Unilateral Real Estate Contracts (Rules)

In U.S. contract law, a unilateral real-estate offer generally becomes accepted when the offeree completes the performance the offer requires, not merely by preparing to act. Beginning invited performance may create temporary protection against revocation under Restatement (Second) of Contracts § 45. But state law, the offer’s terms, notice rules, and land-writing requirements control.

A common question, stated here as an illustrative example, is: “If I started doing what the property owner asked, can they still take back the offer?” The answer depends on what the offer asked you to do, what you did and when, and which state’s law applies.

I use four questions to organize the analysis: What kind of offer is this? What counts as acceptance? Could the offer be revoked? Does the agreement meet the state’s writing rules? This guide explains the general U.S. common-law framework. It is not a substitute for checking the governing state’s statutes, court decisions, and contract language.

What makes a real-estate offer unilateral?

A unilateral offer asks for an act in exchange for a promise. Acceptance generally happens through the requested performance, rather than through a return promise. In real-estate matters, this differs from many ordinary purchase agreements, where buyer and seller exchange promises to complete the sale.

For example, an owner might offer to pay a broker a fee if the broker produces a buyer who meets stated conditions. The broker’s performance, not a promise to try, may be what the offer invites. The exact wording matters: an offer that asks for a promise can create a different kind of agreement.

A bilateral contract is an agreement in which each side makes a promise. Many signed purchase-and-sale agreements work this way: the buyer promises to pay, and the seller promises to convey the property, subject to the contract’s terms. Calling an agreement “unilateral” does not make it so. Read what each party must do.

An option contract is different again. It gives someone the right to accept a separate offer within a stated period, while limiting the offeror’s ability to withdraw that offer during that period. An option is not automatically created just because an offer invites performance. It generally needs consideration or another legally recognized basis for enforcement, and state rules can differ.

Key point: Classify the transaction from its terms and conduct, not its label. A land-sale offer, a unilateral reward-style offer, and an option may raise different issues.

When does performance accept the offer?

Acceptance by performance generally occurs when the offeree completes the act the offer requests. Starting work, making plans, or spending money to get ready is usually not the same as finishing the required act. The offer’s wording and the governing state’s law determine what performance counts and when acceptance is complete.

The Restatement (Second) of Contracts § 50 describes acceptance by performance as acceptance through the act the offer invites or requires. If an owner offers a stated payment for securing a buyer who signs a qualifying purchase agreement by a deadline, for example, merely advertising the property may not meet that condition. The signed agreement may be the required performance.

Do not assume every step must be finished in one particular way. The offer may set conditions, define a deadline, or require that a result occur. Ask:

• What exact act does the offer require?
• Does the offer require a particular result, such as a signed agreement?
• Is there a deadline or another condition?
• Does the text allow partial performance or another method of acceptance?

Starting performance and temporary protection

Section 45 addresses offers that invite acceptance through performance. In general, when the offeree tenders or begins the invited performance, an option contract may arise that temporarily prevents revocation. The offeror’s duty to complete the exchange remains conditional on the offeree finishing or tendering the required performance.

This rule can protect an offeree who has begun the requested act from having the offer withdrawn mid-performance. But it is not a guarantee that every effort to act makes an offer irrevocable. Preparatory steps alone, such as arranging financing or drafting documents, generally do not count as beginning the invited performance. State courts may interpret the boundary differently.

Key point: Identify the act the offer invites, then separate preparation, commencement, and completion. Those stages can have different legal effects.

Can the offeror revoke during performance?

Revocation is the withdrawal of an offer before it has been accepted. Under general common-law principles, an offer may often be revoked before acceptance unless a rule or agreement makes it temporarily or otherwise irrevocable. For an offer inviting performance, § 45 may limit revocation after the offeree begins that performance.

The timing is central. Compare the time of any attempted revocation with the start and completion of the invited performance. Also check whether the offer states a fixed period, whether a separate option exists, and whether the offeree followed any required method of acceptance. A deadline alone does not always create an enforceable option; the legal basis for keeping the offer open matters.

Notice of acceptance

Under Restatement § 54, an offeree who accepts by performance generally does not need to notify the offeror unless the offer asks for notice or the offeror has no adequate way to learn that performance occurred. If notice is required, the offer’s terms and applicable law matter. A failure to give required notice on time can affect whether the offeror has a duty to perform.

For instance, an owner may be able to observe that a specified act has been completed. In another situation, completion may occur without the owner knowing. Read the notice clause closely and keep records of when notice was sent, how it was delivered, and whether the contract requires receipt by a particular date.

