A bank letter is an official document from your bank that provides important information about your business' official bank account. This blog covers essential ACH authorization form requirements, including how to complete them correctly for smooth payment processes.Speak with your bank before setting up a debit payment. We will cover how to properly fill out an ACH form and how to submit the additional information required. Name and address of your bank as shown on the sample check above. Bank Routing Number, 9 Digit Bank Routing Number as shown on the sample check above. I'm freelancing for a new company and a junior accountant there is asking for me to provide my "bank information for ACH payment on a company letterhead." ACH is an electronic payment delivery system that allows you to pay or collect funds electronically through the ACH network. Investors are not required to fill out an FS Form 1199A. For a savings account, obtain a statement from your bank indicating the ACH routing number and account number.