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.Creating a payoff letter is essential to any loan or mortgage repayment process. Our free templates and this guide can help you get started. A payoff agreement is an informal contract in which a creditor agrees to accept the balance of a debt owed as full payment. Include the loan or mortgage number. Create a Loan Payoff Letter online and download it as a PDF or Word document. Customize and print a blank Loan Payoff Letter for free. 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.