What makes a power of attorney a legal document?

A bank does not have to accept a POA. My mother's bank would only accept a POA on their letterhead that was notarized by one of their tellers. That was their legal department's policy. A bank does not have to do business with you. You are free to take your business elsewhere. I hope this information is helpful. I recommend that you use a probate or elder law attorney to assist you. Trying to "do it yourself" usually is a mistake. Estate planning is complex and can cause all sorts of unexpected problems. Please don't try to save a nickel -- it usually costs $10 to fix a nickel problem!

Just stop. These are inexpensive documents that should be drafted by an expert, namely, an estate or elder law attotrney. There is a skill involved in doing them and knowing what the law requires. Get an expert and do this now.

The bank has the right to have requirements before accepting certain documents. You have the choice on who you do business with.