diff --git a/welco/qualif/models.py b/welco/qualif/models.py
index bf2ef4a..7962b26 100644
--- a/welco/qualif/models.py
+++ b/welco/qualif/models.py
@@ -34,7 +34,8 @@ class Association(models.Model):
     def push(self, request):
         # push validated request to wcs
         context = {}
-        context['user_id'] = self.source.contact_id
+        if self.source.contact_id:
+            context['user_id'] = self.source.contact_id
         context['channel'] = self.source._meta.app_label
         context['summary_url'] = request.build_absolute_uri(
                 reverse('wcs-summary', kwargs={'source_type': self.source_type_id,