Study guide
2.3 Acceptance & the Mailbox Rule
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1 Introduction & FYLSE Examination Guide
1.1 FYLSE Exam Structure, Passing Standard & Administration 1.2 Study Method, Pacing & MBE-Style Technique
2 Contracts: Mutual Assent, Capacity & Contract Formation
2.1 The Offer & Objective Theory of Assent 2.2 Termination & Irrevocability of Offers 2.3 Acceptance & the Mailbox Rule 2.4 Mirror Image Rule & UCC 2-207 Battle of the Forms 2.5 Mistake in Contract Formation 2.6 Fraud, Duress, Undue Influence & Illegality 2.7 Capacity to Contract
3 Contracts: Consideration, Estoppel & Implied Obligations
3.1 Consideration & the Bargained-For Exchange 3.2 Past & Moral Consideration, Pre-Existing Duty & Modification 3.3 Promissory Estoppel & Detrimental Reliance 3.4 Implied-in-Fact Contracts & Quasi-Contract 3.5 Implied Covenant of Good Faith, Fair Dealing & Indefinite Terms
4 Contracts: Third-Party Beneficiaries, Assignment & Delegation
4.1 Third-Party Beneficiary Contracts 4.2 Assignment of Rights 4.3 Delegation of Duties
5 Contracts: Statute of Frauds, Parol Evidence & Interpretation
5.1 Statute of Frauds: Contracts Within the Statute 5.2 Satisfying the Statute: Writing, Signature & Exceptions 5.3 The Parol Evidence Rule 5.4 Contract Interpretation & Canons of Construction
6 Contracts: Performance, Conditions, UCC Warranties & Breach
6.1 Conditions: Express, Constructive & Excuse 6.2 Substantial Performance vs. Perfect Tender 6.3 Cure, Rejection, Revocation & Installment Contracts 6.4 UCC Article 2 Warranties & Risk of Loss 6.5 Anticipatory Repudiation & Insecurity
7 Contracts: Remedies, Discharge & Changed Circumstances
7.1 Expectation Damages & Their Limitations 7.2 Reliance, Restitution & Liquidated Damages 7.3 Specific Performance & Injunctive Relief 7.4 UCC Article 2 Buyer's and Seller's Remedies 7.5 Impossibility, Impracticability & Frustration of Purpose 7.6 Discharge by Agreement: Rescission, Novation & Accord and Satisfaction
8 Criminal Law: Principles of Criminal Liability & Mens Rea
8.1 Actus Reus, Voluntary Acts & Omissions 8.2 Criminal Causation & Intervening Causes 8.3 Common Law & Model Penal Code Mens Rea 8.4 Mistake of Fact, Mistake of Law & Concurrence
9 Criminal Law: Inchoate Offenses & Accomplice Liability
9.1 Criminal Attempt & Impossibility 9.2 Solicitation & the Merger Doctrine 9.3 Conspiracy & Merger Doctrine 9.4 Accomplice Liability: Actus Reus & Mens Rea 9.5 Scope of Accomplice Liability, Withdrawal & Parties to Crime
10 Criminal Law: Homicide & Crimes Against the Person
10.1 Common Law Murder & Malice Aforethought 10.2 Degrees of Murder, Premeditation & Deliberation 10.3 The Felony Murder Rule & Its Limitations 10.4 Voluntary & Involuntary Manslaughter 10.5 Non-Homicide Crimes Against the Person
11 Criminal Law: Property Crimes, Theft & Habitation
11.1 Common Law Larceny 11.2 Embezzlement & False Pretenses 11.3 Robbery & Extortion 11.4 Receiving Stolen Property 11.5 Burglary 11.6 Arson
12 Criminal Law: Defenses: Capacity, Justification & Excuse
12.1 Insanity: The Four Legal Tests 12.2 Intoxication, Diminished Capacity & Infancy 12.3 Self-Defense & Defense of Others 12.4 Defense of Property, Habitation & Law Enforcement Privileges 12.5 Duress & Necessity 12.6 Entrapment & Mistake as an Excuse
13 Torts: Intentional Torts to Persons & Property
13.1 Intent, Motive & Incapacity in Intentional Torts 13.2 Transferred Intent 13.3 Battery & Assault 13.4 False Imprisonment 13.5 Trespass to Land 13.6 Trespass to Chattels & Conversion
14 Torts: Privileges & Defenses to Intentional Torts
14.1 Consent: Express, Implied & Capacity 14.2 Exceeding & Vitiating Consent 14.3 Self-Defense & Defense of Others (Tort) 14.4 Defense of Property & Recapture of Chattels 14.5 Public & Private Necessity 14.6 The Shopkeeper's Privilege
