Table of Contents
- What is a unilateral contract?
- Can unilateral contracts be breached?
- What is a bilateral contract?
- Can bilateral contracts be breached?
- Key differences between unilateral and bilateral contracts
- When to use unilateral vs bilateral contracts
- Similarities between unilateral and bilateral contracts
- How contract management software can help
- Frequently asked questions about unilateral vs bilateral contracts
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Key takeaways:
Recognize that unilateral contracts require performance to accept the offer, while bilateral contracts create binding obligations for both parties immediately upon agreement through signature or verbal acceptance.
Understand that performance-based unilateral contracts cannot be revoked once someone begins the requested work, but bilateral contracts cannot be revoked after both parties accept without breaching the agreement.
Choose bilateral contracts when you need guaranteed performance and mutual commitments from the start, and select unilateral contracts when you want to incentivize specific results without requiring upfront commitment from either party.
Implement contract lifecycle management software to centralize storage, automate obligation tracking, and monitor performance deadlines across both contract types, preventing the 5% to 9% revenue loss organizations typically experience from poor contract management.
A unilateral contract involves one party making a promise that can only be accepted through action. A bilateral contract involves two or more parties exchanging mutual promises that create obligations for everyone involved.
That distinction matters more than it might seem. It affects enforceability, revocation rights, and what happens when something goes wrong. Most business transactions use bilateral contracts—sales agreements, employment contracts, vendor relationships. Unilateral contracts appear in specific situations: rewards, insurance policies, open requests for services.
Here’s a practical breakdown of both contract types, with real examples so you can identify which type you’re dealing with and understand what your rights and obligations actually are.
What is a unilateral contract?
A unilateral contract is a binding agreement where only one party makes a promise that requires performance to accept. The person making the offer (offeror) commits to do something if the other party (offeree) completes a specific action.
The key characteristic: acceptance happens through performance, not through signing or verbal agreement. The offeree has no obligation to perform the requested action. But once they complete it, the offeror must fulfill their promise. If the offeror fails to deliver after performance, they’ve breached the contract.
Common structure: One party makes an open offer. Anyone who performs the requested action accepts the offer. The contract becomes binding only when performance is complete.
Example of unilateral contract: reward contract
Rewards are one of the most recognizable examples of unilateral contracts in everyday life. The offeror puts out an open request: anyone who meets the specified criteria gets paid, with no prior commitment required from either side.
In a criminal case, for example, the government may offer a reward to anyone who provides useful information about a wanted individual. No specific person is asked to come forward—the obligation only activates when someone actually delivers the information.
The reward can be given to one person or to multiple individuals who meet the specified criteria. You’ll see this same structure in open requests for labor, too.
For instance, a company might advertise that it will pay a certain amount to anyone who completes a specific task. Suppose Person A advertises to pay $500 to someone who can tutor them for an upcoming exam. Person B tutors Person A for the exam. Now, Person A has to pay $500 to Person B as per the advertised request.
Open requests are widespread in our everyday lives. For instance, when your pet gets lost, you first print flyers and distribute them in your neighborhood. Then, you post a “missing reward” advertisement in the newspaper or online where you offer a $150 reward to anyone who finds and returns your pet.
This is a unilateral contract in action, since you are promising to reward the person who finds your pet. You’re the only one offering the reward, and no specific person is obligated to search for your pet.
Insurance contracts
Beyond rewards and open labor requests, insurance policies follow the same unilateral structure. When you buy an insurance policy, the company promises to pay you a certain amount if a certain event occurs. However, if that event doesn’t happen, the company is not obliged to pay you any money.
Can unilateral contracts be breached?
Unilateral contracts can be breached when the offeror fails to fulfill their promise after the offeree completes the requested action. Breach occurs if the offeror doesn’t deliver the promised payment, service, or reward once performance is complete.
Revocation rules determine when an offeror can withdraw their offer. These rules vary by contract type.
