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. It can be as simple as "we are closing your account as of X date.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. A letter of instruction is like your will's best friend. It's not a legal document. To close a bank account on behalf of someone who has passed away, you must have legal authority to manage the account. This letter is to inform you I am closing my accounts at your bank. 1. Simple application to bank manager for closing the account. To The Bank Manager, Name of the Bank, Address.