IOU Agreement Template: Debt Acknowledgment & Repayment

What is an IOU?

An IOU (short for "I owe you") is a short written document in which one party acknowledges that they owe a specific sum of money to another and states, at minimum, how much is owed and when or how it will be repaid. It is the simplest, most informal way to put a debt in writing.

An IOU does three jobs at once. It records that a debt exists and fixes the amount, so the parties cannot later disagree about the number. It identifies who owes whom, removing the "that was a gift, not a loan" argument. And it creates a dated, signed piece of paper the creditor can point to if the debt is disputed. Because it is deliberately brief, an IOU works best for straightforward arrangements between people who trust each other — friends, family, or small businesses — where the value is low to moderate and the terms are simple.

Is an IOU legally binding and enforceable?

Yes — an IOU can be a legally binding, enforceable contract, provided it meets the basic requirements every contract needs and the debt itself is genuine. Its informality does not make it unenforceable; its lack of detail is what causes problems.

To be enforceable, an IOU generally needs the same core ingredients as any contract:

• A clear debt. An identifiable sum acknowledged as owed by one named party to another.
• Consideration. Something of value changed hands (money lent, goods supplied, expenses covered). A bare promise to pay with nothing given in return can be treated as an unenforceable gift promise.
• Intent to be bound. Wording showing the debtor promises to repay, not merely a hope or moral obligation.
• Signature. Signed by the debtor at least; ideally both parties, dated.

A signed IOU serves as strong written proof of the debt if a dispute reaches court. What it usually lacks — a default clause, interest terms, a collection mechanism — is why a promissory note or loan agreement is better for larger sums.

IOU vs promissory note vs loan agreement — what's the difference?

All three record a debt, but they sit on a spectrum from informal acknowledgment (IOU) to a fully detailed, negotiable instrument (promissory note) to a comprehensive contract (loan agreement). The right choice depends on how much is at stake and how much protection the lender needs.

• IOU. The simplest. Acknowledges a debt and, at most, a basic repayment term. Rarely covers interest, default, collateral, or collection. Best for small, low-risk debts between people who trust each other.
• Promissory note. A more formal, standalone promise to pay that typically spells out interest, a payment schedule, late fees, default, and acceleration. In many states it is a negotiable instrument that can be transferred to a third party. Better for meaningful sums where the lender wants enforceable terms.
• Loan agreement. The most comprehensive — a full contract with representations, covenants, default and remedy clauses, collateral or security, governing law, and dispute resolution. Used for larger, more complex, or higher-risk loans.

See the side-by-side table below for enforceability, level of detail, and when to reach for each.

What should an IOU include?

Even a short IOU should capture six essentials. Each one closes off an argument a debtor could otherwise raise later.

1. The parties. Full legal names and contact details of the debtor (who owes) and the creditor (who is owed), so there is no ambiguity about who is bound.
2. The amount. The exact sum owed, ideally in both figures and words ("$2,500 (two thousand five hundred dollars)"), plus the currency.
3. The reason. A brief description of why the debt exists (personal loan, reimbursed expenses, rent advanced, business advance). This establishes consideration and rebuts a "gift" defense.
4. The date. The date the IOU is signed — and, if different, the date the money was actually lent, which starts the clock on interest and the statute of limitations.
5. Repayment terms. Either a single due date or a simple installment schedule (number of payments, amount, frequency, first due date), plus payment method.
6. Signatures. The debtor's signature is essential; the creditor's signature and any witnesses strengthen the document.

Optional but valuable additions: an interest rate (or an express "interest-free"), a late-fee provision, and a note on what happens on default. Sample wording for these is in the clause library below.

Does an IOU need witnesses or notarization to be valid?

No. In almost all cases an IOU is valid and enforceable with just the debtor's signature — witnesses and a notary are not legally required for an ordinary personal debt. They are useful, not mandatory.

What witnesses and notarization actually add is evidentiary strength, not legal validity:

• Witnesses can later confirm the debtor signed voluntarily and was the person who signed, which undercuts a "that isn't my signature" or "I was pressured" defense.
• Notarization has a notary verify the signers' identities and attest that they signed, making the document much harder to challenge as a forgery and often smoother to use in court.

For small IOUs between friends, a plain signed document is normally fine. As the amount grows, add two witnesses and consider notarizing. Note that a few situations do carry formal requirements — for example, some states' statute of frauds requires certain agreements to be in writing, and a loan secured by real property involves separate formalities — so confirm locally for anything beyond a simple unsecured debt.

Can you charge interest on an IOU, and is there a limit?

Yes, you can charge interest if both parties agree to it in writing — but every state sets a ceiling through its usury laws, and those ceilings vary widely, so the safe move is to confirm your state's cap before setting a rate.

A few reliable principles apply nationwide:

• Interest-free is always safe. If you charge no interest, no usury cap can be breached. Many personal IOUs are best kept interest-free.
• Interest must be agreed and stated. If the IOU is silent, most states presume no interest until a judgment (though a "legal rate" may then apply). To charge interest, write the annual rate into the document.
• Usury caps vary a lot by state. Limits differ from state to state and by loan type. For example, California's general usury limit is 10%, Florida's is 12%, and New York treats interest above 16% as civil usury and above 25% as criminal usury for most loans between individuals. Some states (such as Arizona, Utah, and Texas) let a written contract set a higher rate than the default. Because the numbers genuinely differ — confirm your state's usury limit locally rather than assuming a figure.

Charging above the cap can cost you the interest, and in some states the whole loan or even criminal exposure. When in doubt, stay modest or interest-free, and get the rate confirmed for your state.

What happens if they don't pay the IOU back?

You escalate in steps — a written reminder, then a formal demand letter, and if that fails, a lawsuit, usually in small claims court for smaller amounts. But you must act within your state's statute of limitations, which is the deadline to sue on the debt.

The practical sequence:

• Written reminder. A polite note referencing the IOU and the missed date often resolves it.
• Demand letter. A firmer written demand stating the amount, the deadline, and that you will pursue legal collection if unpaid. This also documents your effort.
• Small claims court. For modest sums (limits vary by state, commonly in the $2,500-$25,000 range) you can sue without a lawyer. A signed IOU is strong evidence.
• Formal suit or judgment enforcement. For larger debts, a civil suit; if you win, a judgment can be enforced through wage garnishment or liens where the law allows.

Mind the clock. The statute of limitations on a written debt varies significantly by state — roughly 3 years in states such as Delaware, Maryland, North Carolina, and South Carolina, up to 10 years in states such as Illinois, Indiana, and Iowa, and as long as 15 years in Kentucky. Once it expires, you generally lose the right to sue, so confirm your state's deadline early. Making a partial payment or acknowledging the debt in writing can, in some states, reset that clock — a detail worth checking before you accept a partial payment.

Need a customized IOU agreement?

Use AI Lawyer to generate one tailored to your situation. Set the parties, the amount and reason, whether it is interest-free or interest-bearing, and a single due date or installment schedule; the assistant produces a clean, readable IOU with the essentials in place — acknowledgment of debt, repayment terms, late-payment and default language, and signature and optional witness or notary blocks. For larger debts, business loans, or anything secured by property, have a licensed attorney review before signing, and confirm your state's interest cap and limitations period.