Material Alteration

In one sentence

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

Plain English

A material alteration is when someone changes something important in a contract or document without permission, in a way that changes what it means or what people owe each other. This can make the document unenforceable or give the innocent party a legal claim. The key is that the change has to be significant—fixing a typo isn't material, but changing a price or date usually is.

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Example

After you and a seller sign a purchase agreement for a house at $300,000, the seller secretly changes the price to $350,000 on their copy. This material alteration means the document no longer reflects what you both agreed to, and you likely won't be bound by the changed version.

Used in a sentence

“The court ruled that the material alteration of the contract's payment terms made the entire agreement unenforceable.”

Related terms

Substantial Breach

A failure to perform a contract that goes to the heart of the deal.

forgery

The crime of falsely making, altering, or imitating a document or signature with intent to defraud.

concealment

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

Breach of Warranty

Failing to fulfill a promise or guarantee made about a product or service.

Objective Theory of Contracts

The legal rule that contract meaning is based on what a reasonable person would understand, not secret thoughts.

Severability

A clause allowing a contract to remain valid even if one part is found unenforceable.

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.