Complex Commercial Litigation

Contract Claims

Parol Evidence Rule

Parol Evidence Rule

Parol Evidence Rule

The parol evidence rule excludes extrinsic evidence offered to vary or contradict a final written agreement. Its application depends on whether the writing is integrated, which an integration or merger clause is strong evidence of.

Exceptions permit extrinsic evidence to show fraud, mistake, duress, conditions precedent, and to explain ambiguous terms.

Alternative Names:

Parol Evidence, Extrinsic Evidence Rule

Why it Matters?

This rule is what makes written contracts reliable and what defeats claims built on side promises and negotiation representations. The recurring plaintiff response is to plead fraudulent inducement, since fraud is an exception to the rule. Whether that workaround succeeds depends on the state and on whether the contract contains a specific non-reliance clause, which several jurisdictions enforce to bar exactly this theory.

Frequently asked questions

Does the parol evidence rule bar fraud claims?

What is an integration clause?