Answer:
No. If the check is counterfeit, it was not signed by your customer. Your bank is accountable for the item if it failed to return it as unauthorized within its midnight deadline.
Whether or not your are obligated to reimburse your customer for the item depends on the terms of your deposit agreement and whether the customer facilitated the forgery through lack of care, etc.
First published on BankersOnline.com 4/18/11