To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. The letters cite reasons for closure such as relocating, no longer needing the account, job changes, and death of an account holder.The first and foremost thing you must do to close a bank account upon the death of a loved one is to inform the bank of this death. Here is a format letter for closing the bank account. Make sure you understand the entire format before writing a letter for closing a bank account. You should produce the concerned Bank branch the death certificate from municipal authority as proof of that persons demise. Notify Bank of America. We'll ask you for the deceased customer's full legal name and Social Security number to identify their accounts. Welcome to Cadence Bank.