diff --git a/src/pretix/base/services/cart.py b/src/pretix/base/services/cart.py
index 04fbb7e6ac..1c39168a2f 100644
--- a/src/pretix/base/services/cart.py
+++ b/src/pretix/base/services/cart.py
@@ -195,7 +195,7 @@ class CartManager:
     AddOperation = namedtuple('AddOperation', ('count', 'item', 'variation', 'voucher', 'quotas',
                                                'addon_to', 'subevent', 'bundled', 'seat', 'listed_price',
                                                'price_after_voucher', 'custom_price_input',
-                                               'custom_price_input_is_net'))
+                                               'custom_price_input_is_net', 'voucher_ignored'))
     RemoveOperation = namedtuple('RemoveOperation', ('position',))
     VoucherOperation = namedtuple('VoucherOperation', ('position', 'voucher', 'price_after_voucher'))
     ExtendOperation = namedtuple('ExtendOperation', ('position', 'count', 'item', 'variation', 'voucher',
@@ -330,12 +330,16 @@ class CartManager:
                 (isinstance(op, self.ExtendOperation) and op.position.is_bundled)
             ):
                 if op.item.require_voucher and op.voucher is None:
+                    if getattr(op, 'voucher_ignored', False):
+                        raise CartError(error_messages['voucher_redeemed'])
                     raise CartError(error_messages['voucher_required'])
 
                 if (
                     (op.item.hide_without_voucher or (op.variation and op.variation.hide_without_voucher)) and
                     (op.voucher is None or not op.voucher.show_hidden_items)
                 ):
+                    if getattr(op, 'voucher_ignored', False):
+                        raise CartError(error_messages['voucher_redeemed'])
                     raise CartError(error_messages['voucher_required'])
 
             if not op.item.is_available() or (op.variation and not op.variation.is_available()):
@@ -480,7 +484,7 @@ class CartManager:
             self._check_item_constraints(op)
 
             if cp.voucher:
-                self._voucher_use_diff[cp.voucher] += 1
+                self._voucher_use_diff[cp.voucher] += 2
 
             self._operations.append(op)
         return err
@@ -586,6 +590,7 @@ class CartManager:
             item = self._items_cache[i['item']]
             variation = self._variations_cache[i['variation']] if i['variation'] is not None else None
             voucher = None
+            voucher_ignored = False
 
             if i.get('voucher'):
                 try:
@@ -595,6 +600,24 @@ class CartManager:
                 else:
                     voucher_use_diff[voucher] += i['count']
 
+                    if i.get('voucher_ignore_if_redeemed', False):
+                        # This is a special case handling for when a user clicks "+" on an existing line in their cart
+                        # that has a voucher attached. If the voucher still has redemptions left, we'll add another line
+                        # with the same voucher, but if it does not we silently continue as if there was no voucher,
+                        # leading to either a higher-priced ticket or an error. Still, this leads to less error cases
+                        # than either of the possible default assumptions.
+                        predicted_redeemed_after = (
+                            voucher.redeemed +
+                            CartPosition.objects.filter(voucher=voucher, expires__gte=self.now_dt).count() +
+                            self._voucher_use_diff[voucher] +
+                            voucher_use_diff[voucher]
+                        )
+                        if predicted_redeemed_after > voucher.max_usages:
+                            i.pop('voucher')
+                            voucher_ignored = True
+                            voucher = None
+                            voucher_use_diff[voucher] -= i['count']
+
             # Fetch all quotas. If there are no quotas, this item is not allowed to be sold.
             quotas = list(item.quotas.filter(subevent=subevent)
                           if variation is None else variation.quotas.filter(subevent=subevent))
@@ -641,6 +664,7 @@ class CartManager:
                     price_after_voucher=bundle.designated_price,
                     custom_price_input=None,
                     custom_price_input_is_net=False,
+                    voucher_ignored=False,
                 )
                 self._check_item_constraints(bop, operations)
                 bundled.append(bop)
@@ -670,6 +694,7 @@ class CartManager:
                 price_after_voucher=price_after_voucher,
                 custom_price_input=custom_price,
                 custom_price_input_is_net=self.event.settings.display_net_prices,
+                voucher_ignored=voucher_ignored,
             )
             self._check_item_constraints(op, operations)
             operations.append(op)
@@ -801,6 +826,7 @@ class CartManager:
                     price_after_voucher=listed_price,
                     custom_price_input=custom_price,
                     custom_price_input_is_net=self.event.settings.display_net_prices,
+                    voucher_ignored=False,
                 )
                 self._check_item_constraints(op, operations)
                 operations.append(op)
diff --git a/src/pretix/presale/templates/pretixpresale/event/fragment_cart.html b/src/pretix/presale/templates/pretixpresale/event/fragment_cart.html
index 8bff4b518a..b8fbce1788 100644
--- a/src/pretix/presale/templates/pretixpresale/event/fragment_cart.html
+++ b/src/pretix/presale/templates/pretixpresale/event/fragment_cart.html
@@ -267,6 +267,10 @@
                             data-asynctask-text="{% blocktrans with time=event.settings.reservation_time %}Once the items are in your cart, you will have {{ time }} minutes to complete your purchase.{% endblocktrans %}"
                         method="post" data-asynctask>
                         <input type="hidden" name="subevent" value="{{ line.subevent_id|default_if_none:"" }}" />
+                        {% if line.voucher and not line.voucher.seat %}
+                            <input type="hidden" name="_voucher_code" value="{{ line.voucher.code }}" />
+                            <input type="hidden" name="_voucher_ignore_if_redeemed" value="on" />
+                        {% endif %}
                         {% csrf_token %}
                         {% if line.variation %}
                             <input type="hidden" name="variation_{{ line.item.id }}_{{ line.variation.id }}"
diff --git a/src/pretix/presale/views/cart.py b/src/pretix/presale/views/cart.py
index 9b67804e8d..6b258f0a70 100644
--- a/src/pretix/presale/views/cart.py
+++ b/src/pretix/presale/views/cart.py
@@ -136,7 +136,7 @@ class CartActionMixin:
         except InvoiceAddress.DoesNotExist:
             return InvoiceAddress()
 
