I think their "identity verification" routine may be one of those that asks questions only that person could answer.  "Which of these 3 companies financed your car in 2012?" "Did you once live in Altoona?" "Which of these names sound familiar?"  

So I think you would need the client sitting at your desk with you.  Maybe it could be done on the phone, but watch out for the dyslexics trying to read you account numbers.