Please accept this as my authorization to issue a payoff statement to. Through an effective date of .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. What is a Payoff Agreement? A payoff agreement is an informal contract in which a creditor agrees to accept the balance of a debt owed as full payment. A borrower fills out the full application form only once per project, at the initial application for. The stable and reliable flow of income is a key consideration in mortgage loan underwriting.