By including a per diem amount in the letter, the parties will not have to execute another payoff letter if the termination date. It typically details the principal balance, interest due as of that date, per diem, any late fees, etc.Please accept this as my authorization to issue a payoff statement to. Through an effective date of . To get a payoff letter, ask your mortgage lender for an official payoff statement and let them know what the projected closing date is.