Performance-based contracts involve payment for completed work or services. The offeror cannot revoke once the offeree begins performance. If someone starts the work you requested, you must allow them to finish and then pay as promised.
Reward-based contracts offer payment for achieving a specific result, like finding a lost item. The offeror can revoke even after someone starts searching, but only before they achieve the result. Once someone finds your lost pet, you must pay the reward.
Modern contract law protects people who begin performing under a unilateral contract. Once someone starts work based on your promise, you typically cannot revoke without liability.
What is a bilateral contract?
A bilateral contract is a binding agreement where two or more parties exchange mutual promises, with each party obligated to perform specific actions. This exchange of promises creates legal obligations for everyone involved.
Most business contracts are bilateral. When you buy a product, sign an employment agreement, or engage a vendor, you’re entering a bilateral contract. One party promises to deliver goods or services, while the other promises to pay. Even standard non-disclosure agreements (NDAs) fall into this category. Because they are so standardized, NDAs have the lowest rates of counterparty paper at just 2%, according to the 2026 Contracting Benchmark Report.
Key validity requirements include:
An offer from one party
Acceptance by the other party
Exchange of something valuable (consideration)
Legal capacity of all parties to enter the agreement
Unlike unilateral contracts that require performance to accept, bilateral contracts become binding when both parties agree to the terms, typically through signature or verbal acceptance. Take the example of a real estate agreement—a contract is signed between you and the real estate company to purchase a house. Both parties are bound from the moment of signing: the company must provide the property, and you must make the agreed payment.
Can bilateral contracts be breached?
A bilateral contract is breached when one party fails to fulfill their promised obligations. Breach occurs if a party refuses to perform, performs inadequately, or prevents the other party from completing their obligations. These failures don’t just cause operational headaches—they directly impact the bottom line. Organizations typically lose 5% to 9% of their annual revenue due to poor contract management and value leakage, according to The 2025 Legal Operations Field Guide.
Common breach scenarios:
A vendor fails to deliver goods by the agreed deadline
A service provider delivers work that doesn’t meet contract specifications
A buyer refuses to make payment after receiving services
Either party violates confidentiality or non-compete clauses
Breach differs from contract termination. A breach is a failure to perform, which may give the non-breaching party grounds to terminate or seek remedies. Termination ends the contract through proper procedures outlined in the agreement itself.
When breach occurs, the non-breaching party typically has several remedies: demanding performance, seeking monetary damages, or terminating the contract depending on the breach severity—though according to the American Bar Association, 90% of litigated cases settle before trial.
Key differences between unilateral and bilateral contracts
Unilateral and bilateral contracts differ fundamentally in how promises work, when obligations begin, and how acceptance happens. Understanding these distinctions helps you recognize which type you’re dealing with and what that means for enforceability.
Number of parties making promises
Unilateral: Only one party (the offeror) makes a binding promise.
Bilateral: Both parties make mutual promises to each other.
How acceptance works
Unilateral: Acceptance occurs only through completing the requested action. No signature required.
Bilateral: Acceptance happens when both parties agree to the terms, typically through signature or verbal agreement.
When obligations begin
Unilateral: The offeror’s obligation only activates after the offeree completes performance.
Bilateral: Both parties become obligated as soon as they accept the agreement.
Revocation rules
Unilateral: Can generally be revoked before performance begins (with exceptions for performance-based contracts).
Bilateral: Cannot be revoked once both parties accept without breaching the agreement.
Common use cases
Unilateral: Rewards, contests, insurance policies, open requests for services.
Bilateral: Sales agreements, employment contracts, vendor relationships, service agreements.
When to use unilateral vs bilateral contracts
Choose a unilateral contract when you want to incentivize action without creating obligations until someone performs. Use bilateral contracts when you need mutual commitments with clear obligations from the start.
