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Course of Dealing

A prior pattern of transactions between the same contracting parties used, under an applicable legal rule, to interpret or supplement their current agreement.

Version
v1 · 2026-10-25 · History
Domain-specific #
14375
Domain group
Professional & Organizational Practice
Origin domain
Law & Governance
Subdomains
Contract Law, Commercial Contracts → Law & Governance

Core Idea

A course of dealing is a relevant pattern in previous transactions between the same parties that may help give meaning to their present agreement. Under UCC §1-303(b), the earlier sequence must fairly establish a common basis of understanding; §1-303(d) describes how it may give meaning to, supplement, or qualify terms.[1] The legal effect depends on the governing rule and the facts. It does not follow merely because the parties have dealt before.

Scope of Application

The UCC distinguishes a course of dealing from performance under the current transaction and from a trade-wide usage.[1] A freight-service court also used prior invoices to interpret a later oral shipping agreement; that decision was outside its UCC Article 2 goods-sale analysis.[2] An international equipment-sales award used a practice established between the parties under CISG Article 9(1) for a spare-parts obligation in individual sales, while excluding the distributorship agreement as such from the CISG.[3] These are distinct legal settings, so one setting's rule is not automatically the other's.

Clarity

Identify the same parties, the earlier transactions, the repeated conduct, the fair inference of shared understanding, the current term or obligation, and the applicable legal rule. UCC §1-303 treats the earlier transactions, current performance, and wider trade usage as separate sources of evidence.[1] An isolated current act is not a prior course of dealing. An industry custom without the particular parties' own history is a different category.

Manages Complexity

The order of inquiry matters. First locate the relevant earlier conduct. Next ask whether it fairly conveyed a shared basis. Finally ask what present issue the governing rule permits it to affect. Under the UCC, express terms and the interpretive sources are construed consistently where reasonable; its conflict order applies when that is not reasonable.[1] That UCC order is not a universal law for other regimes.

Abstract Reasoning

  1. State the current agreement and governing law.
  2. Separate previous dealings of the same parties from present performance or trade practice.[1]
  3. Test whether the previous conduct fairly supports a common understanding rather than counting repetitions alone.[1]
  4. Connect that understanding to the particular present term or obligation.[1]
  5. Apply the legal rule's limits to the result.[1]

Knowledge Transfer

The same questions help compare freight services and individual international sales: who acted before, what the other party could understand, and which later obligation is disputed. The source of legal authority and its limits must be checked in each setting.[2][3]

Example

In NNR Aircargo, NNR sent Dunlop invoices with the same liability limit for 47 earlier freight-service transactions.[2] Their later shipment was arranged orally, and the invoice for it came after the cargo was stolen.[2] The Ninth Circuit treated the earlier invoices as a sufficient course of dealing to supplement the silent oral agreement.[2] The parties' previous transactions, notice from repeated invoices, disputed later liability, and applicable judicial analysis each have a distinct role. The number 47 is a fact of this case, not a required threshold.

Neighborhood in Abstraction Space

Course of Dealing sits in a moderately populated region (57th percentile for distinctiveness): it has near-neighbors but no dense thicket of look-alikes.

Family — Competitive Strategy & Market Entry (11 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-25

Not to Be Confused With

  • Course of performance: repeated conduct under the current transaction, with the further UCC conditions for knowledge and acceptance or acquiescence.[1]
  • Usage of trade: a regular practice of a trade or place, whether or not these parties dealt before.[1]

  • Judicial precedent: earlier decisions used as legal authority, rather than the parties' own earlier transactions.

  • Patent prosecution history: a Federal Circuit concurrence used the phrase for an applicant's exchanges with the Patent Office and how they can inform patent-term meaning; the majority distinguished patents from contracts.[4] It is an adjacent patent context, not an instance of the bilateral contract-law identity here.

The UCC distinguishes an agreement's bargain-in-fact from the total legal obligation called a contract.[5] Course of dealing can help establish what the parties agreed; it is not itself a bundle of breach rules, remedies, and enforcement obligations.

References

[1] American Law Institute & Uniform Law Commission. Uniform Commercial Code § 1-303. Subsections (a)–(f), course of performance, course of dealing, and usage of trade. registry ↩a ↩b ↩c ↩d ↩e ↩f ↩g ↩h ↩i ↩j

[2] United States Court of Appeals for the Ninth Circuit. Insurance Company of North America v. NNR Aircargo Service (USA), Inc. (2000), 201 F.3d 1111, factual history and Discussion I–III. https://law.justia.com/cases/federal/appellate-courts/F3/201/1111/642791/ registry ↩a ↩b ↩c ↩d ↩e

[3] ICC Court of Arbitration. Award 8611/HV/JK (1997), original German, facts and spare-parts analysis; English abstract is a translation aid. https://www.unilex.info/cisg/case/229 registry ↩a ↩b

[4] United States Court of Appeals for the Federal Circuit. Markman v. Westview Instruments, Inc. (1995), 52 F.3d 967, majority p. 985 and Mayer concurrence p. 991. https://openjurist.org/52/f3d/967 registry ↩

[5] American Law Institute & Uniform Law Commission. Uniform Commercial Code § 1-201. Subsections (b)(3) and (b)(12), agreement and contract. registry ↩