Fix custom taxation without invoice addresses

src/pretix/base/models/tax.py

@@ -160,6 +160,7 @@ class TaxRule(LoggedModel):
 
     def get_matching_rule(self, invoice_address):
         rules = json.loads(self.custom_rules)
+        if invoice_address:
             for r in rules:
                 if r['country'] == 'EU' and str(invoice_address.country) not in EU_COUNTRIES:
                     continue

src/pretix/control/templates/pretixcontrol/event/tax_edit.html

@@ -51,6 +51,7 @@
                             checked in order and once the first rule matches the order, it will be used and all further rules will
                             be ignored. If no rule matches, tax will be charged.
                         {% endblocktrans %}
+                        {% trans "All of these rules will only apply if an invoice address is set." %}
                     </div>
 
                     <div class="formset" data-formset data-formset-prefix="{{ formset.prefix }}">