Use unilateral contracts for:
Offering rewards for specific results (finding lost property, reporting security vulnerabilities)
Running contests or promotions where winners receive prizes
Issuing insurance policies where payment occurs only if a specific event happens
Making open requests where you’ll pay anyone who completes a task
Use bilateral contracts for:
Purchasing goods or services from vendors
Hiring employees or contractors
Establishing ongoing business relationships with clear mutual obligations
Any situation requiring both parties to commit before work begins
Here’s the simple way to think about it: if you need guaranteed performance from another party, use a bilateral contract. If you’re willing to pay only for results without requiring commitment upfront, a unilateral contract works well.
Relationships involving ongoing obligations or multiple deliverables benefit from the structure a bilateral contract provides. One-time offers for a specific outcome are a natural fit for unilateral contracts. Most business relationships land in bilateral territory because mutual commitments create certainty and give both parties recourse if something goes sideways.
Similarities between unilateral and bilateral contracts
Unilateral and bilateral contracts share fundamental legal characteristics despite their structural differences. Both create legally binding obligations and require the same essential elements to be valid. Here are the key similarities:
Legal enforceability: Both contract types are legally binding once properly formed. Courts will enforce the terms and provide remedies for breach.
Consideration requirement: Both require an exchange of value (consideration). In unilateral contracts, performance serves as consideration. In bilateral contracts, the mutual promises serve as consideration. Learn more about the essential elements that make any contract valid.
Contract formation elements: Both need offer, acceptance, consideration, and legal capacity to be valid. The timing and method of acceptance differs, but the core requirements remain the same.
Breach consequences: Both provide legal remedies when one party fails to perform. The non-breaching party can seek damages or specific performance.
Written vs. oral validity: Both can be valid whether written or oral, though written contracts are easier to enforce and some types must be in writing under the statute of frauds.
The main structural difference—one-way versus mutual promises—affects how and when the contract becomes binding, but doesn’t change these fundamental legal protections.
How contract management software can help
Contract lifecycle management (CLM) software helps you manage both unilateral and bilateral contracts more effectively by centralizing storage, automating tracking, and monitoring obligations across all your agreements. ACC’s 2024 CLO Survey found that 45% of CLOs plan to invest in technology to help their teams work more effectively. That investment is already paying off for many teams. The benchmark report found that as organizations adopt better contract automation, average days to execute became 5% faster and overall legal involvement fell by 6%.
CLM benefits for unilateral contracts:
Store reward offers, insurance policies, and contest terms in a searchable repository
Track when performance occurs and obligations activate
Automate payment triggers when someone completes the requested action
Monitor revocation windows and performance deadlines
CLM benefits for bilateral contracts:
Organize vendor agreements, employment contracts, and purchase orders
Set reminders for important dates, renewals, and performance milestones
Track mutual obligations and ensure both parties meet commitments
Monitor compliance with terms across your entire contract portfolio
Generate reports showing contract performance and vendor reliability
This is particularly useful for managing bilateral agreements like purchase orders, as well as unilateral agreements like warranties and licenses. Learn how to choose the right tool for you, or request a demo today to see how Ironclad handles both contract types across your entire portfolio.
Frequently asked questions about unilateral vs bilateral contracts
A unilateral promise involves only one party making a commitment (the offeror), while a bilateral promise involves both parties making mutual commitments to each other. The key distinction is that unilateral promises require performance to accept, while bilateral promises create obligations upon mutual agreement.
It depends on the contract type. Performance-based unilateral contracts cannot be revoked once someone begins performing the requested work. Reward-based contracts can typically be revoked before someone achieves the result, but not after completion.
Employment contracts are bilateral because both parties make mutual promises—the employer promises to pay compensation and provide work conditions—while the employee promises to perform specific duties. Both parties have obligations from the start of employment.
Ironclad is not a law firm, and this post does not constitute or contain legal advice. To evaluate the accuracy, sufficiency, or reliability of the ideas and guidance reflected here, or the applicability of these materials to your business, you should consult with a licensed attorney. Use of and access to any of the resources contained within Ironclad’s site do not create an attorney-client relationship between the user and Ironclad.
