What Is an IOU?
Let me tell you directly: an IOU, which comes from the phonetic sound of 'I owe you,' is a written acknowledgment of a debt between two parties. It originated as far back as the 18th century and is still widely used today as a less formal alternative to legally binding contracts. While it documents debt, its informal nature often leaves it open to interpretation and without the enforceability of formal agreements. You see, businesses and individuals frequently use IOUs as a starting point before moving to more detailed contracts.
How IOUs Work
IOUs are typically created on the spot, say at the end of a business meeting, as a memorandum of intent. They lack a standard format but should include basics like the date, amount, repayment date, involved parties, and the borrower's signature. You won't usually find details like interest, payment type, or consequences for nonpayment in them. Because of this informality, an IOU may not be legally binding or carry much weight in court, making legal remedies for nonpayment harder to enforce compared to formal agreements like promissory notes or bond indentures. This uncertainty means an IOU isn't usually a negotiable instrument that can be sold, transferred, or traded. If you need something more solid, downloadable templates can help create detailed IOUs, potentially making them more enforceable in court.
A Practical Example of an IOU
Consider this scenario: Smithco Bricks orders raw materials but doesn't have enough cash to pay for the entire order upon delivery. Instead, they make a down payment and issue an IOU promising to pay the rest within 30 days, with or without interest. If Smithco has an ongoing relationship with the supplier, this arrangement works fine for both sides. Remember, IOU is also used in other contexts, like describing bond issues or accounts receivable.
Special Considerations for IOUs
In accounting, a bookkeeper might record an outstanding debt as an IOU, counting it as an accounts receivable asset on the balance sheet. If the money is due in one year or less, it's a current asset; if more than a year, it's a long-term asset.
IOUs Compared to Promissory Notes
IOUs share similarities with promissory notes, as both are written agreements dealing with debt—the promise to repay a sum by a certain date. The key difference is that promissory notes are more formal and complete. They provide a due date, interest rate, payment schedule, repayment size, and often penalties for late payment. The term 'promissory note' must appear, and it's signed by both parties, sometimes witnessed and notarized. In short, promissory notes are more specific and serious than IOUs, standing up better in court. They're often used with mortgage or student loan agreements, and if unconditional enough, can be negotiable instruments. Be aware that promissory notes are subject to statutes of limitations for lawsuits, ranging from three to 15 years, starting from the breach date.
How to Write an IOU
You can write an IOU in many forms—typed, handwritten, even on a napkin. At minimum, include the borrower's name, lender's name, debt amount, current date, due date, and borrower's signature. I recommend adding how the debt will be repaid, a schedule if in installments, interest rate if any, a guarantor, governing state laws, and the lender's signature. You can find IOU forms and templates online to make this easier.
Frequently Asked Questions About IOUs
- What is an IOU in finance? It's a written, informal acknowledgment of debt between parties, often without specifics like schedules or interest, offering little legal recourse if unpaid.
- What is an example of an IOU? If your friend needs $1,500 for a deposit and you lend it, document that they owe you the amount with a repayment date—that's an IOU.
- Is an IOU a legal document? It can be introduced in court, but its binding nature is debated; more details make it more enforceable.
- Does an IOU need to be notarized? No, but notarization makes it more official and potentially more enforceable, like a promissory note.
The Bottom Line
An IOU is a written but informal contract recording a debt and repayment agreement, outlining basics but often lacking terms or schedules. It's not as binding as notarized contracts. You might use it for small sums between individuals or businesses with ongoing relationships, like vendors issuing short-term credit. Accountants can record these as IOUs in accounts receivable.
Other articles for you

Xenocurrency refers to any currency traded outside its home country's borders, often now called foreign currency or eurocurrency.

Levered Free Cash Flow (LFCF) is the cash remaining after a company meets its financial obligations, used for dividends, reinvestments, and indicating overall financial health.

The Savings and Loan Crisis was a major financial collapse in the 1980s and 1990s caused by deregulation, risky lending, and fraud, leading to over 1,000 institution failures and a massive taxpayer bailout.

Eminent domain allows governments to seize private property for public use with fair compensation.

A virtual assistant is a remote independent contractor providing administrative services to clients from a home office.

Technical skills are specialized abilities essential for job performance, and highlighting them effectively on resumes can improve your chances of passing AI screeners and impressing employers.

Land value represents the worth of a property including the land and its improvements, influenced by factors like location, demand, and risks.

A deposition is sworn testimony taken outside court during the discovery phase of a lawsuit to gather evidence and prepare for trial.

Capitalization in accounting involves recording costs as assets to spread them over time, and it also describes a company's mix of debt and equity funding.

The NAHB/Wells Fargo Housing Market Index (HMI) is a monthly survey gauging U.S