diff --git a/xos/models/mcord.xproto b/xos/models/mcord.xproto
index bbbc84e..386bcdb 100644
--- a/xos/models/mcord.xproto
+++ b/xos/models/mcord.xproto
@@ -14,4 +14,5 @@
     required string imsi_number = 1 [max_length = 30, content_type = "stripped", blank = False, null = False, db_index = False];
     optional string apn_number = 2 [max_length = 30, content_type = "stripped", blank = True, null = True, db_index = False];
     optional int32 ue_status = 3 [max_length = 30, choices = "(('0', 'Detached'), ('1', 'Attached'))", blank = True, null = True, db_index = False];
+    optional string created_by = 4 [null = True, blank = True, gui_hidden = True];
 }
diff --git a/xos/models/models.py b/xos/models/models.py
index 6d9b60d..51d379f 100644
--- a/xos/models/models.py
+++ b/xos/models/models.py
@@ -32,4 +32,8 @@
         except self.DoesNotExist:
             pass
 
+        if self.is_new and not self.created_by:
+            # NOTE if created_by is null it has been created by XOS
+            self.created_by = "XOS"
+
         super(MCordSubscriberInstance, self).save(*args, **kwargs)