diff --git a/input/forms.py b/input/forms.py
index 5582b06..2272b60 100644
--- a/input/forms.py
+++ b/input/forms.py
@@ -76,41 +76,29 @@ class IFGForm(FdbForm):
         fields = ['cost', 'url', 'notes']
 
 
-'''TODO: the next four classes could maybe have a common base class for the check field,
-but i am not sure about the sequence of fields. check should be always last'''
-class LiteratureForm(FdbForm):
+class CheckForm(FdbForm):
+    """Baseclass for all classes which need a check for Nutzungsbedingungen"""
     check = BooleanField(required=True,
                          label=format_html("Ich stimme den <a href='{}'>Nutzungsbedingungen</a> zu",
                          NUTZUNGSBEDINGUNGEN))
 
+class LiteratureForm(CheckForm):
     class Meta:
         model = Literature
         fields = ['cost', 'info', 'source', 'notes']
 
-class EmailForm(FdbForm):
+class EmailForm(CheckForm):
     # TODO: add some javascript to show/hide other-field
-    check = BooleanField(required=True,
-                         label=format_html("Ich stimme den <a href='{}'>Nutzungsbedingungen</a> zu",
-                         NUTZUNGSBEDINGUNGEN))
-
     class Meta:
         model = Email
         fields = ['domain', 'address', 'other']
 
-class BusinessCardForm(FdbForm):
-    check = BooleanField(required=True,
-                         label=format_html("Ich stimme den <a href='{}'>Nutzungsbedingungen</a> zu",
-                         NUTZUNGSBEDINGUNGEN))
-
+class BusinessCardForm(CheckForm):
     class Meta:
         model = BusinessCard
         fields = ['project', 'data', 'variant', 'sent_to']
 
-class ListForm(FdbForm):
-    check = BooleanField(required=True,
-                         label=format_html("Ich stimme den <a href='{}'>Nutzungsbedingungen</a> zu",
-                         NUTZUNGSBEDINGUNGEN))
-
+class ListForm(CheckForm):
     class Meta:
         model = List
         fields = ['domain', 'address']