By including a per diem amount in the letter, the parties will not have to execute another payoff letter if the termination date. Please include a per diem amount in the statement.Please email this information to as soon as possible. A payoff agreement is an informal contract in which a creditor agrees to accept the balance of a debt owed as full payment. The release is what removes the lien, which in your case isn't there. By setting up Auto Pay in MyAccount online or on the GM Financial Mobile app, you can have your payments automatically withdrawn from your bank account. And receiving reimbursement for your actual per diem costs up to the locality rate for the OCONUS location. Closing Costs Financed (Paid from your Loan Amount)?