"Does the reject message tell you which partner is wrong..."

Thats a good question.  When a dependents SSN has an issue, theres a number on the rejection message that lets you know which dependent in the list (1, 2, 3, etc) has the issue....I wonder if theres anything similar with the partners?

Can you add a screen shot of the full rejection report? You can see/print the full report by highlighting the client in the EFCenter and hitting F12, you should see Rejected returns in the list.