What regulation would a customer violate if a valid address is not provided on their account. In example, an accountholder that is on return mail due to the post office returning their statements because the address that is on file is incorrect.

I didn't think customers could violate a regulation, but off the top of my head, look at your CIP policy for updating addresses. if you think the incorrect address was given intentionally, pass the information to your fraud department.

Did you not validate the address during your CIP procedures? Sounds like a red flag to me that something is terribly wrong with the account and customer. You might want to exercise your right to close the account..

We have some customers that move every time the rent is due. We lock their debit card which usually brings an immediate response. On a new account, we would close immediately.