A contract in which one party accepts or rejects the terms of the other party’s offer is the standard model for how binding agreements form: one side proposes, the other side responds, and the answer decides everything. If the response is a clear, unconditional yes on the exact terms proposed, a contract exists and both sides are bound. If the response is a no, a change, a delay, or nothing at all, no contract exists and neither party owes the other anything. Most contract disputes turn on which side of that line a particular response fell on.
What Counts as a Valid Acceptance
Acceptance has to be a clear, unconditional yes to the terms of the offer. Under the common law’s mirror image rule, your acceptance must match the offer exactly. Change the price, the deadline, or the scope of work, and you haven’t accepted. You’ve made a counteroffer, which the original offeror can take or leave, and the original offer is dead unless the offeror revives it.
The Uniform Commercial Code loosens this rule for sales of goods. Under UCC ยง 2-207, a response that adds or changes terms can still count as acceptance rather than a counteroffer, unless the response is expressly conditional on the other party agreeing to the new terms.1Cornell Law School Legal Information Institute. UCC 2-207 – Additional Terms in Acceptance or Confirmation This matters because in real commercial deals, purchase orders and acknowledgment forms almost never match perfectly.
Ways to Accept an Offer
Acceptance can happen in several ways, and the method matters both for proving the contract exists and for determining when it took effect.
- Express acceptance. You explicitly agree to the terms, either verbally or in writing. Signing a purchase order, sending an email that says “I accept your offer,” or verbally agreeing to a price all qualify. This is the clearest form and the hardest to dispute.
- Implied acceptance. Your actions demonstrate agreement even though you never said the word “yes.” If a contractor receives a written proposal and immediately begins the work described in it, that conduct implies acceptance. Courts look for a clear pattern; isolated or ambiguous actions won’t cut it.
- Acceptance by performance. Some offers invite acceptance through performance rather than a promise. Delivering goods that were ordered, or completing a task described in a reward offer, can be acceptance. The UCC specifically recognizes that an offer to buy or sell goods can be accepted “by a prompt promise to ship or by the prompt or current shipment of conforming or nonconforming goods.”2Cornell Law School Legal Information Institute. UCC 2-206 – Offer and Acceptance in Formation of Contract
Regardless of method, the UCC’s general rule is that an offer to make a contract invites acceptance “in any manner and by any medium reasonable in the circumstances,” unless the offer itself says otherwise.2Cornell Law School Legal Information Institute. UCC 2-206 – Offer and Acceptance in Formation of Contract
When Acceptance Takes Effect
Timing can decide whether a contract exists. Under the mailbox rule, which is the default in most states, acceptance becomes effective the moment you send it, not when the other party receives it. Drop an acceptance letter in the mail on Monday and the contract forms Monday, even if the letter doesn’t arrive until Wednesday.
The rule has limits. It applies only when you use an authorized method of communication. It does not apply to option contracts, where acceptance takes effect only when the offeror actually receives it. And the offeror can override the rule entirely by specifying that acceptance isn’t effective until received.
The rule also doesn’t protect you if you send a rejection first and then change your mind. If your rejection arrives before your later acceptance, the rejection controls. If you’re accepting an important offer, use a fast and verifiable method.
Conditional Acceptance and Counteroffers
When someone responds with “I accept, but only if…” that’s a conditional acceptance, and it usually functions as a counteroffer rather than a true acceptance. The original offeror then has to agree to the new terms before any contract exists. In Ardente v. Horan, a buyer’s acceptance letter that requested certain furniture be included with a property sale was held to be conditional, so no contract was ever formed.3Justia Case Law. Ardente v Horan – 1976 – Rhode Island Supreme Court Decisions
Conditional acceptance is common in real estate, where buyers routinely accept offers contingent on financing approval, satisfactory inspections, or the sale of their current home. The seller can accept the conditions, reject them, or propose changes. Until both sides agree on every term, no binding contract exists.
