In contract law, an offer is a clear expression of willingness to enter into a deal, communicated in a way that would lead a reasonable person to understand their agreement is being sought and would close the arrangement.1H2O. Restatement (Second) of Contracts Sections 3, 17, 18, 22, 23, 24 It is the starting point of every agreement. Once a valid offer exists, the person who receives it holds the power to create a binding contract simply by accepting. For that power to exist, the proposal has to meet three basic requirements: its terms must be definite enough to enforce, the person making it must appear genuinely committed, and the intended recipient must actually know about it.
What Makes a Proposal a Legal Offer
Three conditions have to line up before a proposal rises to the level of an enforceable offer. Miss any one of them and there is nothing a court can hold anyone to.
Definite Terms
A proposal only counts as a legal offer if its terms are specific enough that a court could figure out what the parties agreed to and determine whether either side broke the deal.2H2O. Restatement (Second) of Contracts Section 33 If the details are too vague, there is nothing to enforce, and courts will not write the agreement for you. The level of detail needed depends on the type of transaction, but a few core terms almost always matter:
- Who is involved. The offer has to identify the person making the promise and the person being invited to accept. Without that, a court cannot assign rights or obligations.
- What is being exchanged. The subject matter needs enough description to distinguish it from other items or services. A proposal to sell “a car” is usually too vague; identifying the make, model, and year clears the bar.
- Price. Under traditional common-law rules, a valid offer typically states the exact dollar amount or provides a clear formula for calculating it.
- Timing. The offer should indicate when performance must happen, whether that is a delivery date, a completion deadline, or some other time frame.
Different bodies of law set different bars for how precise these terms must be. Everything above reflects the traditional common-law standard. When the deal involves selling goods rather than services or real estate, the Uniform Commercial Code loosens things considerably, as explained further below.
Serious Intent, Measured Objectively
Courts do not try to read anyone’s mind. Instead, they look at outward words and behavior and ask how a reasonable person in the recipient’s shoes would have interpreted them.3Columbia University. Restatement of Contracts (Second) Selected Sections If the external signals point to a serious commitment, the law treats it as one, even if the speaker privately had no intention of following through. This “objective” approach protects anyone who reasonably relied on what they heard or read.
The same standard filters out statements no reasonable person would take seriously. Someone shouting during an argument that they would sell their house for a dollar has not made an offer. The extreme mismatch in value and the obvious emotional context tell any reasonable listener this is not a genuine proposal. Jokes, offhand remarks, and expressions of frustration fall outside the line for the same reason.
Communication to the Offeree
A proposal does not become an active offer until the intended recipient actually knows about it. Contract law requires that both parties show their agreement with reference to each other’s expressions, meaning there must be a genuine meeting of the minds.1H2O. Restatement (Second) of Contracts Sections 3, 17, 18, 22, 23, 24 Without that awareness, no one can meaningfully accept.
The classic illustration involves rewards. If you find and return a lost pet without knowing a reward had been posted, you generally cannot claim the money under common-law rules. You performed the act, but you did not do so in response to the offer, so no contract formed at the time of your action.
What Doesn’t Qualify as an Offer
Plenty of statements that sound deal-adjacent do not actually create the power to accept. Three categories come up most often.
Preliminary negotiations. Not every conversation about a potential deal creates an offer. A statement like “I might be willing to sell my business for the right price” is a preliminary negotiation, not a binding proposal. A statement does not qualify as an offer if the recipient knows, or should know, that the speaker does not intend to close the deal without further discussion.1H2O. Restatement (Second) of Contracts Sections 3, 17, 18, 22, 23, 24 Social invitations, requests for bids, and letters of intent marked “non-binding” typically land here. The key question is whether the words invite immediate acceptance or merely open the door for more negotiation.
Most advertisements. An ad listing a product at a certain price is treated as an invitation for customers to come make their own offers, not as a binding promise to sell. The reasoning is practical: a typical ad reaches an unlimited audience, and holding the advertiser to a contract with every person who responds could create far more obligations than the seller has inventory to fill. There is a narrow exception. When an advertisement is clear, definite, and specific, leaving nothing open for negotiation, it can cross into a binding offer. A famous case involved a store that advertised a specific fur coat for one dollar on a first-come, first-served basis; the ad was detailed enough that the first qualifying customer could accept just by showing up.
Jokes and emotional outbursts. As noted above, the objective standard screens these out. A statement that no reasonable person would take seriously is not an offer, no matter how it is phrased.
Bilateral and Unilateral Offers
Offers come in two basic forms, and the type determines how the other party accepts.
A bilateral offer asks for a return promise. When you offer to sell your laptop for $500, you are looking for the buyer to promise to pay. The moment both sides exchange promises, a contract exists. This is the most common structure in everyday transactions.
A unilateral offer asks for a completed action rather than a promise. A posted reward of $200 for the return of a lost dog is the textbook example. No contract forms until someone actually returns the dog. Until that performance happens, the offeror is not yet bound. Reward advertisements fit the same mold: anyone who performs the requested act with knowledge of the reward has accepted, and the person who posted it must pay.
The distinction matters most when it comes to revocation. With a bilateral offer, the offeror can generally revoke any time before the other party promises to accept. With a unilateral offer, a special protection kicks in: once the offeree has started performing the requested act, the offer becomes temporarily irrevocable, giving the offeree a reasonable chance to finish the job.
