A promissory note is very similar to a loan. Each is a legally binding contract to unconditionally repay a specified amount within a defined time frame. However, a promissory note is generally less detailed and less rigid than a loan contract. For one thing, loan agreements often require repayment in installments, while promissory notes typically do not. Furthermore, a loan agreement usually includes the terms for recourse in the case of default, such as establishing the right to foreclose, while a promissory note does not.