An IOU Document — the abbreviation standing for 'I Owe You' — is a simple written instrument in which one person (the Borrower) formally acknowledges in writing that they owe a sum of money to another person (the Lender) and promises to repay it on agreed terms. In England and Wales, a signed IOU is a legally binding simple contract: it creates an enforceable written record of the debt that the Lender can rely upon in County Court or High Court proceedings if the Borrower fails to repay.

An IOU performs several important legal functions. It prevents future disputes about whether money transferred between the parties was a gift or a loan. It records the exact amount of the debt in pounds sterling (GBP), stated in both figures and words to avoid any ambiguity. It specifies when and how the debt must be repaid — whether by a single payment on a fixed date, on written demand, or by instalments. It can record any agreed interest rate. And it provides the Lender with a document that can be presented to a court as evidence of the debt, which is essential given that most disputes about informal loans arise because no contemporaneous written record was created.

Under section 5 of the Limitation Act 1980, a creditor in England and Wales has six years from the date a simple contract debt became repayable to bring court proceedings to recover it. For a demand debt, the period runs from the date of the demand. Importantly, under section 29 of the Limitation Act 1980, a written acknowledgement of the debt or a part payment within the limitation period restarts the six-year clock — making this IOU itself an important legal document even if it is signed after the original debt arose.

An IOU Document is distinct from a Promissory Note (a formal negotiable instrument governed by the Bills of Exchange Act 1882), which can be transferred to a third party. An IOU is a simple contract between the original Lender and Borrower only. For most informal personal loans — whether between friends, family members, or business associates — an IOU Document is practical, accessible, and legally effective. Our template uses pounds sterling (GBP) and DD/MM/YYYY date format and is governed by the laws of England and Wales.

An IOU Document is appropriate in any situation where one person lends money to another informally and both parties wish to create a simple written record of the debt and its repayment terms, without the complexity of a full loan agreement.

Personal loans between friends and family members are the most common use case. When a friend lends money for a car, a family member advances funds to help cover an emergency, or a colleague covers someone's share of expenses with the expectation of repayment, an IOU provides a simple and accessible way to document the arrangement. Without such documentation, memories fade, amounts are disputed, and the question of whether money was a gift or a loan can cause lasting damage to personal relationships.

Employee loans and advances are another common context. Where an employer advances salary or provides a loan to help an employee cover an unexpected expense, an IOU or loan agreement creates a written record for payroll and accounting purposes and confirms the terms of repayment.

Small business debts between associates — for example, where one business partner covers a shared expense or advances money to another for a business purpose — may be documented with an IOU where a full loan agreement would be disproportionate to the amount involved.

Retrospective debt documentation is an important use case. Where money has already changed hands without any written documentation, an IOU can be signed at a later stage to retrospectively acknowledge and document the existing debt. This is particularly important where the Lender is concerned about the Limitation Act 1980 limitation period: the signing of an IOU within the six-year limitation period constitutes a written acknowledgement that restarts the clock under section 29 of the Act.

An IOU is not suitable for complex commercial lending arrangements, secured lending (where the lender takes security over the borrower's property or business assets), or transactions requiring FCA authorisation under the Consumer Credit Act 1974. In those cases, a more detailed loan agreement and specialist legal advice are required.

A well-drafted IOU Document for use in England and Wales should contain several key provisions that together make it legally enforceable and practically useful as evidence of the debt.

The parties clause clearly identifies the Lender and the Borrower by their full legal names, residential addresses (including postcode), and — where appropriate — contact details. Using full legal names is essential for enforcement purposes, as a County Court or High Court claim must identify the parties correctly.

The acknowledgement of debt clause is the core of the IOU. The Borrower formally acknowledges the existence of the debt, the amount (stated in both figures and words to prevent disputes about the amount), and the fact that the debt is a genuine, enforceable legal obligation under English contract law. The acknowledgement should confirm that the debt was not procured by duress, misrepresentation, or undue influence.

The origin of the debt section, while optional, is strongly recommended. Briefly describing how the debt arose — whether from a cash loan, unpaid goods, unpaid services, or another transaction — helps to identify the debt in the event of a dispute and confirms the nature of the transaction.

The repayment terms specify whether the debt is repayable in full on a fixed date, on demand, or by instalments. For instalment repayments, the schedule should state the exact amount, frequency, and first and last payment dates. An acceleration clause — providing that the entire outstanding balance becomes immediately due if any instalment is missed — is an important protective provision.

The interest provisions specify whether the debt accrues interest, the agreed annual rate, whether interest is simple or compound, and the date from which it accrues. For commercial debts between businesses, the Late Payment of Commercial Debts (Interest) Act 1998 may impose statutory interest at 8% per annum above the Bank of England base rate on overdue amounts.

The default clause defines what constitutes a default, the notice procedure, and the Lender's remedies — including the right to accelerate the outstanding balance and pursue recovery through the County Court or the High Court under the Civil Procedure Rules 1998, and the potential to serve a statutory demand under the Insolvency Act 1986.

The Limitation Act 1980 notice reminds both parties that the Lender has six years to bring proceedings and that a written acknowledgement or part payment within that period restarts the limitation clock — making the IOU document itself legally significant as an acknowledgement.

The governing law clause confirms that the IOU is governed by the laws of England and Wales, ensuring the correct legal framework applies to interpretation and enforcement of the document.