The Payoff Amount and Per Diem Amount quoted herein are effective through December 31, 2020. Per diem is an allowance for lodging, meals, and incidental expenses.The US General Services Administration (GSA) establishes the per diem reimbursement rates. It typically details the principal balance, interest due as of that date, per diem, any late fees, etc. A 10day payoff refers to the time it takes for your new lender to pay off your old loans during a refinance. The first step is to get in touch with your lender or loan servicer. You can find their contact information on your monthly statements. (3). Prepare a log, and have everyone who receives a per diem sign the log sheet. (4). Per diem rates lookup Allowances for lodging, meal and incidental costs while on official government travel. By including a per diem amount in the letter, the parties will not have to execute another payoff letter if the termination date.