What Randy said could be true, that the customer never signed. In todays world it is hard to believe there are still people who are illiterate, but it does still happen. Also, there may a disability that the member may not be able to do more than make an X. You did not mention the account type, I'm assuming it is a deposit account, as you are worried about forgery. Have there been any withdrawals from the account? You could check the signature on the withdrawal form against the signature card. If there is true signature, then the customer never did sign the signature card, and you need to have it signed. If the withdrawal slips have the same mark, I hope the tellers are verifying identity.
As to procedures, we do not have any specific procedures regarding this. I would think as long as proper identification was obtained at opening, you should be covered.
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