Integration Rule Law and Legal Definition
Integration rule is a principle that if the parties to a contract have embodied their agreement in a final document, then any other action or statement is without effect and is immaterial in determining the terms of the contract.
The integration rule is also a complete bar to the use of parol evidence to insert a term into a contract that the parties neither bargained for nor agreed to include. However, the integration rule is not always an iron wall. The integrated documents barrier may be penetrated by evidence tending to show that the documents are not, in fact, complete.[Sax v. DiPrete, 639 F. Supp. 2d 165, 170 (D. Mass. 2009)].