Sample Letter to Bank Informing the Death of the Account Holder. The death claim letter should be written in the formal letter format.A valid governmentissued ID. The death certificate of the account holder. The account owner's social security number. To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. This is to notify the bank that my. (Relationship with deceased). This guide covers some things to look for in a Will and how to proceed without one later. Online: Use our online form to notify us about a customer's death. Learn about estates, how to file an estate, and the administrative process.