Offers for the Sale of Goods Under the UCC
When a deal involves the sale of goods — physical, movable items like equipment, inventory, or raw materials — the Uniform Commercial Code applies instead of common-law rules. The UCC takes a more flexible approach to offer formation. A contract for sale can be made in any way that shows the parties reached an agreement, including through their conduct, and a deal does not fail just because one or more terms were left open.4Legal Information Institute. UCC Section 2-204 Formation in General The only requirements are that the parties intended to make a contract and that there is a reasonably certain basis for a remedy if something goes wrong.
This flexibility shows up most clearly in how the UCC handles missing terms. If the parties do not settle on a price, the UCC fills the gap with a reasonable price at the time for delivery.5Legal Information Institute. UCC Section 2-305 Open Price Term If no delivery location is specified, the default is the seller’s place of business.6Legal Information Institute. UCC Section 2-308 Absence of Specified Place for Delivery If no timeline is set, the law fills in a reasonable time.7Legal Information Institute. UCC Section 2-309 Absence of Specific Time Provisions These built-in defaults, called gap fillers, let a deal between merchants survive with fairly skeletal terms.
One term the UCC will not fill in for you is quantity. If the parties do not specify how many goods are involved, there is no contract. A court can approximate a fair price or a reasonable delivery window, but it has no basis for guessing how many units someone intended to buy. When drafting an offer for goods, nailing down the quantity is the single most important detail.
These gap-filler rules only apply when both sides genuinely intended to close a deal. If the parties agreed specifically that there would be no contract unless they settled on a price and then failed to do so, the UCC will not force a contract into existence.5Legal Information Institute. UCC Section 2-305 Open Price Term
When an Offer Cannot Be Revoked
Ordinarily, an offeror can pull back an offer at any time before acceptance. Certain arrangements lock the offer in place for a set period.
Option Contracts
In an option contract, the offeree pays something of value (or provides other consideration) in exchange for the offeror’s promise to keep the offer open. Once the offeror accepts that payment, revocation is off the table for the agreed period.
Firm Offers for Goods
When the transaction involves goods and the offeror is a merchant — someone who regularly deals in that type of product — the UCC provides a special rule. A merchant who puts an offer in a signed writing and states that it will be held open cannot revoke it, even without any payment from the offeree.8Legal Information Institute. UCC Section 2-205 Firm Offers The irrevocable period lasts for the time stated in the writing or, if none is stated, for a reasonable time, but it cannot exceed three months. If the “held open” language appears on a form provided by the offeree rather than the offeror, the merchant must separately sign that specific term.
Part Performance of a Unilateral Offer
When an offer calls for acceptance through a completed action, the offer becomes irrevocable once the offeree begins performing. The offeror must then give the offeree a reasonable opportunity to finish.
Detrimental Reliance
Under the doctrine of promissory estoppel, a court may prevent an offeror from revoking if the offeree reasonably and foreseeably relied on the offer to their detriment and justice requires enforcement. This situation arises most often in construction bidding, where a general contractor relies on a subcontractor’s bid to put together a larger proposal. The subcontractor cannot pull the bid after the general contractor has committed to a project based on it.
How an Offer Ends
An offer does not stay on the table forever. It can lose its force through any of several mechanisms, each with its own rules.9H2O. Restatement (Second) of Contracts Section 36
Revocation by the Offeror
The offeror can withdraw the offer at any point before the offeree accepts, as long as the revocation is actually communicated.3Columbia University. Restatement of Contracts (Second) Selected Sections A revocation takes effect when the offeree receives it, not when the offeror sends it. Until the offeree knows the offer has been pulled, they still have the power to accept. The protections described in the previous section (option contracts, firm offers, part performance, and reliance) all limit or eliminate this revocation power.
Rejection and Counter-Offers
The offeree can end the offer by turning it down. A flat rejection immediately kills the original offer, even if the offeree later changes their mind. A counter-offer has the same effect: it simultaneously rejects the original proposal and creates a new one with different terms.10H2O. Restatement (Second) of Contracts Section 39 Once a counter-offer is on the table, the original disappears and cannot be revived unless the original offeror restates it.
A related concept is the mirror image rule, which applies in common-law transactions but not sales of goods under the UCC. Under this rule, an acceptance must match the offer exactly: same price, same terms, same conditions. If the “acceptance” changes even one term, it is not an acceptance at all. It is a counter-offer, and the original offer is dead. The UCC softens this requirement for goods transactions, allowing an acceptance to create a binding contract even if it includes added or different terms.
Lapse of Time
If the offer sets a deadline for acceptance, it expires automatically when that deadline passes.9H2O. Restatement (Second) of Contracts Section 36 When no deadline is specified, the offer remains open only for a reasonable time, which depends on the circumstances. An offer to buy perishable goods or volatile commodities might expire within hours, while an offer to purchase real estate could remain open for days or weeks. The more time-sensitive the subject matter, the shorter the window.
Death or Incapacity
If either the offeror or the offeree dies or becomes legally incapacitated before acceptance, the offer terminates automatically.9H2O. Restatement (Second) of Contracts Section 36 No notice is required; the termination happens by operation of law. The rationale is that a contract is a personal commitment, and that commitment cannot be finalized once one of the parties no longer has the legal capacity to follow through.