Utah Code § 70A-2-202: Final expression -- Parol or extrinsic evidence.

Terms with respect to which the confirmatory memoranda of the parties agree or which are otherwise set forth in a record intended by the parties as a final expression of their agreement with respect to such terms as are included therein may not be contradicted by evidence of any prior agreement or of a contemporaneous oral agreement but may be explained or supplemented:

(1) by course of performance, course of dealing, or usage of trade (Section 70A-1a-303) or by course of performance (Section 70A-2-208); and

(2) by evidence of consistent additional terms unless the court finds the record to have been intended also as a complete and exclusive statement of the terms of the agreement.