ``uninstalled`` hook (if available).
+        It is the caller's responsibility to save the organizer object and, in case of a hybrid organizer-event plugin,
+        to remove it from all events.
+        """
+        plugins_active = self.get_plugins()
+        if module in plugins_active:
+            plugins_active.remove(module)
+            self.set_active_plugins(plugins_active)
+
+            plugins_available = self.get_available_plugins()
+            if module in plugins_available and hasattr(plugins_available[module].app, 'uninstalled'):
+                getattr(plugins_available[module].app, 'uninstalled')(self)
+
     @property
     def timezone(self):
         return pytz_deprecation_shim.timezone(self.settings.timezone)

src/pretix/base/models/tax.py

@@ -377,9 +377,20 @@ class TaxRule(LoggedModel):
                     'if configured above.'),
     )
     custom_rules = models.TextField(blank=True, null=True)
+    default = models.BooleanField(
+        verbose_name=_('Default'),
+        default=False,
+    )
 
     class Meta:
         ordering = ('event', 'rate', 'id')
+        constraints = [
+            models.UniqueConstraint(
+                fields=["event"],
+                condition=models.Q(default=True),
+                name="one_default_per_event",
+            ),
+        ]
 
     class SaleNotAllowed(Exception):
         pass
@@ -394,7 +405,7 @@ class TaxRule(LoggedModel):
             and not OrderFee.objects.filter(tax_rule=self, order__event=self.event).exists()
             and not OrderPosition.all.filter(tax_rule=self, order__event=self.event).exists()
             and not self.event.items.filter(tax_rule=self).exists()
-            and self.event.settings.tax_rate_default != self
+            and not (self.default and self.event.tax_rules.filter(~models.Q(pk=self.pk)).exists())
         )
 
     @classmethod

src/pretix/base/models/vouchers.py

@@ -174,6 +174,9 @@ class Voucher(LoggedModel):
         ('percent', _('Reduce product price by (%)')),
     )
 
+    created = models.DateTimeField(
+        auto_now_add=True,
+    )
     event = models.ForeignKey(
         Event,
         on_delete=models.CASCADE,

src/pretix/base/models/waitinglist.py

@@ -207,16 +207,19 @@ class WaitingListEntry(LoggedModel):
                 block_quota=True,
                 subevent=self.subevent,
             )
-            v.log_action('pretix.voucher.added.waitinglist', {
+            v.log_action('pretix.voucher.added', {
                 'item': self.item.pk,
                 'variation': self.variation.pk if self.variation else None,
                 'tag': 'waiting-list',
                 'block_quota': True,
                 'valid_until': v.valid_until.isoformat(),
                 'max_usages': 1,
+                'subevent': self.subevent.pk if self.subevent else None,
+                'source': 'waitinglist',
+            }, user=user, auth=auth)
+            v.log_action('pretix.voucher.added.waitinglist', {
                 'email': self.email,
                 'waitinglistentry': self.pk,
-                'subevent': self.subevent.pk if self.subevent else None,
             }, user=user, auth=auth)
             self.voucher = v
             self.save()

src/pretix/base/pdf.py

@@ -48,6 +48,8 @@ from functools import partial
 from io import BytesIO
 
 import jsonschema
+import pypdf
+import pypdf.generic
 import reportlab.rl_config
 from bidi import get_display
 from django.conf import settings
@@ -159,8 +161,17 @@ DEFAULT_VARIABLES = OrderedDict((
         "editor_sample": _("123.45 EUR"),
         "evaluate": lambda op, order, event: money_filter(op.price, event.currency)
     }),
+    ("price_with_bundled", {
+        "label": _("Price including bundled products"),
+        "editor_sample": _("123.45 EUR"),
+        "evaluate": lambda op, order, event: money_filter(op.price + sum(
+            p.price
+            for p in op.addons.all()
+            if not p.canceled and p.is_bundled
+        ), event.currency)
+    }),
     ("price_with_addons", {
-        "label": _("Price including add-ons"),
+        "label": _("Price including add-ons and bundled products"),
         "editor_sample": _("123.45 EUR"),
         "evaluate": lambda op, order, event: money_filter(op.price + sum(
             p.price
@@ -808,7 +819,7 @@ class Renderer:
             # and does not deal with our default value here properly
             content = op.secret
         else:
-            content = self._get_text_content(op, order, o)
+            content = self._get_text_content(op, order, o).strip()
 
         if len(content) == 0:
             return
@@ -1178,8 +1189,7 @@ class Renderer:
 
             for i, page in enumerate(fg_pdf.pages):
                 bg_page = self.bg_pdf.pages[i]
-                if bg_page.rotation != 0:
-                    bg_page.transfer_rotation_to_content()
+                _correct_page_media_box(bg_page)
                 page.merge_page(bg_page, over=False)
                 output.add_page(page)
 
