Depending on your lender, you may have to sign in to an online account, call a helpline, or send a formal letter to start the request process. There's probably an online form.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. After you receive your payoff quote, it's time to make your final payment. You can pay with a certified check or through a wire transfer from your bank. 1) Call the mortgage department and request an official principal payoff letter. Request a payoff quote. 1. Complete the Payoff Request Form in its entirety. Unsigned or incomplete requests will not be processed. 2.