A
promissory note is a
legal instrument (more particularly, a
financial instrument), in which one party (the
maker or
issuer) promises in writing to pay a determinate sum of
money to the other (the
payee), either at a fixed or determinable future time or on demand of the payee, under specific terms. If the promissory note is unconditional and readily salable, it is called a
negotiable instrument.