-    def _item_from_post_value(self, key, value, voucher=None):
+    def _item_from_post_value(self, key, value, voucher=None, voucher_ignore_if_redeemed=False):
         if value.strip() == '' or '_' not in key:
             return
 
@@ -161,6 +161,7 @@ class CartActionMixin:
                     'seat': value,
                     'price': price,
                     'voucher': voucher,
+                    'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
                     'subevent': subevent
                 }
             except ValueError:
@@ -183,6 +184,7 @@ class CartActionMixin:
                     'count': amount,
                     'price': price,
                     'voucher': voucher,
+                    'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
                     'subevent': subevent
                 }
             except ValueError:
@@ -195,6 +197,7 @@ class CartActionMixin:
                     'count': amount,
                     'price': price,
                     'voucher': voucher,
+                    'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
                     'subevent': subevent
                 }
             except ValueError:
@@ -219,7 +222,8 @@ class CartActionMixin:
         for key, values in req_items:
             for value in values:
                 try:
-                    item = self._item_from_post_value(key, value, self.request.POST.get('_voucher_code'))
+                    item = self._item_from_post_value(key, value, self.request.POST.get('_voucher_code'),
+                                                      voucher_ignore_if_redeemed=self.request.POST.get('_voucher_ignore_if_redeemed') == 'on')
                 except CartError as e:
                     messages.error(self.request, str(e))
                     return
diff --git a/src/tests/presale/test_cart.py b/src/tests/presale/test_cart.py
index 16f278b85c..827c8dfe63 100644
--- a/src/tests/presale/test_cart.py
+++ b/src/tests/presale/test_cart.py
@@ -327,6 +327,31 @@ class CartTest(CartTestMixin, TestCase):
             objs = list(CartPosition.objects.filter(cart_id=self.session_key, event=self.event))
         self.assertEqual(len(objs), 0)
 
+    def test_voucher_ignore_if_Redeemed(self):
+        with scopes_disabled():
+            v = Voucher.objects.create(item=self.ticket, event=self.event, max_usages=2)
+        self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '1',
+            '_voucher_code': v.code,
+            '_voucher_ignore_if_redeemed': 'on',
+        }, follow=True)
+        self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '1',
+            '_voucher_code': v.code,
+            '_voucher_ignore_if_redeemed': 'on',
+        }, follow=True)
+        self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '1',
+            '_voucher_code': v.code,
+            '_voucher_ignore_if_redeemed': 'on',
+        }, follow=True)
+        with scopes_disabled():
+            objs = list(CartPosition.objects.filter(cart_id=self.session_key, event=self.event).order_by('id'))
+        self.assertEqual(len(objs), 3)
+        self.assertEqual(objs[0].voucher, v)
+        self.assertEqual(objs[1].voucher, v)
+        self.assertIsNone(objs[2].voucher)
+
     def test_voucher_subevent(self):
         self.event.has_subevents = True
         self.event.save()