diff --git a/organize/interfaces.py b/organize/interfaces.py
index d5e83f5..8202842 100644
--- a/organize/interfaces.py
+++ b/organize/interfaces.py
@@ -220,6 +220,15 @@ class IService(Interface):
                         'object (participant) may be assigned with one '
                         'registration by entering a corresponding number.'),
                 required=False,)
+    presetRegistrationField = schema.Bool(
+                title=_(u'Preset Registration Field'),
+                description=_(u'Check this field if the field for the number '
+                        u'of registrations should have a default of 1 '
+                        u'(instead of 0) or the corresponding checkbox '
+                        u'should be checked by default. This is only useful '
+                        u'if the service manager contains only a single service.'),
+                required=False,
+                default=False)
     allowDirectRegistration = schema.Bool(
                 title=_(u'Allow direct registration'),
                 description=_(u'When this field is checked participants '
diff --git a/organize/service.py b/organize/service.py
index af233ea..b18b794 100644
--- a/organize/service.py
+++ b/organize/service.py
@@ -102,6 +102,7 @@ class Service(object):
     allowRegWithNumber = False
     allowDirectRegistration = True
     waitingList = False
+    presetRegistrationField = False
 
     def __init__(self, name=None, title=u'', capacity=-1, **kw):
         self.name = self.__name__ = name