@@ -1248,8 +1258,7 @@ def merge_background(fg_pdf: PdfWriter, bg_pdf: PdfWriter, out_file, compress):
     else:
         for i, page in enumerate(fg_pdf.pages):
             bg_page = bg_pdf.pages[i]
-            if bg_page.rotation != 0:
-                bg_page.transfer_rotation_to_content()
+            _correct_page_media_box(bg_page)
             page.merge_page(bg_page, over=False)
 
         # pdf_header is a string like "%pdf-X.X"
@@ -1259,6 +1268,29 @@ def merge_background(fg_pdf: PdfWriter, bg_pdf: PdfWriter, out_file, compress):
         fg_pdf.write(out_file)
 
 
+def _correct_page_media_box(page: pypdf.PageObject):
+    if page.rotation != 0:
+        page.transfer_rotation_to_content()
+    media_box = page.mediabox
+    trsf = pypdf.Transformation()
+    if media_box.bottom != 0:
+        trsf = trsf.translate(0, -media_box.bottom)
+    if media_box.left != 0:
+        trsf = trsf.translate(-media_box.left, 0)
+    page.add_transformation(trsf, False)
+    for b in ["/MediaBox", "/CropBox", "/BleedBox", "/TrimBox", "/ArtBox"]:
+        if b in page:
+            rr = pypdf.generic.RectangleObject(page[b])
+            pt1 = trsf.apply_on(rr.lower_left)
+            pt2 = trsf.apply_on(rr.upper_right)
+            page[pypdf.generic.NameObject(b)] = pypdf.generic.RectangleObject((
+                min(pt1[0], pt2[0]),
+                min(pt1[1], pt2[1]),
+                max(pt1[0], pt2[0]),
+                max(pt1[1], pt2[1]),
+            ))
+
+
 @deconstructible
 class PdfLayoutValidator:
     def __call__(self, value):

src/pretix/base/plugins.py

@@ -28,8 +28,13 @@ import importlib_metadata as metadata
 from django.apps import AppConfig, apps
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
+from django.utils.translation import gettext_lazy as _
 from packaging.requirements import Requirement
 
+PLUGIN_LEVEL_EVENT = 'event'
+PLUGIN_LEVEL_ORGANIZER = 'organizer'
+PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID = 'event_organizer'
+
 
 class PluginType(Enum):
     """
@@ -43,11 +48,14 @@ class PluginType(Enum):
     EXPORT = 4
 
 
-def get_all_plugins(event=None) -> List[type]:
+def get_all_plugins(*, event=None, organizer=None) -> List[type]:
     """
     Returns the PretixPluginMeta classes of all plugins found in the installed Django apps.
     """
+    assert not event or not organizer
     plugins = []
+    event_fallback = None
+    event_fallback_used = False
     for app in apps.get_app_configs():
         if hasattr(app, 'PretixPluginMeta'):
             meta = app.PretixPluginMeta
@@ -56,8 +64,26 @@ def get_all_plugins(event=None) -> List[type]:
             if app.name in settings.PRETIX_PLUGINS_EXCLUDE:
                 continue
 
-            if hasattr(app, 'is_available') and event:
-                if not app.is_available(event):
+            level = getattr(app, "level", PLUGIN_LEVEL_EVENT)
+            if level == PLUGIN_LEVEL_EVENT:
+                if event and hasattr(app, 'is_available'):
+                    if not app.is_available(event):
+                        continue
+                elif organizer and hasattr(app, 'is_available'):
+                    if not event_fallback_used:
+                        event_fallback = organizer.events.first()
+                        event_fallback_used = True
+                    if not event_fallback or not app.is_available(event_fallback):
+                        continue
+            elif level == PLUGIN_LEVEL_ORGANIZER:
+                if organizer and hasattr(app, 'is_available'):
+                    if not app.is_available(organizer):
+                        continue
+                elif event and hasattr(app, 'is_available'):
+                    if not app.is_available(event.organizer):
+                        continue
+            elif level == PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID and (event or organizer) and hasattr(app, 'is_available'):
+                if not app.is_available(event or organizer):
                     continue
 
             plugins.append(meta)
@@ -91,3 +117,26 @@ class PluginConfig(AppConfig, metaclass=PluginConfigMeta):
                     self.name, req, requirement_version
                 ))
                 sys.exit(1)
+
+        if not hasattr(self.PretixPluginMeta, 'level'):
+            self.PretixPluginMeta.level = PLUGIN_LEVEL_EVENT
+        if self.PretixPluginMeta.level not in (PLUGIN_LEVEL_EVENT, PLUGIN_LEVEL_ORGANIZER, PLUGIN_LEVEL_EVENT_ORGANIZER_HYBRID):
+            raise ImproperlyConfigured(f"Unknown plugin level '{self.PretixPluginMeta.level}'")
+
+
+CATEGORY_ORDER = [
+    'FEATURE',
+    'PAYMENT',
+    'INTEGRATION',
+    'CUSTOMIZATION',
+    'FORMAT',
+    'API',
+]
+CATEGORY_LABELS = {
+    'FEATURE': _('Features'),
+    'PAYMENT': _('Payment providers'),
+    'INTEGRATION': _('Integrations'),
+    'CUSTOMIZATION': _('Customizations'),
+    'FORMAT': _('Output and export formats'),
+    'API': _('API features'),
+}

src/pretix/base/reldate.py

@@ -28,6 +28,9 @@ from dateutil import parser
 from django import forms
 from django.core.exceptions import ValidationError
 from django.db import models
+from django.utils.formats import get_format
+from django.utils.functional import lazy
+from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 from rest_framework import serializers
 
