I work in a bank. We obtain the right thumb print of a non-customer cashing an on-us check. If they don’t have a right thumb, we get their left thumb, if that’s not available, we choose any finger. I don’t think we’ve ever been faced with an armless person. I’ll have to see what our policy is regarding that....
It certainly is an interesting problem, isn’t it. I’d be interested in what your bank tells you.