To initiate this process, kindly have the authorized borrower complete and submit a payoff authorization form to our loan servicing department. A mortgage payoff letter can come in two forms.One form tells borrowers the remaining principal amount and interest they have to pay to close out the loan. Payoffs must be made via certified funds—wire transfer, money order, or cashier's check. Please do not send personal checks, certified personal checks, or cash. How do I get a payoff for one of my Fifth Third loans? Member Service Center ; Toll Free: 800-688-7228 ; Fax Line: 210-258-1543 ; Loan Extension Requests If you need to defer a payment, we understand and we can help. We have many quick and easy options to make your loan payments, including online banking, mobile banking, in branch, phone and mail. Loan Payment Mailing Address. Farm Bureau Bank Attn: Payment Processing PO Box 33427.