@@ -206,14 +209,27 @@ class RelativeDateTimeWidget(forms.MultiWidget):
     def __init__(self, *args, **kwargs):
         self.status_choices = kwargs.pop('status_choices')
         base_choices = kwargs.pop('base_choices')
+
+        def placeholder_datetime_format():
+            df = get_format('DATETIME_INPUT_FORMATS')[0]
+            return now().replace(
+                year=2000, month=12, day=31, hour=18, minute=0, second=0, microsecond=0
+            ).strftime(df)
+
+        def placeholder_time_format():
+            tf = get_format('TIME_INPUT_FORMATS')[0]
+            return datetime.time(8, 30, 0).strftime(tf)
+
         widgets = reldatetimeparts(
             status=forms.RadioSelect(choices=self.status_choices),
             absolute=forms.DateTimeInput(
-                attrs={'class': 'datetimepicker'}
+                attrs={'placeholder': lazy(placeholder_datetime_format, str), 'class': 'datetimepicker'}
             ),
             rel_days_number=forms.NumberInput(),
             rel_mins_relationto=forms.Select(choices=base_choices),
-            rel_days_timeofday=forms.TimeInput(attrs={'placeholder': _('Time'), 'class': 'timepickerfield'}),
+            rel_days_timeofday=forms.TimeInput(
+                attrs={'placeholder': lazy(placeholder_time_format, str), 'class': 'timepickerfield'}
+            ),
             rel_mins_number=forms.NumberInput(),
             rel_days_relationto=forms.Select(choices=base_choices),
             rel_mins_relation=forms.Select(choices=BEFORE_AFTER_CHOICE),

src/pretix/base/services/cancelevent.py

@@ -32,7 +32,7 @@ from pretix.base.email import get_email_context
 from pretix.base.i18n import language
 from pretix.base.models import (
     Event, InvoiceAddress, Order, OrderFee, OrderPosition, OrderRefund,
-    SubEvent, User, WaitingListEntry,
+    SubEvent, TaxRule, User, WaitingListEntry,
 )
 from pretix.base.services.locking import LockTimeoutException
 from pretix.base.services.mail import SendMailException, mail
@@ -40,6 +40,7 @@ from pretix.base.services.orders import (
     OrderChangeManager, OrderError, _cancel_order, _try_auto_refund,
 )
 from pretix.base.services.tasks import ProfiledEventTask
+from pretix.base.services.tax import split_fee_for_taxes
 from pretix.celery_app import app
 from pretix.helpers import OF_SELF
 from pretix.helpers.format import format_map
@@ -268,14 +269,34 @@ def cancel_event(self, event: Event, subevent: int, auto_refund: bool,
                 fee += Decimal(keep_fee_percentage) / Decimal('100.00') * total
             fee = round_decimal(min(fee, o.payment_refund_sum), event.currency)
             if fee:
-                f = OrderFee(
-                    fee_type=OrderFee.FEE_TYPE_CANCELLATION,
-                    value=fee,
-                    order=o,
-                    tax_rule=o.event.settings.tax_rate_default,
-                )
-                f._calculate_tax()
-                ocm.add_fee(f)
+                tax_rule_zero = TaxRule.zero()
+                if event.settings.tax_rule_cancellation == "default":
+                    fee_values = [(event.cached_default_tax_rule or tax_rule_zero, fee)]
+                elif event.settings.tax_rule_cancellation == "split":
+                    fee_values = split_fee_for_taxes(positions, fee, event)
+                else:
+                    fee_values = [(tax_rule_zero, fee)]
+
+                try:
+                    ia = o.invoice_address
+                except InvoiceAddress.DoesNotExist:
+                    ia = None
+
+                for tax_rule, price in fee_values:
+                    tax_rule = tax_rule or tax_rule_zero
+                    tax = tax_rule.tax(
+                        price, invoice_address=ia, base_price_is="gross"
+                    )
+                    f = OrderFee(
+                        fee_type=OrderFee.FEE_TYPE_CANCELLATION,
+                        value=price,
+                        order=o,
+                        tax_rate=tax.rate,
+                        tax_code=tax.code,
+                        tax_value=tax.tax,
+                        tax_rule=tax_rule,
+                    )
+                    ocm.add_fee(f)
 
