Formal Authorization Letter to Bank for Money Withdrawal Dear Sir, I am writing in context with my account number 444-555-666 with your prestigious bank. You can write a letter, sign it and hand it to a bank professional.They will accept the letter but, may still have you sign their form. Contact your bank for a power of attorney form. Permission for the company to take automatic payments out of your bank account. This is called "revoking authorization. A cheque book was issued with the account? Fill a cheque in (with appropriate signatures). To Whom It May Concern,.