The Vehicle Payoff Sample Letter form is a crucial document for individuals aiming to transfer their vehicle loan to the State Department Federal Credit Union. Edit, sign, and share payoff letter water online online.No need to install software, just go to DocHub, and sign up instantly and for free. A payoff agreement is an informal contract in which a creditor agrees to accept the balance of a debt owed as full payment. A vehicle payment plan agreement is a contract between a buyer and seller of a vehicle that agrees to installment payments. Explore PSECU auto loans, interest rates, and requirements. Calculate an estimated PSECU auto loan payment, start a PSECU auto loan application, and more. A vehicle payment plan agreement is a contract between a buyer and seller of a vehicle that agrees to installment payments. San Antonio, TX 78288. Security Service Corporate Headquarters 15000 IH 10 West San Antonio, TX 78249 ; General Mail P.O. Box 691510.