             ocm.commit()
             refund_amount = o.payment_refund_sum - o.total

src/pretix/base/services/cart.py

@@ -1534,7 +1534,10 @@ def get_fees(event, request, total, invoice_address, payments, positions):
             total_remaining -= to_pay
 
             if payment_fee:
-                payment_fee_tax_rule = event.settings.tax_rate_default or TaxRule.zero()
+                if event.settings.tax_rule_payment == "default":
+                    payment_fee_tax_rule = event.cached_default_tax_rule or TaxRule.zero()
+                else:
+                    payment_fee_tax_rule = TaxRule.zero()
                 payment_fee_tax = payment_fee_tax_rule.tax(payment_fee, base_price_is='gross', invoice_address=invoice_address)
                 fees.append(OrderFee(
                     fee_type=OrderFee.FEE_TYPE_PAYMENT,

src/pretix/base/services/datasync.py

@@ -0,0 +1,105 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+import logging
+from datetime import timedelta
+from itertools import groupby
+
+from django.db.models import F, Window
+from django.db.models.functions import RowNumber
+from django.dispatch import receiver
+from django.utils.timezone import now
+from django_scopes import scope, scopes_disabled
+
+from pretix.base.datasync.datasync import datasync_providers
+from pretix.base.models.datasync import OrderSyncQueue
+from pretix.base.signals import periodic_task
+from pretix.celery_app import app
+
+logger = logging.getLogger(__name__)
+
+
+@receiver(periodic_task, dispatch_uid="data_sync_periodic_sync_all")
+def periodic_sync_all(sender, **kwargs):
+    sync_all.apply_async()
+
+
+@receiver(periodic_task, dispatch_uid="data_sync_periodic_reset_in_flight")
+def periodic_reset_in_flight(sender, **kwargs):
+    for sq in OrderSyncQueue.objects.filter(
+        in_flight=True,
+        in_flight_since__lt=now() - timedelta(minutes=20),
+    ):
+        sq.set_sync_error('timeout', [], 'Timeout')
+
+
+def run_sync(queue):
+    grouped = groupby(sorted(queue, key=lambda q: (q.sync_provider, q.event.pk)), lambda q: (q.sync_provider, q.event))
+    for (target, event), queued_orders in grouped:
+        target_cls, meta = datasync_providers.get(identifier=target, active_in=event)
+
+        if not target_cls:
+            # sync plugin not found (plugin deactivated or uninstalled) -> drop outstanding jobs
+            num_deleted, _ = OrderSyncQueue.objects.filter(pk__in=[sq.pk for sq in queued_orders]).delete()
+            logger.info("Deleted %d queue entries from %r because plugin %s inactive", num_deleted, event, target)
+            continue
+
+        with scope(organizer=event.organizer):
+            with target_cls(event=event) as p:
+                p.sync_queued_orders(queued_orders)
+
+
+@app.task()
+def sync_all():
+    with scopes_disabled():
+        queue = (
+            OrderSyncQueue.objects
+            .filter(
+                in_flight=False,
+                not_before__lt=now(),
+                need_manual_retry__isnull=True,
+            )
+            .order_by(Window(
+                expression=RowNumber(),
+                partition_by=[F("event_id")],
+                order_by="not_before",
+            ))
+            .prefetch_related("event")
+            [:1000]
+        )
+        run_sync(queue)
+
+
+@app.task()
+def sync_single(queue_item_id: int):
+    with scopes_disabled():
+        queue = (
+            OrderSyncQueue.objects
+            .filter(
+                pk=queue_item_id,
+                in_flight=False,
+                not_before__lt=now(),
+                need_manual_retry__isnull=True,
+            )
+            .prefetch_related("event")
+        )
+        run_sync(queue)

src/pretix/base/services/invoices.py

@@ -51,11 +51,16 @@ from django_scopes import scope, scopes_disabled
 from i18nfield.strings import LazyI18nString
 
 from pretix.base.i18n import language
+from pretix.base.invoicing.transmission import (
+    get_transmission_types, transmission_providers,
+)
 from pretix.base.models import (
     ExchangeRate, Invoice, InvoiceAddress, InvoiceLine, Order, OrderFee,
 )
 from pretix.base.models.tax import EU_CURRENCIES
-from pretix.base.services.tasks import TransactionAwareTask
+from pretix.base.services.tasks import (
+    TransactionAwareProfiledEventTask, TransactionAwareTask,
+)
 from pretix.base.signals import invoice_line_text, periodic_task
 from pretix.celery_app import app
 from pretix.helpers.database import OF_SELF, rolledback_transaction
@@ -71,12 +76,13 @@ def _location_oneliner(loc):
 @transaction.atomic
 def build_invoice(invoice: Invoice) -> Invoice:
     invoice.locale = invoice.event.settings.get('invoice_language', invoice.event.settings.locale)
+    invoice.transmission_status = Invoice.TRANSMISSION_STATUS_PENDING
     if invoice.locale == '__user__':
         invoice.locale = invoice.order.locale or invoice.event.settings.locale
 
     lp = invoice.order.payments.last()
 
