A Payoff Letter memorializes a debtor and lender's agreement regarding a debt obligation's early payment and termination. A demand promissory note is a legally binding document between a borrower and a lender.The borrower promises to pay the debt whenever it is demanded. In consideration of full payment of the promissory note dated. Conclude your loan agreement once it's repaid. Use our release of promissory note template to formally mark your financial arrangement's end.