IOU

American  

Or I.O.U.

1. a written acknowledgment of a debt, especially an informal one consisting only of the letters IOU, the sum owed, and the debtor's signature.

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IOU British  

noun

1. a written promise or reminder to pay a debt

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IOU Cultural  

1. Abbreviation for “I owe you.” An IOU is a written statement of a borrower's obligation to pay a debt.

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Etymology

Origin of IOU

First recorded in 1610–20; representing I owe you

Example Sentences

Instead, the central bank created an IOU in 2022 that it calls a “deferred asset.”

From The Wall Street Journal • Mar. 25, 2026

Essentially, you borrow from the account and create an IOU to yourself.

From MarketWatch • Jan. 14, 2026

Should a player lose beyond his ability to pay, the others may allow him time to pay off his loss—usually, time until the next game—and he may offer up an IOU.

From The Wall Street Journal • Nov. 6, 2025

It says the IOU is "very much a real asset" as it is backed up by other group companies.

From BBC • Dec. 9, 2024

He’ll know something’s up in the same way he always knows which customer is going to shoplift or who’s good for an IOU and who’s not.

From "The Sun Is Also a Star" by Nicola Yoon