Doctrine of Mistake

In one sentence

A contract may be voided or reformed when both parties made a fundamental error about key facts.

Plain English

The doctrine of mistake allows a party to escape or fix a contract when both parties were wrong about something important at the time they signed. This is different from one party simply being careless or making a bad deal. The mistake must concern a basic fact that goes to the heart of the agreement—not just the value or quality of what's being exchanged. Courts distinguish between mutual mistake (both parties wrong) and unilateral mistake (only one party wrong), and are much more willing to help when it's mutual.

Ad slot

Example

A buyer and seller agree on the sale of a painting for $10,000, both believing it's an original by a famous artist. After signing, they discover it's a worthless forgery. Under the doctrine of mutual mistake, either party might void the contract because both were mistaken about the painting's authenticity.

Used in a sentence

“The doctrine of mistake allowed the buyer to cancel the land purchase when both parties discovered the property had a hidden easement.”

Related terms

Mutual Mistake

Both parties are wrong about a basic fact when they sign a contract.

Contract

A legally binding agreement between two or more parties to do or not do something.

Material Alteration

A significant change to a contract or document that affects its meaning or enforceability.

Contractual Intent

The parties' mutual intention to be legally bound by their agreement.

intent

The defendant's conscious purpose or knowledge that their actions would cause a particular result.

Express Warranty

A clear, direct promise about a product's quality, performance, or characteristics.

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.