Also known as: parol evidence rule · parole evidence · parol evidence
Written by attorneys · grounded in primary & secondary sources — see below
A substantive rule of contract law that renders inoperative prior written or oral agreements when the parties have adopted a writing as a complete and exclusive statement of their agreement. The rule applies only after a court determines as a preliminary question whether the writing is integrated. It does not bar evidence of later modifications or claims based on fraud or mistake.
Preston Pratt sold land to Phoenix Technologies under a contract with a merger clause declaring the writing complete. After closing the deed omitted an oral promise about fiber installation. Phoenix sued to enforce the promise. The court held the parol evidence rule and merger doctrine discharged the prior term because the deed became the sole measure of obligations.
Penelope Price and Peak Performance signed a forty-page supply contract with an integration clause after months of talks. Price later sought to enforce an earlier oral funding promise omitted from the writing. The court first determined the writing was completely integrated before applying the parol evidence rule to exclude the prior term.
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Peter Park conveyed land by absolute deed to Premier Manufacturing to secure a loan. A side letter stated the deed was only security and Park could redeem upon repayment. When Park tendered payment the grantee refused. The court admitted parol evidence to show the deed operated as a mortgage allowing redemption.
Pearl Porter executed a will prepared by her attorney that omitted a bequest she had directed. After her death heirs sought to introduce evidence of the drafting mistake. The court admitted the extrinsic evidence to establish the testator's true intent despite the signed writing.
Pavel Petrov signed a detailed loan agreement that omitted an earlier term sheet's interest cap. He later sued claiming the cap applied. The court refused to consider the prior term sheet because the signed writing was integrated and the parol evidence rule barred contradictory prior agreements.
Piper Patel signed a contract that set final terms after preliminary negotiations. She later attempted to enforce an earlier oral side agreement on price adjustments. The court held the signed writing was the complete agreement so the parol evidence rule rendered the prior understanding inoperative.
The court makes this determination as a preliminary question of law by examining the writing's completeness and any integration clause. If the writing appears to be a complete and exclusive statement of the parties' agreement it is treated as integrated and prior terms within its scope are discharged.
No. The rule governs only prior or contemporaneous agreements. Evidence of subsequent modifications remains admissible even when the original contract is integrated.
Evidence remains admissible to show fraud, mutual mistake, or collateral agreements not intended to merge into the deed. The rule does not extinguish independent promises whose performance occurs after closing.
Courts admit parol evidence to establish the true intent and treat the deed as a mortgage. The grantor retains the equitable right to redeem upon repayment and the grantee must reconvey.
…do not have the consequences that a decision to terminate a person's life does. At common law and by statute in most States, the parol evidence rule prevents the variations of the terms of a written contract by oral testimony. The statute of frauds makes unenforceable oral contracts to leave property by will, and statutes regulating the…