A promissory note, sometimes referred to as a note payable, is a legal instrument (more particularly, a financing instrument and a debt 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 and conditions.

n. a written promise by a person (variously called maker, obligor, payor, promisor) to pay a specific amount of money (called "principal") to another (payee, obligee, promisee), usually to include a specified amount of interest on the unpaid principal amount (what he/she owes). The specified time of payment may be written as: a) whenever there is a demand, b) on a specific date, c) in installments with or without the interest included in each installment, d) installments with a final larger amount (balloon payment). A promissory note may contain other terms such as the right of the promisee to order payment be made to another person, penalties for late payments, a provision for attorney's fees and costs if there is a legal action to collect, the right to collect payment in full if the note is secured by real property and the property is sold ("due on sale" clause), and whether the note is secured by a mortgage or deed of trust or a financing statement (a filed security agreement for personal collateral called UCC-1). The promissory note is usually held by the party to whom the money is owed. There are legal limitations to the amount of interest which may be charged. Charging a rate in excess of the legal limit is called "usury," and this excess is legally uncollectible. When the amount due on the note, including interest and penalties (if any), is paid, the note must be cancelled and surrendered to the person(s) who signed it. A promissory note need only be signed and does not require an acknowledgement before a notary public to be valid. See also: interest obligee obligor usury