Customer disputes several charges saying card was stolen. She notified us on 1/18. We gave provisional credit and filed with Mastercard who in turn reimbursed us. Now Mastercard took back the money from us since there are signed receipts of the transactions on 1/17. Since they are saying the transactions were legitimate can we do the same and get our money back from the customer? What if we believe it is her signature based on documents we have on file?

As long as you have complied with your investigation requirements under 1005.11, you may reverse the provisional credit if you have concluded that your customer did perform the transactions. Section 1005.11(d) will require that you notify the customer of your decision in writing and honor checks and debits up to the amount of the revoked credit (at no fee if they cause an overdraft) for 5 business days. Also, inform the customer that they may have copies of your documents if they request them.

Note that the fact that you lose a chargeback with MasterCard doe not give you carte blanche to decide against your customer. If the signature on the sales receipts is not your customer's, you must find in the customer's favor. MasterCard's Zero Liability policy overrides the Reg E liability schedule in 1005.6 and you customer's liability would be $0. The bank would absorb the liability in this situation.

From all I've heard the credit card companies accept almost any signature. And that may not be bad in that I have never signed a keypad and had it really look like my signature. You're holding packages, in a rush, writing with virtually no palm rest, etc...

I wouldn't want to base my decision solely on that signature. Does your consumer shop there, what was purchased, was it reasonable for your consumer to buy this, could your consumer have been there...