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HomeCommercial CodeDiv. 1Ch. 3§ 1303 Trade Conduct Definitions

§ 1303 Trade Conduct Definitions

Commercial Code·California
AI Summary·Official Text·Key Terms·Related Statutes·References
AI SummaryVerified

§ 1303 Trade Conduct Definitions

Key Takeaways

  • •If two people or businesses do the same thing over and over in their deal, and the other side knows and doesn’t complain, that’s called a 'course of performance.' It can help explain what their deal really means.
  • •If two people or businesses have done things a certain way in past deals, that’s called a 'course of dealing.' It can help figure out what their new deal means.
  • •If there’s a common way of doing things in a certain job or business, that’s called a 'usage of trade.' It can help explain what a deal means, but you have to prove it exists.
  • •If the deal’s words and the way people act don’t match, the words usually win. But if people keep acting a certain way, that can change or add to the deal.

Example

A bakery orders 100 cookies every week from a supplier. The supplier always delivers 105 cookies, and the bakery never complains or pays extra.

Even if the contract says '100 cookies,' the fact that the supplier always sends 105 and the bakery accepts them without saying anything means the deal might really include those extra 5 cookies. This is a 'course of performance.'

AI-generated — May contain errors. Not legal advice. Always verify source.

Official Source
View on CA.gov

§ 1303 Trade Conduct Definitions

(a) A “course of performance” is a sequence of conduct between the parties to a particular transaction that exists if: (1) the agreement of the parties with respect to the transaction involves repeated occasions for performance by a party; and (2) the other party, with knowledge of the nature of the performance and opportunity for objection to it, accepts the performance or acquiesces in it without objection. (b) A “course of dealing” is a sequence of conduct concerning previous transactions between the parties to a particular transaction that is fairly to be regarded as establishing a common basis of understanding for interpreting their expressions and other conduct. (c) A “usage of trade” is any practice or method of dealing having such regularity of observance in a place, vocation, or trade as to justify an expectation that it will be observed with respect to the transaction in question. The existence and scope of such a usage must be proved as facts. If it is established that such a usage is embodied in a trade code or similar record, the interpretation of the record is a question of law. (d) A course of performance or course of dealing between the parties or usage of trade in the vocation or trade in which they are engaged or of which they are or should be aware is relevant in ascertaining the meaning of the parties’ agreement, may give particular meaning to specific terms of the agreement, and may supplement or qualify the terms of the agreement. A usage of trade applicable in the place in which part of the performance under the agreement is to occur may be so utilized as to that part of the performance. (e) Except as otherwise provided in subdivision (f), the express terms of an agreement and any applicable course of performance, course of dealing, or usage of trade must be construed whenever reasonable as consistent with each other. If such a construction is unreasonable: (1) express terms prevail over course of performance, course of dealing, and usage of trade; (2) course of performance prevails over course of dealing and usage of trade; (3) course of dealing prevails over usage of trade. (f) Subject to Section 2209, a course of performance is relevant to show a waiver or modification of any term inconsistent with the course of performance. (g) Evidence of a relevant usage of trade offered by one party is not admissible unless that party has given the other party notice that the court finds sufficient to prevent unfair surprise to the other party. (Added by renumbering Section 1205 by Stats. 2006, Ch. 254, Sec. 23. Effective January 1, 2007.)

Last verified: January 23, 2026

Key Terms

course of performancecourse of dealingusage of trade

Related Statutes

  • § 10202 Confirmatory Memoranda Terms
  • § 2202 Final Written Terms Supremacy
  • § 10301 Lease Contract Enforcement
  • § 10302 Lease Title And Possession
  • § 10303 Lease Transfer Restrictions

References

  • Official text at leginfo.legislature.ca.gov
  • California Legislature. Commercial Code. Section 1303.
View Official Source