Also known as: extrinsic evidence bars · parol evidence rule
Written by attorneys · grounded in primary & secondary sources — see below
A rule of substantive contract law that renders inoperative prior agreements, whether written or oral, to the extent they contradict or add to the terms of a completely integrated writing. The determination whether an agreement is integrated occurs as a preliminary question for the court.
Emmett Egan signed a detailed subscription agreement with Elysium Media for cloud services priced by monthly active users. The writing contained an integration clause and appeared complete on its face. When Egan later offered negotiation emails to show the parties meant to exclude free trial users from the pricing metric, the court first examined the writing's completeness and specificity to decide whether it was integrated before considering the emails.
Edith Eberhardt and Eastern Electric executed a forty-page supply contract that fixed price, set maximum capacity, and included an integration clause. Eberhardt sought to enforce an earlier oral promise for interconnection funding that the writing never mentioned. Because the court had already classified the writing as completely integrated, the extrinsic evidence of the oral funding commitment was excluded.
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The court decides as a preliminary question before interpreting the contract or applying the parol evidence rule.
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No. Prior negotiations remain admissible to explain the meaning of an undefined term even when the writing appears integrated, so long as the evidence is not offered to contradict or add new terms.
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The omission can rebut the presumption of integration. A short writing that leaves out substantial negotiated protections is less likely to be treated as the parties' final expression of their entire agreement.
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Yes. Evidence that the parties discussed additional material terms before signing can establish that the writing was not adopted as a final and exclusive statement, preventing application of the bar.
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…The Borderland of Hearsay, 39 Yale L.J. 489 (1930). [^maj-5]: Dallas County analogizes the hearsay rule to such rules as the parol evidence rule ( Patterson-Ballagh Corp. v. Byron Jackson Co. , 9 Cir., 1944, 145 F.2d 786; Long v. Morris , 3 Cir., 1942, 128 F.2d 653, 141 A.L.R. 1041), privileges ( Munzer v. Swedish American Line ,…