-    with language(invoice.locale, invoice.event.settings.region):
+    with (language(invoice.locale, invoice.event.settings.region)):
         invoice.invoice_from = invoice.event.settings.get('invoice_address_from')
         invoice.invoice_from_name = invoice.event.settings.get('invoice_address_from_name')
         invoice.invoice_from_zipcode = invoice.event.settings.get('invoice_address_from_zipcode')
@@ -127,6 +133,7 @@ def build_invoice(invoice: Invoice) -> Invoice:
             invoice.internal_reference = ia.internal_reference
             invoice.custom_field = ia.custom_field
             invoice.invoice_to_company = ia.company
+            invoice.invoice_to_is_business = ia.is_business
             invoice.invoice_to_name = ia.name
             invoice.invoice_to_street = ia.street
             invoice.invoice_to_zipcode = ia.zipcode
@@ -134,6 +141,8 @@ def build_invoice(invoice: Invoice) -> Invoice:
             invoice.invoice_to_country = ia.country
             invoice.invoice_to_state = ia.state
             invoice.invoice_to_beneficiary = ia.beneficiary
+            invoice.invoice_to_transmission_info = ia.transmission_info or {}
+            invoice.transmission_type = ia.transmission_type
 
             if ia.vat_id:
                 invoice.invoice_to += "\n" + pgettext("invoice", "VAT-ID: %s") % ia.vat_id
@@ -356,7 +365,9 @@ def generate_cancellation(invoice: Invoice, trigger_pdf=True):
     cancellation.payment_provider_stamp = ''
     cancellation.file = None
     cancellation.sent_to_organizer = None
-    cancellation.sent_to_customer = None
+    cancellation.transmission_provider = None
+    cancellation.transmission_status = Invoice.TRANSMISSION_STATUS_PENDING
+    cancellation.transmission_date = None
     with language(invoice.locale, invoice.event.settings.region):
         cancellation.invoice_from = invoice.event.settings.get('invoice_address_from')
         cancellation.invoice_from_name = invoice.event.settings.get('invoice_address_from_name')
@@ -512,6 +523,36 @@ def build_preview_invoice_pdf(event):
         return event.invoice_renderer.generate(invoice)
 
