Sample Letter to Bank Informing the Death of the Account Holder. The death claim letter should be written in the formal letter format.This is to notify the bank that my. (Relationship with deceased). To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. Enter the 6 letters or numbers shown within the image above. Letters are not case-sensitive. Start the letter with your introduction and the reason for writing the letter. Name of Deceased had permanent legal residence at. Here's a simplified guide on how to fill in an Affidavit of Death in nine steps: Step 1: Identify the Type of Affidavit of Death: