We have tried to force in a duplicate entry whereby the supplier reference on an invoice is input twice, but the system does not reject a duplicate. Could I suggest you have a warning put here or something to prevent duplicates. At least a warning which could be over ridden if chosen to. Thank you.
We don’t enforce duplication rules here. Quite a number of existing users actually have duplicate references. We may add a warning later but there are no plans to prevent duplicate references.