 
+def order_invoice_transmission_separately(order):
+    try:
+        info = order.invoice_address.transmission_info or {}
+        return (
+            order.invoice_address.transmission_type != "email" or
+            (
+                info.get("transmission_email_address") and
+                order.email != info["transmission_email_address"]
+            )
+        )
+    except InvoiceAddress.DoesNotExist:
+        return False
+
+
+def invoice_transmission_separately(invoice):
+    if not invoice:
+        return False
+    try:
+        info = invoice.invoice_to_transmission_info or {}
+        return (
+            invoice.transmission_type != "email" or
+            (
+                info.get("transmission_email_address") and
+                invoice.order.email != info["transmission_email_address"]
+            )
+        )
+    except InvoiceAddress.DoesNotExist:
+        return False
+
+
 @receiver(signal=periodic_task)
 @scopes_disabled()
 def send_invoices_to_organizer(sender, **kwargs):
@@ -551,3 +592,100 @@ def send_invoices_to_organizer(sender, **kwargs):
                 else:
                     i.sent_to_organizer = False
                 i.save(update_fields=['sent_to_organizer'])
+
+
+@receiver(signal=periodic_task)
+@scopes_disabled()
+def retry_stuck_invoices(sender, **kwargs):
+    with transaction.atomic():
+        qs = Invoice.objects.filter(
+            transmission_status=Invoice.TRANSMISSION_STATUS_INFLIGHT,
+            transmission_date__lte=now() - timedelta(hours=24),
+        ).select_for_update(
+            of=OF_SELF, skip_locked=connection.features.has_select_for_update_skip_locked
+        )
+        batch_size = 5000
+        for invoice in qs[:batch_size]:
+            invoice.transmission_status = Invoice.TRANSMISSION_STATUS_PENDING
+            invoice.transmission_date = now()
+            invoice.save(update_fields=["transmission_status", "transmission_date"])
+            transmit_invoice.apply_async(args=(invoice.event_id, invoice.pk, True))
+
+
+@receiver(signal=periodic_task)
+@scopes_disabled()
+def send_pending_invoices(sender, **kwargs):
+    with transaction.atomic():
+        # Transmit all invoices that have not been transmitted by another process if the provider enforces
+        # transmission
+        types = [
+            tt.identifier for tt in get_transmission_types()
+            if tt.enforce_transmission
+        ]
+        qs = Invoice.objects.filter(
+            transmission_type__in=types,
+            transmission_status=Invoice.TRANSMISSION_STATUS_PENDING,
+            created__lte=now() - timedelta(minutes=15),
+        ).select_for_update(
+            of=OF_SELF, skip_locked=connection.features.has_select_for_update_skip_locked
+        )
+        batch_size = 5000
+        for invoice in qs[:batch_size]:
+            transmit_invoice.apply_async(args=(invoice.event_id, invoice.pk, False))
+
+
+@app.task(base=TransactionAwareProfiledEventTask)
+def transmit_invoice(sender, invoice_id, allow_retransmission=True, **kwargs):
+    with transaction.atomic(durable='tests.testdummy' not in settings.INSTALLED_APPS):
+        # We need durable=True for transactional correctness, but can't have it during tests
+        invoice = Invoice.objects.select_for_update(of=OF_SELF).get(pk=invoice_id)
+
+        if invoice.transmission_status == Invoice.TRANSMISSION_STATUS_INFLIGHT:
+            logger.info(f"Did not transmit invoice {invoice.pk} due to being in inflight state.")
+            return
+
+        if invoice.transmission_status != Invoice.TRANSMISSION_STATUS_PENDING and not allow_retransmission:
+            logger.info(f"Did not transmit invoice {invoice.pk} due to status being {invoice.transmission_status}.")
+            return
+
+        invoice.transmission_status = Invoice.TRANSMISSION_STATUS_INFLIGHT
+        invoice.transmission_date = now()
+        invoice.save(update_fields=["transmission_status", "transmission_date"])
+
+    providers = sorted([
+        provider
+        for provider, __ in transmission_providers.filter(type=invoice.transmission_type, active_in=sender)
+    ], key=lambda p: (-p.priority, p.identifier))
+
+    provider = None
+    for p in providers:
+        if p.is_available(sender, invoice.invoice_to_country, invoice.invoice_to_is_business):
+            provider = p
+            break
+
+    if not provider:
+        invoice.set_transmission_failed(provider=None, data={"reason": "no_provider"})
+        return
+
+    if invoice.order.testmode and not provider.testmode_supported:
+        invoice.transmission_status = Invoice.TRANSMISSION_STATUS_TESTMODE_IGNORED
+        invoice.transmission_date = now()
+        invoice.save(update_fields=["transmission_status", "transmission_date"])
+        invoice.order.log_action(
+            "pretix.event.order.invoice.testmode_ignored",
+            data={
+                "full_invoice_no": invoice.full_invoice_no,
+                "transmission_provider": None,
+                "transmission_type": invoice.transmission_type,
+            }
+        )
+        return
+
+    try:
+        provider.transmit(invoice)
+    except Exception as e:
+        logger.exception(f"Transmission of invoice {invoice.pk} failed with exception.")
+        invoice.set_transmission_failed(provider=provider.identifier, data={
+            "reason": "exception",
+            "exception": str(e),
+        })

src/pretix/base/services/mail.py

@@ -222,7 +222,7 @@ def mail(email: Union[str, Sequence[str]], subject: str, template: Union[str, La
                     'invoice_company': ''
                 })
         renderer = ClassicMailRenderer(None, organizer)
-        content_plain = body_plain = render_mail(template, context)
+        body_plain = render_mail(template, context, placeholder_mode=SafeFormatter.MODE_RICH_TO_PLAIN)
         subject = str(subject).format_map(TolerantDict(context))
         sender = (
             sender or
@@ -316,6 +316,7 @@ def mail(email: Union[str, Sequence[str]], subject: str, template: Union[str, La
 
         with override(timezone):
             try:
+                content_plain = render_mail(template, context, placeholder_mode=None)
                 if plain_text_only:
                     body_html = None
                 elif 'context' in inspect.signature(renderer.render).parameters:
@@ -405,8 +406,12 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
         attach_cid_images(html_message, cid_images, verify_ssl=True)
         email.attach_alternative(html_message, "multipart/related")
 
+    log_target = None
+
     if user:
         user = User.objects.get(pk=user)
+        error_log_action_type = 'pretix.user.email.error'
+        log_target = user
 
     if event:
         with scopes_disabled():
@@ -426,12 +431,15 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
     with cm():
         if customer:
             customer = Customer.objects.get(pk=customer)
-        log_target = user or customer
+            if not user:
+                error_log_action_type = 'pretix.customer.email.error'
+                log_target = customer
 
         if event:
             if order:
                 try:
                     order = event.orders.get(pk=order)
+                    error_log_action_type = 'pretix.event.order.email.error'
                     log_target = order
                 except Order.DoesNotExist:
                     order = None
@@ -488,7 +496,7 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
 
             email = email_filter.send_chained(event, 'message', message=email, order=order, user=user)
 
