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.There's probably an online form. A payoff letter shows the remaining balance on your mortgage, including fees, interest, etc. Learn more about what a payoff quote is and how to request one. A payoff letter provides instructions on how to pay off a loan with a lump sum before the loan term ends. Learn how payoff letters work. 1) Call the mortgage department and request an official principal payoff letter. Paying off your mortgage early can save money in the long run. With our mortgage payoff calculator, discover how much you could save on your mortgage.