15 Torts: Negligence — Duty of Care & Breach
15.1 Duty of Care & the Foreseeable Plaintiff 15.2 Affirmative Duties to Act & Special Relationships 15.3 Standard of Care: The Reasonable Person & Children 15.4 Professional Negligence, Informed Consent & Negligence Per Se 15.5 Land Possessor Liability & Premises Duties 15.6 Breach of Duty & Res Ipsa Loquitur
16 Torts: Causation, Defenses, Multiple Tortfeasors, Wrongful Death & Damages
16.1 Cause in Fact & Multiple Actors 16.2 Proximate Cause & Intervening Forces 16.3 Contributory, Comparative Negligence & Assumption of Risk 16.4 Joint and Several Liability, Contribution & Indemnity 16.5 Vicarious Liability & Non-Delegable Duties 16.6 Wrongful Death & Survival Actions 16.7 Statute of Limitations & Claim Accrual 16.8 Tort Damages: Compensatory, Nominal, Punitive & Mitigation
17 Torts: Strict Liability & Products Liability
17.1 Strict Liability for Animals 17.2 Abnormally Dangerous Activities & Scope of Risk 17.3 Strict Products Liability & Defect Categories 17.4 Products Liability Under Negligence, Warranty & Misrepresentation 17.5 Defenses to Products Liability
18 Torts: Emotional Distress, Defamation, Privacy & Economic Torts
18.1 Intentional Infliction of Emotional Distress 18.2 Negligent Infliction of Emotional Distress 18.3 Common Law Defamation: Elements, Libel & Slander 18.4 Constitutional Limits, Privileges & Defenses to Defamation 18.5 Invasion of Privacy 18.6 Nuisance & Economic Torts
2.3 Acceptance & the Mailbox Rule
Key Takeaways Explain This Topic AI
Acceptance requires a manifestation of assent on the offer's terms by a person who knows of the offer and is the one to whom it was directed.
Under the mailbox rule, acceptance is effective on dispatch while revocations, rejections, and counteroffers are effective on receipt.
The mailbox rule does not apply to option contracts, where acceptance must actually be received within the option period.
If the offeree dispatches a rejection first and then an acceptance, whichever arrives first controls.
Last updated: September 2026
Acceptance & the Mailbox Rule
Acceptance is the final exercise of power granted by an offer, resulting in the creation of a binding contract. This section examines how acceptance is manifested, the timing rules governing dispatch and receipt under the Mailbox Rule, the strict requirements of the common law Mirror Image Rule, and the commercial realities codified in the UCC § 2-207 Battle of the Forms.
- I. Nature and Mechanics of Acceptance
- Definition of Acceptance
Under Restatement (Second) of Contracts § 50, acceptance is a manifestation of assent to the terms thereof made by the offeree in a manner invited or required by the offer.
Who Holds the Power of Acceptance?
An offer can be accepted only by the person or entity to whom it was directed. The power of acceptance is strictly personal and non-assignable . An offeree cannot transfer the power of acceptance to a third party. (Contrast: Once a binding option contract or final contract is formed, the resulting contractual rights are freely assignable unless restricted by contract or statute).
Modes of Acceptance: Bilateral vs. Unilateral Contracts
Bilateral Contracts : An offer seeking a return promise. Under modern law (Restatement (Second) § 32), unless an offer unambiguously dictates otherwise, an offer is presumed to invite acceptance either by promising to perform or by actual performance .
Unilateral Contracts : An offer expressly requiring acceptance solely through full completion of the requested act. Notice of acceptance is generally not required unless the offeree has reason to know the offeror has no adequate means of learning of the performance with reasonable promptness.
