What Is a Promissory Note? How to Write One That Holds Up
A promissory note is a written, signed promise by one party to pay a specific sum to another — on demand or on a set schedule. It turns "I'll pay you back" into an enforceable record that both sides can rely on.
This guide explains what a promissory note is, the terms it must contain to hold up, and how it compares to a full loan agreement or a casual IOU.
What a promissory note is
A promissory note documents a debt: who owes, who is owed, how much, and on what terms it will be repaid. It is simpler than a full loan agreement but far stronger than a verbal promise or a scribbled IOU.
People use promissory notes for personal loans between family or friends, seller-financed purchases, and small business borrowing — anywhere the terms need to be clear and enforceable without a bank.
Terms every promissory note needs
To be enforceable, a promissory note should state, in plain terms:
- The principal — the amount borrowed.
- The interest rate, if any, and how it is calculated.
- The repayment schedule: lump sum on a date, or installments.
- What happens on late or missed payments (late fees, default).
- Whether it is secured by collateral or unsecured.
- The date, and signatures of the borrower (and lender).
Secured vs unsecured, and interest
An unsecured note relies on the borrower's promise alone. A secured note is backed by collateral — a car, equipment, or property — that the lender can claim on default; note the collateral clearly if so.
If you charge interest, keep the rate within your state's legal limit (usury caps vary). A zero-interest note is fine between family, but state it explicitly so there is no ambiguity.
Promissory note vs loan agreement vs IOU
An IOU merely acknowledges a debt exists. A promissory note adds an enforceable promise to repay on defined terms. A full loan agreement goes further with detailed covenants, representations and remedies, used for larger or commercial loans.
For most personal and small-business lending, a well-drafted promissory note is the right middle ground — clear and enforceable without the overhead of a full agreement.
Frequently asked questions
Is a promissory note legally binding?
Yes. A promissory note signed by the borrower, stating the amount and repayment terms, is an enforceable contract in every US state. Keeping it in writing is what makes the debt collectible.
Does a promissory note need to be notarized?
Notarization is not usually required for enforceability, but it strengthens the note by making the signature harder to dispute. Some parties notarize larger notes as a precaution.
What is the difference between a promissory note and a loan agreement?
A promissory note is a borrower's promise to repay on set terms — simpler and shorter. A loan agreement is a two-sided contract with detailed covenants, used for larger or commercial loans.
How do I write a promissory note?
Use PaperKit's free Promissory Note maker to enter the amount, interest and repayment schedule and generate a clean, signable PDF that documents the debt clearly.