Say you have a mortgage and want to know exactly how much you'd need to pay to satisfy the loan. A mortgage payoff letter will tell you that magic number.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 is an example of a payoff letter used in a syndicated loan transaction. This payoff letter (including the defined terms such as Lenders,. 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. How to Complete a Satisfaction of Mortgage (3 steps). Identify the Parties; Fill and Sign; File and Record the Form. 1.