The first step in using an ACH authorization form is to request this form from your bank or financial institution. Setting up an ACH requires a savings or checking account, routing number, and bank account number.1. Select your payment frequency: â–¡ Recurring Payment: Authorize regularly scheduled debits from your checking account. I,. , authorize the Wake Tech. A bank letter is an official document from your bank that provides important information about your business' official bank account. I am writing to request a direct deposit form for my paycheck. A domestic (US) bank account will be required in order to sign up for ACH payments. An ACH authorization form is a legallyrequired agreement that is required in order to execute an ACH payment, which is a type of electronic funds transfer. You'll need to enter the recipient's bank account, deposit amount, and payment frequency. Confirm the details and start the ACH direct deposit.