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.1. Look into granting financial power of attorney for limited transactions. Learn how to create an authorization letter to withdraw money from your bank easily. See return instructions at end of this form. Issuer: John Hancock Life Insurance Company (U. Do you know how to find out if you are a beneficiary on a bank account? How do I enroll in online banking?