Cosigned promissory notes are a financial instrument that are usually signed by two or more people. They are a legal agreement in which the cosigners agree to share responsibility for the debt of the person borrowing the money. Synonyms for cosigned promissory notes may include joint promissory notes, co-signed notes, co-borrower notes, and co-signed loans. These terms are often used interchangeably, and they all refer to the same type of financial agreement. When someone is looking for a loan, using a cosigner is a common way to get approved. This is because the lender is taking less risk when there are multiple parties responsible for the debt.