four corners of an instrument

“Four corners of an instrument” is the principle in contract law that a document’s meaning should be derived from the document itself, i.e., from its language and all matters encompassed in it. According to this principle, information that does not appear in the document (extrinsic evidence)such as the circumstances surrounding the document or the history of the parties signing itmust not be analyzed or relied upon to ascertain the document’s meaning. 

[Last reviewed in September of 2021 by the Wex Definitions Team]

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