Acceptance under UCC § 2-206 (Sales of Goods)
Under UCC § 2-206(1)(b), an order or offer to buy goods for prompt or current shipment invites acceptance either by a prompt promise to ship or by the prompt or current shipment of conforming or non-conforming goods :
Conforming Goods Shipped : Operates as acceptance, forming a contract.
Non-Conforming Goods Shipped : Operates simultaneously as an acceptance and a breach .
The Accommodation Exception : If the seller ships non-conforming goods and seasonably notifies the buyer that the shipment is offered only as an accommodation to the buyer, the shipment does not operate as an acceptance. Instead, it constitutes a counteroffer , which the buyer is free to accept or reject without breach.
Silence as Acceptance
As a general principle, an offeror cannot unilaterally mandate that the offeree's silence will constitute acceptance ("If I do not hear from you by Friday, we have a contract"). Under Restatement (Second) § 69, silence operates as acceptance in only three narrow circumstances:
The offeree takes the benefit of offered services with reasonable opportunity to reject them and reason to know they were offered with the expectation of compensation;
The offeror has stated or given the offeree reason to understand that assent may be manifested by silence, and the offeree in remaining silent intends to accept;
Because of previous dealings, it is reasonable that the offeree should notify the offeror if they do not intend to accept.
II. The Mailbox Rule ( Adams v. Lindsell )
Contractual communications do not occur instantaneously across distances. The Mailbox Rule establishes default timing rules allocating the risk of transmission delays or lost mail.
The Core Rule: Dispatch vs. Receipt
Acceptance by Mail / Dispatch : An acceptance dispatched by an authorized or reasonable medium is legally effective upon proper dispatch (the moment it is placed in the custody of the US Postal Service or private courier with proper postage and address), regardless of whether it ever reaches the offeror.
All Other Communications Effective on Receipt : Revocations, rejections, counteroffers, and initial offers are legally operative only upon actual receipt by the intended recipient (or delivery to their place of business/residence). ┌─────────────────────────────┬────────────────────────────────────────────────────────┐
- │ Communication Type │ Effective Timing │
- ├─────────────────────────────┼────────────────────────────────────────────────────────┤
- │ Offer │ Effective on RECEIPT │
- │ Revocation by Offeror │ Effective on RECEIPT │
- │ Rejection by Offeree │ Effective on RECEIPT │
- │ Counteroffer by Offeree │ Effective on RECEIPT │
- │ Acceptance by Offeree │ Effective on DISPATCH (Mailbox Rule) │
- └─────────────────────────────┴────────────────────────────────────────────────────────┘
- Four Critical Exceptions to the Mailbox Rule
- 1. Offeror Stipulates Receipt ("Master of the Offer")
The offeror may alter the default rule by explicitly stating in the offer: "Acceptance is effective only upon receipt at my office by 5:00 PM on Friday." In this scenario, the mailbox rule is bypassed; dispatch does not conclude the contract.
2. Option Contracts (Restatement § 63(b))
The Mailbox Rule does not apply to the exercise of an option contract. Acceptance under an existing option contract is effective only upon receipt by the offeror before the option expiration date.
3. Rejection Dispatched First, Followed by Acceptance ("The Race")
If an offeree mails a rejection first and subsequently changes their mind and mails an acceptance, the Mailbox Rule is suspended.
Whichever communication the offeror receives first controls.
If the rejection is received first: The offer is terminated immediately, and the later-arriving acceptance is treated as a counteroffer.
If the acceptance is received first: A binding contract is formed at the moment of receipt.
4. Acceptance Dispatched First, Followed by Rejection
If an offeree mails an acceptance first and later sends a rejection (e.g., via telegram, overnight courier, or phone):
A binding contract was formed at the moment the acceptance was dispatched under the Mailbox Rule.
The subsequent rejection is legally a nullity or an offer to repudiate/rescind.
Detrimental Reliance Estoppel : If the offeror receives the rejection first and materially and detrimentally relies on it (e.g., selling the goods to a third party) before receiving the acceptance, the offeree is equitable estopped from enforcing the contract.