-        invoices_sent = []
+        invoices_to_mark_transmitted = []
         if invoices:
             invoices = Invoice.objects.filter(pk__in=invoices)
             for inv in invoices:
@@ -509,7 +517,23 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                                 inv.file.file.read(),
                                 'application/pdf'
                             )
-                        invoices_sent.append(inv)
+
+                        if inv.transmission_type == "email":
+                            # Mark invoice as sent when it was sent to the requested address *either* at the time of
+                            # invoice creation *or* as of right now.
+                            expected_recipients = [
+                                (inv.invoice_to_transmission_info or {}).get("transmission_email_address")
+                                or inv.order.email,
+                            ]
+                            try:
+                                expected_recipients.append(
+                                    (inv.order.invoice_address.transmission_info or {}).get("transmission_email_address")
+                                    or inv.order.email
+                                )
+                            except InvoiceAddress.DoesNotExist:
+                                pass
+                            if any(t in expected_recipients for t in to):
+                                invoices_to_mark_transmitted.append(inv)
                     except:
                         logger.exception('Could not attach invoice to email')
                         pass
@@ -574,7 +598,7 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                 except MaxRetriesExceededError:
                     if log_target:
                         log_target.log_action(
-                            'pretix.email.error',
+                            error_log_action_type,
                             data={
                                 'subject': 'SMTP code {}, max retries exceeded'.format(e.smtp_code),
                                 'message': e.smtp_error.decode() if isinstance(e.smtp_error, bytes) else str(e.smtp_error),
@@ -582,12 +606,17 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                                 'invoices': [],
                             }
                         )
+                    for i in invoices_to_mark_transmitted:
+                        i.set_transmission_failed(provider="email_pdf", data={
+                            "reason": "exception",
+                            "exception": "SMTP code {}, max retries exceeded".format(e.smtp_code),
+                        })
                     raise e
 
             logger.exception('Error sending email')
             if log_target:
                 log_target.log_action(
-                    'pretix.email.error',
+                    error_log_action_type,
                     data={
                         'subject': 'SMTP code {}'.format(e.smtp_code),
                         'message': e.smtp_error.decode() if isinstance(e.smtp_error, bytes) else str(e.smtp_error),
@@ -595,6 +624,11 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                         'invoices': [],
                     }
                 )
+            for i in invoices_to_mark_transmitted:
+                i.set_transmission_failed(provider="email_pdf", data={
+                    "reason": "exception",
+                    "exception": "SMTP code {}".format(e.smtp_code),
+                })
 
             raise SendMailException('Failed to send an email to {}.'.format(to))
         except smtplib.SMTPRecipientsRefused as e:
@@ -618,7 +652,7 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                     message.append(f'{e}: {val[0]} {val[1].decode()}')
 
                 log_target.log_action(
-                    'pretix.email.error',
+                    error_log_action_type,
                     data={
                         'subject': 'SMTP error',
                         'message': '\n'.join(message),
@@ -626,6 +660,11 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                         'invoices': [],
                     }
                 )
+            for i in invoices_to_mark_transmitted:
+                i.set_transmission_failed(provider="email_pdf", data={
+                    "reason": "exception",
+                    "exception": "SMTP error",
+                })
 
             raise SendMailException('Failed to send an email to {}.'.format(to))
         except Exception as e:
@@ -635,7 +674,7 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                 except MaxRetriesExceededError:
                     if log_target:
                         log_target.log_action(
-                            'pretix.email.error',
+                            error_log_action_type,
                             data={
                                 'subject': 'Internal error',
                                 'message': f'Max retries exceeded after error "{str(e)}"',
@@ -643,10 +682,15 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                                 'invoices': [],
                             }
                         )
+                    for i in invoices_to_mark_transmitted:
+                        i.set_transmission_failed(provider="email_pdf", data={
+                            "reason": "exception",
+                            "exception": "Internal error",
+                        })
                     raise e
             if log_target:
                 log_target.log_action(
-                    'pretix.email.error',
+                    error_log_action_type,
                     data={
                         'subject': 'Internal error',
                         'message': str(e),
@@ -654,23 +698,63 @@ def mail_send_task(self, *args, to: List[str], subject: str, body: str, html: st
                         'invoices': [],
                     }
                 )
+            for i in invoices_to_mark_transmitted:
+                i.set_transmission_failed(provider="email_pdf", data={
+                    "reason": "exception",
+                    "exception": "Internal error",
+                })
             logger.exception('Error sending email')
             raise SendMailException('Failed to send an email to {}.'.format(to))
         else:
-            for i in invoices_sent:
-                i.sent_to_customer = now()
-                i.save(update_fields=['sent_to_customer'])
+            for i in invoices_to_mark_transmitted:
+                if i.transmission_status != Invoice.TRANSMISSION_STATUS_COMPLETED:
+                    i.transmission_date = now()
+                    i.transmission_status = Invoice.TRANSMISSION_STATUS_COMPLETED
+                    i.transmission_provider = "email_pdf"
+                    i.transmission_info = {
+                        "sent": [
+                            {
+                                "recipients": to,
+                                "datetime": now().isoformat(),
+                            }
+                        ]
+                    }
+                    i.save(update_fields=[
+                        "transmission_date", "transmission_provider", "transmission_status",
+                        "transmission_info"
+                    ])
+                elif i.transmission_provider == "email_pdf":
+                    i.transmission_info["sent"].append(
+                        {
+                            "recipients": to,
+                            "datetime": now().isoformat(),
+                        }
+                    )
+                    i.save(update_fields=[
+                        "transmission_info"
+                    ])
+                i.order.log_action(
+                    "pretix.event.order.invoice.sent",
+                    data={
+                        "full_invoice_no": i.full_invoice_no,
+                        "transmission_provider": "email_pdf",
+                        "transmission_type": "email",
+                        "data": {
+                            "recipients": [to],
+                        },
+                    }
+                )
 
