Definition
An implied contract is a legally binding agreement whose terms are not stated explicitly by the parties but are instead inferred from their conduct, course of dealing, surrounding circumstances, or, in a distinct category, imposed by law to prevent injustice. The term covers two fundamentally different animals that share a name:
1. Contract implied in fact: A true contract in which mutual assent exists but is communicated through acts, conduct, or circumstances rather than words. The agreement is genuine — the parties behaved in a way that reasonably signals offer, acceptance, and consideration — but nothing was written or formally spoken. An employee who performs services at an employer's request, with both parties understanding compensation is expected, has an implied-in-fact contract for payment.
2. Contract implied in law (quasi-contract): Not a contract at all in the classical sense. No mutual assent is required or found. The law imposes an obligation on one party to pay or perform in order to prevent unjust enrichment. Courts treat it as a contract for remedial purposes only. The more precise modern term is quasi-contract or restitution, and most contemporary courts and treatises distinguish it sharply from implied-in-fact contracts, though historical sources often blur the line.
Common Confusion
The phrase "implied contract" has long served as an umbrella covering both implied-in-fact contracts and quasi-contracts (implied-in-law contracts), and the conflation creates real analytical problems. An implied-in-fact contract requires the same elements as any express contract — offer, acceptance, consideration, and mutual assent — and is enforced on contract theory. A quasi-contract requires none of these; it is an equitable remedy rooted in unjust enrichment and sounds in restitution, not contract. Mixing the two leads to misapplied defenses (the statute of frauds applies to implied-in-fact contracts; it generally does not defeat quasi-contractual recovery), misread precedent, and confused damage calculations. Researchers encountering "implied contract" in older opinions should determine which category the court actually meant before relying on the holding.
Core Elements
For an implied-in-fact contract, courts look for the same building blocks as express contracts, established through circumstantial evidence:
— Offer: One party's conduct that would lead a reasonable person to understand an offer was being made.
— Acceptance: The other party's conduct manifesting agreement to the terms.
— Consideration: A benefit conferred or detriment incurred on both sides.
— Mutual assent: An objective meeting of the minds, inferred from the totality of conduct and circumstances rather than explicit words.
— Intent: The parties' actions must be consistent with an intent to contract, not merely with a social or gratuitous exchange.
For a quasi-contract (implied-in-law), the operative elements shift entirely: (1) a benefit conferred on the defendant, (2) the defendant's knowledge or appreciation of the benefit, and (3) circumstances making it inequitable for the defendant to retain the benefit without compensation.
Why It Matters in Research
The two-class structure of implied contracts is the central research trap. Older American and English cases — and historical dictionaries including Rapalje & Lawrence — treat implied-in-law obligations as a subspecies of contract, which they are not by modern analysis. When you encounter a 19th- or early 20th-century case describing a defendant's "implied contractual obligation," you must read the surrounding analysis to determine whether the court found actual inferred assent or was simply using contract language to justify equitable relief. The remedy and the defenses differ, and the precedent value of such cases depends entirely on which category actually applied.
In employment law, implied contracts have acquired particular significance: employee handbooks, policy manuals, and oral assurances have been held in many jurisdictions to create implied-in-fact contracts limiting at-will termination. This is a heavily litigated area with substantial jurisdictional variation, and the corpus of employment cases on this point is largely 20th-century and later — older contract law sources will not address it.
Implied consent in criminal law (most commonly in DUI contexts) uses the word "implied" in a related but distinct statutory sense — a legal presumption attached to the act of driving, not a contract theory at all. Do not carry implied contract doctrine into implied consent analysis.
The quasi-contract line of cases connects directly to modern restitution and unjust enrichment doctrine. Researchers following implied-in-law threads into contemporary material should pivot to those search terms, as courts and treatises have largely abandoned "implied contract" as the descriptor for what they now call restitutionary claims.
Historical Dictionary Support
Rapalje & Lawrence (1883) articulates the two-class framework explicitly, dividing implied contracts into those "implied in law" and those "implied by the law from circumstances." Their entry uses the landlord's right of distress as an example of a contract implied in law — a choice that illustrates how broadly 19th-century lawyers stretched the contract concept to encompass obligations we would today classify as purely statutory or equitable. The dictionary's framing reflects the period's tendency to organize all civil obligations under contract theory for want of a more developed law of restitution. What Rapalje & Lawrence do not address is the analytical work of separating genuine inferred-assent contracts from judicially imposed obligations — a distinction that became doctrinally important in the 20th century and is now standard. Researchers relying on historical dictionary entries for implied contract doctrine should treat them as period snapshots of a doctrine mid-development, not as settled modern taxonomy.
Jurisdictional Note
Whether employee handbooks or employer policies create implied-in-fact employment contracts varies significantly by state. A majority of jurisdictions recognize the theory under some circumstances; a significant minority do not, or apply it very narrowly. Quasi-contract recovery is widely available but details of pleading and measure of recovery vary. Neither doctrine is governed by uniform federal common law outside specific federal statutory contexts.
Encyclopedia Cross-Reference
Contracts — Classification (Bilateral, Unilateral, Express, Implied, Quasi-Contract) (The Law Mind Contracts & Commercial Law Encyclopedia)
Breach of Implied Contract — Handbooks, Policies, and Promises (The Law Mind Employment & Labor Law Encyclopedia)
DUI — Implied Consent and Chemical Testing (The Law Mind Criminal Law Encyclopedia) [for the unrelated implied consent doctrine; included to flag the distinction]