Key point: Do not rely on a general rule about notice when the offer sets its own instructions. Follow the stated method and deadline, and preserve proof.

What writing is needed for a real-estate agreement?

The Statute of Frauds is a state law that requires certain agreements to be evidenced by a writing to be enforceable. Agreements involving the sale of land, and often options to buy land, may fall within these laws. The required signatures, terms, and permitted exceptions vary by jurisdiction.

A writing may need to identify the parties and property and state key terms, such as price or the basis for setting it. These are common issues to check, not a universal checklist. Some states may require additional terms or apply different standards. Whether documents together satisfy the rule can also depend on local law and the facts.

A writing problem is separate from the question of acceptance. An offeree might show that performance met an offer’s conditions but still face a dispute over whether the agreement meets the state’s writing requirement. Conversely, a signed document does not by itself prove that the offer was accepted on time or that a required condition was met.

Some jurisdictions recognize exceptions, including forms of part performance or reliance, but their scope and requirements vary. Do not assume that paying money, taking possession, or making improvements will cure a missing writing. Check the state’s statutes and relevant decisions before relying on an exception.

Key point: Verify the writing rule for the specific state and transaction. Do not treat a general common-law rule as a substitute for that check.

How to analyze a disputed offer

A useful analysis follows the timeline and keeps separate questions separate. I start by collecting the offer, any related option, messages, signed documents, and records of performance. Then I identify the jurisdiction and apply its statutes and cases to the actual terms and events.

Illustrative transaction scenarios

These are hypothetical fact patterns, not reported cases or predictions about any particular state’s law.

• Preparation before revocation: An owner offers a fee if a broker produces a buyer who signs a qualifying contract. Before contacting buyers, the broker pays for an advertisement. The owner then withdraws the offer. The advertising cost may be preparation, not commencement of the invited performance. Check the offer and state law before drawing a conclusion.
• Performance begins before revocation: The broker begins contacting buyers in response to the offer, and the owner attempts to withdraw it before a qualifying buyer signs. Section 45 may be relevant because invited performance began. Whether the conduct qualifies and what protection follows depend on the facts and governing law.
• Performance completed, notice disputed: A qualifying agreement is signed before the offer deadline, but the broker does not tell the owner until later. Section 54 and the offer’s notice terms become important, especially if the owner could not otherwise learn of completion.
• Option with unclear paperwork: A buyer pays a stated amount for time to decide whether to purchase, but the option document lacks a property description or signature. Even if the parties intended an option, local writing and consideration rules may affect enforceability.

The examples show why one fact rarely resolves the dispute. A useful file includes dated copies of the offer and any amendments, proof of performance, payment records, notices, and delivery confirmations. A lawyer in the state where the property is located can assess how local law applies.

Conclusion and frequently asked questions

The general framework separates formation, acceptance, revocation, notice, and writing requirements. A performance-based offer may be protected once invited performance begins under Restatement § 45, but that principle is not a universal state rule and does not replace the offer’s terms. Confirm the jurisdiction, map the timeline, and check the applicable land-writing law.

Does a unilateral offer become binding when I begin performing?
Not necessarily. Beginning invited performance may create temporary protection against revocation under Restatement § 45, but acceptance and enforceability depend on the offer, facts, and state law.

Is preparing to perform the same as beginning performance?
Generally, no. Planning or arranging resources is usually preparatory. Courts examine whether the offeree began the act the offer actually invited.

When is a unilateral offer accepted?
Generally, when the offeree completes the performance required by the offer. The offer may define conditions, deadlines, or other steps that affect acceptance.

Can a real-estate offer be revoked before performance is complete?
Possibly. Section 45 may create temporary protection after invited performance begins, but the rule’s application and any separate option depend on the facts and governing law.

Does an option to purchase need consideration?
Often an option needs consideration or another recognized legal basis to be enforceable. The rules can vary by state, so review local law and the option document.

Must acceptance by performance be reported to the offeror?
Not always. Under Restatement § 54, notice is generally unnecessary unless requested or needed because the offeror has no adequate way to learn of performance. Contract terms and state law may alter the result.

Does a real-estate agreement have to be in writing?
Many land-sale agreements and options are subject to a state Statute of Frauds. The required writing, signatures, and terms vary by jurisdiction.

Can part performance make an unwritten land agreement enforceable?
Some states recognize exceptions, but their tests differ. Do not assume that payment, possession, or improvements automatically satisfy the writing requirement.

What should I check first in a dispute?
Identify the state and transaction type, read the offer and any option, build a dated timeline, and verify the local writing and notice rules.

(This article was written by one of our staff writers, James Holloway. Visit our Meet the Team page.)