diff --git a/src/pretix/control/views/event.py b/src/pretix/control/views/event.py
index a4eba10f2..e671ca055 100644
--- a/src/pretix/control/views/event.py
+++ b/src/pretix/control/views/event.py
@@ -1104,6 +1104,7 @@ class TaxCreate(EventSettingsViewMixin, EventPermissionRequiredMixin, CreateView
         }
 
     def post(self, request, *args, **kwargs):
+        self.object = None
         form = self.get_form()
         if form.is_valid() and self.formset.is_valid():
             return self.form_valid(form)