diff --git a/tailbone/views/customers.py b/tailbone/views/customers.py
index c5cc9fd8..e25018e4 100644
--- a/tailbone/views/customers.py
+++ b/tailbone/views/customers.py
@@ -243,6 +243,15 @@ class CustomersView(MasterView):
             f.set_renderer('groups', self.render_groups)
             f.set_readonly('groups')
 
+    def unique_id(self, node, value):
+        query = self.Session.query(model.Customer)\
+                            .filter(model.Customer.id == value)
+        if self.editing:
+            customer = self.get_instance()
+            query = query.filter(model.Customer.uuid != customer.uuid)
+        if query.count():
+            raise colander.Invalid(node, "Customer ID must be unique")
+
     def objectify(self, form, data=None):
         if data is None:
             data = form.validated
@@ -385,6 +394,7 @@ class CustomersView(MasterView):
 
 
 # TODO: this only works when creating, need to add edit support?
+# TODO: can this just go away? since we have unique_id() view method above
 def unique_id(node, value):
     customers = Session.query(model.Customer).filter(model.Customer.id == value)
     if customers.count():