Allow to disable display of foreign currencies on invoices

src/pretix/base/services/invoices.py

@@ -105,7 +105,7 @@ def build_invoice(invoice: Invoice) -> Invoice:
 
             cc = str(ia.country)
 
-            if cc in EU_CURRENCIES and EU_CURRENCIES[cc] != invoice.event.currency:
+            if cc in EU_CURRENCIES and EU_CURRENCIES[cc] != invoice.event.currency and invoice.event.settings.invoice_eu_currencies:
                 invoice.foreign_currency_display = EU_CURRENCIES[cc]
 
                 if settings.FETCH_ECB_RATES:

src/pretix/base/settings.py

@@ -198,6 +198,16 @@ DEFAULTS = {
             label=_("Show attendee names on invoices"),
         )
     },
+    'invoice_eu_currencies': {
+        'default': 'True',
+        'type': bool,
+        'form_class': forms.BooleanField,
+        'serializer_class': serializers.BooleanField,
+        'form_kwargs': dict(
+            label=_("On invoices from one EU country into another EU country with a different currency, print the "
+                    "tax amounts in both currencies if possible"),
+        )
+    },
     'invoice_address_required': {
         'default': 'False',
         'form_class': forms.BooleanField,