Mistake of Fact

In one sentence

A misunderstanding about something that actually exists or happened, rather than about the law itself.

Plain English

A mistake of fact is when someone gets the details of reality wrong—like thinking a painting is authentic when it's a forgery, or believing a car has never been in an accident when it has. This differs from a mistake of law, which is getting the rules wrong. Mistakes of fact can sometimes give you grounds to cancel a contract or get out of a deal, especially if both parties were mistaken or if one side deliberately hid the truth.

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Example

You buy a diamond ring believing it's a natural diamond, but it's actually lab-created. The seller knew the truth but didn't tell you. This mistake of fact about the ring's origin might let you rescind the contract if you can prove the seller was deceptive.

Used in a sentence

“Both parties' mistake of fact about the building's structural integrity made the contract voidable.”

Related terms

Mistake of Law

A misunderstanding about what the law says or requires, not about factual circumstances.

Material Fact

A fact that significantly affects a party's rights, obligations, or decision-making in a contract.

Fraud

Intentional deception or misrepresentation made to trick someone into entering a contract or deal.

concealment

The act of hiding or keeping secret something that should be disclosed, especially in legal matters.

Rescission

Unwinding a contract entirely, returning both parties to their positions before the deal.

Voidable Contract

A contract that one party can cancel or reject, but is otherwise valid.

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.

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.