What It Does
For in-house counsel, this distinction decides which document your company gets held to when a relationship breaks down. The signed agreement is one source of evidence. Your business unit's conduct, invoices, calls, and accepted practices may also become evidence of the parties' agreement.
A practical test: pull the last three amendments, purchase orders, and email approvals on any live vendor relationship and ask whether the pattern they show matches the signed terms. Where the pattern and the paper diverge, you have implied-term exposure. Then identify whether the counterparty is asserting an implied-in-fact term inside the contract or a quasi-contract claim outside it.
An express contract fixes the terms in words, so a dispute turns on interpreting the language the parties chose.
An implied-in-fact contract binds the parties on terms a court infers from their conduct, and it carries the same enforceability as a signed agreement.
An implied-in-law contract gives a court a restitution remedy where no agreement exists, measured by the value of the benefit conferred rather than by expectation damages.
An integration clause makes the writing the exclusive statement of the deal and limits what prior oral understandings a court will consider.
A course-of-dealing exclusion opts out of the Uniform Commercial Code default that lets prior conduct supplement the express terms of a goods contract.
Recent SEC supply agreements pair integration clauses with separate exclusions for course of performance, course of dealing, and usage of trade, showing that drafters treat these as distinct risks.
When You'll See It
Vendor and services relationships: An expired master services agreement or SOW may continue through invoices, approvals, and deliveries. That conduct can support an implied-in-fact contract even when the paper says the term ended.
Goods contracts under the UCC: UCC sections 1-303 and 2-202 let course of performance, dealing, and trade usage explain or supplement a goods contract unless the writing excludes them.
Employment: Offer letters, handbooks, and codes may create implied duties. In Woolley v. Hoffmann-La Roche, the New Jersey Supreme Court held that a manual's job-security promise binds unless it prominently says the provisions are nonbinding. Review the at-will acknowledgment.
Settlement and litigation posture: Complaints often plead express and implied contract, unjust enrichment, and quantum meruit in the alternative. That mix signals uncertainty about which writing controls.
Integration and course-of-dealing clauses decide how much outside conduct a court may consider. The risk grows with the length of the vendor relationship.
Implied-in-fact and implied-in-law claims need separate analysis. An implied-in-fact contract is inferred from conduct and requires offer, acceptance, intent, and consideration.
An implied-in-law claim is quasi-contract, imposed to prevent unjust enrichment, and supports restitution when no contract covers the subject.
Examples
The Wendy's Company / Kenneth W. Gilbert
Marketing Consulting Agreement
Integration clause
Mutual
2025
"This Agreement constitutes the complete and exclusive statement of the terms and conditions between the parties, and supersedes and merges all prior proposals, understandings and all other agreements, oral and written, between the parties relating to the subject matter of this Agreement."
Magna New Mobility USA, Inc. / Serve Operating Co.
Master Services Agreement
Express mutual promises
Mutual
2024
"NOW THEREFORE, in consideration of the foregoing premises and the mutual covenants contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties agree as follows ... Magna hereby retains Serve and Serve agrees to provide to Magna, from time to time, the services described in one or more statements of work in the form attached as Schedule A hereto"
Allegion / Jeffrey Braun, Offer Letter for Senior Vice President
General Counsel and Secretary
No implied contract acknowledgment
One-Sided
2024
"Please understand that this letter does not constitute a contract of employment for any specific period of time but will create an "employment at-will" relationship. This means that the employment relationship may be terminated with or without cause and with or without notice at any time by you or Allegion. Allegion reserves the right to modify or amend the terms of your employment at any time for any reason. This document does not create an express or implied contract of employment."
Chemtura Corporation / TETRA Technologies, Inc.
Bromine Requirements Sales Agreement
Course-of-dealing exclusion
Mutual
2022
"No modification or waiver of the terms or conditions hereof shall be binding upon Buyer or Seller unless approved in writing by an authorized representative of such party ... The course of performance, course of dealing or usage of trade shall not be used to interpret, construe, qualify, modify, explain or supplement any of the terms hereof."
MannKind Corporation / United Therapeutics Corporation
Research Agreement
No rights granted by implication
One-Sided
2018
"This Agreement does not convey any ownership or other rights in any Prototype Formulation or MannKind Intellectual Property Rights embodied therein by implication, estoppel or otherwise except for the rights expressly granted in Article 4."
Getaround, Inc. / Broadspire Services, Inc.
Confidential Settlement Agreement
Implied contract and quasi-contract claims recital
Mutual
2024
"WHEREAS, on April 29, 2021, Broadspire filed a Cross-Complaint against Getaround asserting several claims concerning Getaround's lack of payment to Broadspire beginning in October 2019, including breach of implied contract, unjust enrichment, and quantum meruit;"
Negotiate
You want the signed document to be the whole deal, and you want conduct outside it to stay outside it.
Pair the integration clause with a separate provision excluding course of performance, course of dealing, and usage of trade. The two address different mechanisms, and the Uniform Commercial Code treats them separately in sections 2-202 and 1-303.
Use the words "complete and exclusive statement," which is the phrase section 2-202(b) keys on when a court decides whether consistent additional terms come in.
Require amendments and waivers in a signed writing, and add that a failure to enforce any provision does not waive it, so a pattern of accommodation does not become a term.
In any rights grant, state that nothing is conveyed by implication or estoppel beyond what the agreement expressly grants, as the MannKind research agreement does.
Close the gap between term expiration and continued performance by fixing renewal mechanics in the contract. Performing past the stated term is the most common way an implied-in-fact contract gets created in a commercial relationship.
You want the relationship as it was performed to count, and you want a remedy available where the paper falls short.
Push back on a blanket course-of-dealing exclusion in a long-running supply relationship, and narrow it so trade usage can still explain ambiguous terms rather than supplement them.
Preserve equitable claims in any release you sign, because a release that sweeps in unjust enrichment and quantum meruit takes away your fallback if the express contract turns out to be unenforceable.
Document the pattern while it is happening, through invoices, acceptance emails, and approvals. An implied-in-fact contract has to be proved with evidence of conduct and mutual intent rather than with a signature.
Ask for an express provision covering the work you are already doing outside the statement of work. A court will not construct a quasi-contract where an express contract already covers the subject matter.
Where a signed contract's scope is genuinely contested, plead breach of express contract, breach of implied contract, and unjust enrichment in the alternative. That is what both sides did in the Getaround and Broadspire dispute above.
This doctrine turns on language that is easy to miss in a fast read. The integration clause, course-of-dealing exclusion, no-waiver provision, and "by implication, estoppel or otherwise" carve-out may sit in four different places. GC AI's Playbooks hold those positions, and GC AI for Word checks a draft against them inside the document you are redlining.
Red Flags
An entire agreement clause with no course-of-dealing exclusion in a goods contract, which leaves the section 1-303 default in place and lets prior conduct supplement the terms you thought were final.
Continued performance after a stated term expires with no renewal or holdover provision, which invites an implied-in-fact contract on terms a court picks rather than terms you drafted.
A handbook, code of conduct, or offer letter with job security language and a disclaimer buried in the back matter, since Woolley conditions the disclaimer's effect on prominence.
A release that discharges unjust enrichment and quantum meruit claims alongside contract claims when you are the party owed money. It removes the restitution fallback you would need if the express contract failed.
A rights grant that lists what is licensed and stays silent on what is withheld, which leaves room for an implied license argument that the express grant was meant to foreclose.
FAQs
This content is for informational purposes only and does not constitute legal advice.