In commercial transactions involving goods, the UCC takes a more practical approach through its “battle of the forms” rules. A written acceptance that includes additional terms still operates as an acceptance, not a counteroffer, unless the acceptance is expressly conditional on the other party agreeing to the new terms. Between merchants, additional terms automatically become part of the contract unless the original offer limited acceptance to its exact terms, the additions would materially change the deal, or the offeror objects within a reasonable time.1Cornell Law School Legal Information Institute. UCC 2-207 – Additional Terms in Acceptance or Confirmation
When Silence Counts as Acceptance
As a general rule, silence is not acceptance. No one can force you into a contract by mailing you a proposal and declaring that your failure to respond means you agree. Courts recognize a few narrow situations where silence can bind you.
If you receive services with an opportunity to reject them and reason to know the provider expects payment, keeping quiet and enjoying the benefit can bind you. If previous dealings between you and the offeror established a pattern where silence meant agreement, a court may hold you to that pattern. A buyer who has repeatedly received and kept shipments of goods without objection may be found to have accepted a new shipment through silence, because the prior course of dealing made silence meaningful.
The offeror can also state that silence will be treated as acceptance, but this only works if the offeree actually intends to accept by staying silent. An offeror cannot unilaterally declare “if I don’t hear from you by Friday, we have a deal” and bind an unwilling party.
Unsolicited Goods
Federal law protects you here. If a company mails you merchandise you never ordered, you can treat it as a free gift. You have no obligation to pay for it or send it back, and the sender is prohibited from billing you or sending collection notices. The only exceptions are free samples clearly marked as such and charitable solicitations. Sending unordered goods and then demanding payment is an unfair trade practice under federal law.4Office of the Law Revision Counsel. 39 USC 3009 – Mailing of Unordered Merchandise
Acceptance in Digital Transactions
Most contracts people encounter today form online, and courts have developed specific rules for how digital acceptance works.
Clickwrap Agreements
Clickwrap agreements require you to click an “I agree” button before proceeding. Courts generally enforce these as valid acceptance, provided the terms are clearly presented and accessible before you click. The key factor is whether you had a meaningful opportunity to review the terms and took an affirmative action to accept them.
Browsewrap Agreements
Browsewrap agreements post the terms somewhere on the website, usually via a link at the bottom of the page, and treat your continued use of the site as acceptance. Courts are far more skeptical. In Nguyen v. Barnes & Noble, the Ninth Circuit held that a browsewrap agreement was unenforceable because the user had no actual notice of the terms. The court found that a hyperlink buried at the bottom of the page, without any prompt for the user to take affirmative action, was insufficient to create constructive notice, even when the link sat near buttons the user had to click.5United States Court of Appeals for the Ninth Circuit. Nguyen v Barnes and Noble Inc
Electronic Signatures
Under the federal E-SIGN Act, a contract or signature cannot be denied legal effect solely because it is in electronic form.6Office of the Law Revision Counsel. 15 USC 7001 – General Rule of Validity An e-signature on a digital contract carries the same weight as a handwritten signature on paper. Both parties must consent to conducting the transaction electronically, and electronic records need to remain accessible for later reference.
What Rejection Looks Like
When no one accepts, there is no contract and neither party has any enforceable obligations. But the way non-acceptance happens matters, because different forms carry different consequences.
Outright Rejection
If you flat-out reject an offer, your power to accept it is gone. You can’t call back a week later and say you changed your mind. The offer is terminated. The only way to move forward is if the offeror makes the offer again or makes a new one. A statement like “I’ll think about it” is not a rejection, but “no, that doesn’t work for me” is.
Counteroffer
A counteroffer operates as both a rejection of the original offer and a new offer rolled into one. Once you counter, the original offer is off the table. The other party now holds the power to accept or reject your counteroffer. If they reject it, neither of you is bound to anything unless someone makes a fresh proposal.
