In this article, the author analyzes the rules that govern the legal effectiveness of oral agreements that purport to modify written contracts. The article includes a discussion of four situations that raise difficult questions of whether oral agreements should be regarded as pre-written contract agreements (rather than as subsequent oral modifications) for purposes of the parol evidence rule. The author concludes that no doctrinal changes are called for in the contract formation timing rules currently applicable to these situations unless such changes are accompanied by broader judicial enforcement of no-oral-modification clauses.
Ohio Northern University Law Review
Gregory Scott Crespi, Clarifying the Boundary between the Parol Evidence Rule and the Rules Governing Subsequent Oral Modifications , 34 Ohio N.U. L. Rev. 71 (2008)