Mistake

From the Latin from Latin mittere, 'to send' or 'to let go'.

In one sentence

A misunderstanding or error by one or both parties about a fact in a contract.

Plain English

A mistake in contract law means one or both parties got something wrong about an important fact when they made the deal. This could be a misunderstanding about what's being sold, the price, or some other key detail. Depending on whether both parties made the same mistake or only one did, the contract might be voidable (cancelable) or unenforceable. Courts look at whether the mistake was about something so central to the deal that the parties wouldn't have agreed if they'd known the truth.

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Example

Sarah buys what she thinks is a genuine antique painting for $5,000, but it turns out to be a worthless copy. If the seller also didn't know it was fake, both parties made a mutual mistake about a material fact, and Sarah might be able to cancel the sale.

Used in a sentence

“The contract was voidable because both parties made a mistake about the condition of the used car.”

Related terms

Unilateral Mistake

An error made by only one party to a contract about a material fact.

Unenforceable

A contract or clause that a court will not force either party to follow, even though it appears valid.

Implied Contract

A contract where the parties' intent to be bound is shown by conduct rather than explicit words.

Mutual Consent

Both parties freely agree to the same terms of a contract without pressure or misunderstanding.

Ambiguity

Unclear or multiple reasonable interpretations of contract language.

Offer

A proposal to enter into a binding agreement on specific terms.

Acceptance

Agreeing to the exact terms of an offer, creating a binding contract.

Consideration

Something of value exchanged by each party to make a contract binding.

This page is a plain-English reference and is not legal advice. Laws vary by jurisdiction and change over time. For specific situations consult a licensed attorney.