By including a per diem amount in the letter, the parties will not have to execute another payoff letter if the termination date. A payoff letter provides instructions on how to pay off a loan with a lump sum before the loan term ends.Learn how payoff letters work. Please accept this as my authorization to issue a payoff statement to. Through an effective date of . To start the process upload the completed Loan Payoff Notice Form into DMS along with the following documents. " The Borrower's written payoff request. Please provide payoff information for the above referenced mortgage. Also, please provide loan number and per diem interest. Per diem interest is used to charge daily interest for the days that fall between a loan closing date and when repayment is scheduled to begin.