 
 def mail_send(*args, **kwargs):
     mail_send_task.apply_async(args=args, kwargs=kwargs)
 
 
-def render_mail(template, context):
+def render_mail(template, context, placeholder_mode=SafeFormatter.MODE_RICH_TO_PLAIN):
     if isinstance(template, LazyI18nString):
         body = str(template)
-        if context:
-            body = format_map(body, context, mode=SafeFormatter.MODE_IGNORE_RICH)
+        if context and placeholder_mode:
+            body = format_map(body, context, mode=placeholder_mode)
     else:
         tpl = get_template(template)
         body = tpl.render(context)

src/pretix/base/services/modelimport.py

@@ -89,6 +89,9 @@ def import_orders(event: Event, fileid: str, settings: dict, locale: str, user,
                 _('Orders cannot have more than %(max)s positions.') % {'max': django_settings.PRETIX_MAX_ORDER_SIZE}
             )
 
+        used_groupers = set()
+        current_grouper = []
+        current_order_level_data = {}
         orders = []
         order = None
 
@@ -97,7 +100,28 @@ def import_orders(event: Event, fileid: str, settings: dict, locale: str, user,
         lock_seats = []
         for i, record in enumerate(data):
             try:
-                if order is None or settings['orders'] == 'many':
+                create_new_order = (
+                    order is None or
+                    settings['orders'] == 'many' or
+                    (settings['orders'] == 'mixed' and record["grouping"] != current_grouper)
+                )
+
+                if create_new_order:
+                    if settings['orders'] == 'mixed':
+                        if record["grouping"] in used_groupers:
+                            raise DataImportError(
+                                _('The grouping "%(value)s" occurs on non-consecutive lines (seen again on line %(row)s).') % {
+                                    "value": record["grouping"],
+                                    "row": i + 1,
+                                }
+                            )
+                        current_grouper = record["grouping"]
+                        used_groupers.add(current_grouper)
+
+                    current_order_level_data = {
+                        c.identifier: record.get(c.identifier)
+                        for c in cols if getattr(c, "order_level", False)
+                    }
                     order = Order(
                         event=event,
                         testmode=settings['testmode'],
@@ -108,6 +132,12 @@ def import_orders(event: Event, fileid: str, settings: dict, locale: str, user,
                     order._address.name_parts = {'_scheme': event.settings.name_scheme}
                     orders.append(order)
 
+                if settings['orders'] == 'mixed' and len(order._positions) >= django_settings.PRETIX_MAX_ORDER_SIZE:
+                    raise DataImportError(
+                        _('Orders cannot have more than %(max)s positions.') % {
+                            'max': django_settings.PRETIX_MAX_ORDER_SIZE}
+                    )
+
                 position = OrderPosition(positionid=len(order._positions) + 1)
                 position.attendee_name_parts = {'_scheme': event.settings.name_scheme}
                 position.meta_info = {}
@@ -115,13 +145,24 @@ def import_orders(event: Event, fileid: str, settings: dict, locale: str, user,
                 position.assign_pseudonymization_id()
 
                 for c in cols:
-                    c.assign(record.get(c.identifier), order, position, order._address)
+                    value = record.get(c.identifier)
+                    if getattr(c, "order_level", False) and value != current_order_level_data.get(c.identifier):
+                        raise DataImportError(
+                            _('Inconsistent data in row {row}: Column {col} contains value "{val_line}", but '
+                              'for this order, the value has already been set to "{val_order}".').format(
+                                row=i + 1,
+                                col=c.verbose_name,
+                                val_line=value,
+                                val_order=current_order_level_data.get(c.identifier) or "",
+                            )
+                        )
+                    c.assign(value, order, position, order._address)
 
                 if position.seat is not None:
                     lock_seats.append((order.sales_channel, position.seat))
             except (ValidationError, ImportError) as e:
                 raise DataImportError(
-                    _('Invalid data in row {row}: {message}').format(row=i, message=str(e))
+                    _('Invalid data in row {row}: {message}').format(row=i + 1, message=str(e))
                 )
 
         try: