You can attach the signed authorization form below. What is a Payoff Agreement?A payoff agreement is an informal contract in which a creditor agrees to accept the balance of a debt owed as full payment. Beneficiary Bank ABA: IGH. Creating a payoff letter is essential to any loan or mortgage repayment process. Our free templates and this guide can help you get started. Contact Bank of Texas's dedicated customer support for exceptional service and personalized solutions. Start the New Year With Less Clutter. Cut down on clutter this year when you sign up for e-statements. Auto Loan Payoff Payments.