A promissory note is a written promise to pay a specified amount within a predetermined period of time at a specified amount of interest; it does not have to be notarized to be legally valid. You should sign only the original of a promissory note, which will likely be held by the lender. Once the note has been repaid, you are entitled to get back the original.
Promissory notes typically contain the following key points:
Learn more about promissory notes from the Securities Exchange Commission.