Supplier Bank Account Duplicate Checker - "A record with this combination of values already exists"

Hi Guys

Long story, but where I am working our various procurement depts across the organisation are not communicating, so it is a free for all when it comes to maintaining their supplier records and specifically supplier bank details for making payments which can be in several different places.

This is obviously not ideal, but the local dept I am working with would like to enter bank details for their particular BU under sites using their BU so they are certain that they are correct for our BU, and they will be the default supplier bank details when our accounts payable team make payments .