A Letter: Mortgage Payoff 1st Mtg is a document that is sent to a mortgage lender, usually by a borrower, when they are paying off their first mortgage. This letter should include the borrower's name and address, the loan amount, and the date of payoff. It should also include the name and contact information of the borrower's lender, as well as any other relevant information. Depending on the situation, there may be different types of Letter: Mortgage Payoff 1st Mtg, such as a Refinance Payoff Letter, or an Escrow Payoff Letter.