Edit, sign, and share sample payoff letter for private mortgage online. No need to install software, just go to DocHub, and sign up instantly and for free.This is a sample Florida mortgage payoff authorization form and should not be used or relied upon for any real estate transaction. 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. This guide will help you learn mortgage math, allowing you to confidently calculate how much you need to pay off your mortgage.