A written promise to pay back a sum of money at a specific time

When you borrow money to buy a home, you must sign a promissory note, which outlines the loan's terms and sets the due date. The most common type of promissory note is called the installment note. This says that your monthly payment must be applied to both the loan's principal and interest. The promissory note enforces the document that secures the property as repayment for the loan, either called a deed of trust or mortgage depending on where your home is. Promissory notes are commonly called notes or IOUs.

See: Mortgage, Deed of trust