- Définition :
An unconditional promise in writing made by one person to another, signed by the maker, engaging to pay, on demand or at a fixed or determinable future time, a sum certain in money, to, or to the order of, a specified person, or to bearer. [GDT]

- A promissory note is a form of debt – similar to a loan or an IOU – that a company may issue to raise money. Typically, an investor agrees to loan money to the company for a set period of time. In exchange, the company promises to pay the investor a fixed return on his or her investment, typically principal plus annual interest. [SEC]