Payoff requests, including borrower's authorization, should be directed to the servicer of the first mortgage. Do you need a loan payoff request form?Demand Letter Templates (22) – with Samples. 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. A payoff agreement is an informal contract in which a creditor agrees to accept the balance of a debt owed as full payment. 20 days of you paying off your mortgage in full, you should send your servicer a written notice of error. You should definitely keep the letter telling you that your loan was paid off in full. We'd also want you to keep at least the most current loan statement.