diff --git a/src/pretix/base/payment.py b/src/pretix/base/payment.py
index 04166c17b3..2876a2f6a2 100644
--- a/src/pretix/base/payment.py
+++ b/src/pretix/base/payment.py
@@ -149,7 +149,9 @@ class BasePaymentProvider:
             ('_fee_percent',
              forms.DecimalField(
                  label=_('Additional fee'),
-                 help_text=_('Percentage'),
+                 help_text=_('Percentage of the order total. Note that this percentage will currently only '
+                             'be calculated on the summed price of sold tickets, not on other fees like e.g. shipping '
+                             'fees, if there are any.'),
                  required=False
              )),
             ('_availability_date',