Closing a bank account when someone passes away isn't difficult, as long as you have the right paperwork for the the teller or banker. A bank closure letter may be needed if you want to close a bank account without having to go to your bank's physical location.Gather documents you need. You will need: A certified copy of the death certificate. You will need account numbers and serial numbers of assets. A sample form of Waiver of Account is included in this website. Sub: Request to close an account due to death. Obtain your letters of testamentary in New York with ease. I would bring the death certificate to the bank so they know that the family member in question has died. Use USPS PO Boxes for business or personal use.