By including a per diem amount in the letter, the parties will not have to execute another payoff letter if the termination date. The first step is to get in touch with your lender or loan servicer.You can find their contact information on your monthly statements. It typically details the principal balance, interest due as of that date, per diem, any late fees, etc. Per diem is an allowance for lodging, meals, and incidental expenses. The US General Services Administration (GSA) establishes the per diem reimbursement rates. Below is a list of effective dates for the Handbook changes: Changes identified in previously published. Provides that commissioners may receive per diem as well as expenses incurred in duties. 31 Powers; application of EDA law. Subd. 1. Discover more about per diem interest—the daily interest on a loan that occurs outside of the standard repayment period.