Lapse of Time
Every offer has a lifespan. If the offeror sets a deadline, the offer expires when the deadline passes. If no deadline is stated, the offer remains open for a “reasonable time,” which depends on the circumstances. An offer to sell perishable goods has a much shorter reasonable period than an offer to sell real estate. An oral offer made in conversation generally must be accepted immediately. Once time runs out, the offer dies automatically and any late attempt to accept has no effect.
When the Offeror Pulls the Offer Back
An offeror can generally revoke an offer at any time before acceptance. The revocation must be communicated to the offeree; you cannot secretly revoke an offer and then claim it was off the table when the other party tries to accept. Revocation takes effect when the offeree learns of it, not when the offeror decides to revoke. Two exceptions cut off that power.
Option Contracts
An option contract is a separate agreement where the offeree pays something, or provides other consideration, in exchange for the offeror’s promise to keep the offer open for a set period. During that window, the offeror cannot revoke. Real estate deals frequently use option contracts: a developer might pay $5,000 for the right to purchase a parcel within 90 days, and if the developer decides to buy within that period, the seller must honor the original terms.
Firm Offers Under the UCC
For sales of goods, the UCC creates a special rule for merchants. A merchant who makes a signed, written offer that promises to stay open is bound by that promise, even without consideration, for the time stated, up to a maximum of three months. If no time is stated, the offer stays open for a reasonable period, but never more than three months. If the assurance language appears on a form the offeree supplied, the offeror must separately sign that specific term for the firm offer to be enforceable.7Cornell Law School Legal Information Institute. UCC 2-205 – Firm Offers
Death or Incapacity
An offer automatically terminates if either the offeror or the offeree dies or becomes legally incapacitated before acceptance. The offer is considered personal to both parties. A deceased offeror’s estate is not bound by an offer the offeror never saw accepted, and no one steps into the shoes of a deceased offeree to accept. Option contracts backed by consideration are the exception because they are already binding agreements in their own right.
Who Has the Legal Capacity to Accept
Even a perfectly formed acceptance can fail if the person accepting lacks legal capacity.
Minors
In most states, anyone under 18 can enter into contracts, but those contracts are voidable at the minor’s option. The minor can disaffirm the deal at any time before turning 18 or within a reasonable time after reaching adulthood. The adult on the other side cannot disaffirm; only the minor has that right.
When a minor disaffirms, they’re generally entitled to a refund of whatever they paid and need only return whatever portion of the goods or property they still have. In most states, the minor isn’t liable for damage to the item while it was in their possession. After reaching 18, a former minor can ratify the contract, either explicitly or by continuing to use what they received, which makes it fully binding going forward. Contracts for necessities like food, shelter, clothing, and basic medical care are the main exception: minors remain liable for the reasonable value of necessities they’ve received, even after disaffirming.
Agents and Apparent Authority
When someone accepts a contract on behalf of a business or another person, the question is whether they had authority to do so. Actual authority means the principal explicitly or implicitly authorized the agent to act. Apparent authority exists when the principal’s conduct leads a reasonable third party to believe the agent has the power to bind the principal, even if the principal never actually granted it. A common example: a company gives someone the title of “purchasing manager,” and a vendor reasonably assumes that person can commit to supply contracts. Even if the company privately told the manager not to sign deals over $10,000, a vendor who didn’t know about that limit can enforce the contract.
Reliance When an Offer Is Withdrawn
Sometimes a person relies heavily on an offer, quitting a job, turning down other opportunities, or spending money in preparation, only to have the offer pulled before they formally accept. Promissory estoppel may provide a remedy even though no contract was formed. If the offeror should have reasonably expected their promise to induce action, and the offeree relied on it to their detriment, a court may enforce the promise to prevent injustice. The elements typically require a clear promise, reasonable reliance, actual detriment, and circumstances where enforcement is the only way to avoid unfairness.
Promissory estoppel is not a substitute for a real contract, and courts apply it cautiously. It is a safety net for situations where someone’s reliance on a promise was reasonable and the withdrawal caused genuine harm.