August 5, 2025
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by Tanuja Bahirat / August 5, 2025
Deals and agreements can take countless forms.
I’ll pay you ten dollars to mow my lawn. I’ll pay you $500,000 to build me a house.
The specific terms and conditions can take a contract in many different directions. However, when the final agreement is made official, the written or oral contract will fall into a specific category.
As you maneuver your contract management strategy for your business, picking out any types you might encounter is crucial to maximizing contract performance, preparedness, organization, and compliance.
But let’s begin with the basics.
A contract is a legally binding agreement between two or more parties that creates obligations enforceable by law. It requires offer, acceptance, consideration, and mutual intent to be valid. Contracts define rights and duties, ensuring clarity and legal protection in personal, commercial, or governmental transactions.
At its core, a contract is an agreement between two or more entities that’s legally enforceable. It’s the business world’s way of saying, “Here’s the deal, and here’s what happens if we don’t follow through.”
A contract serves two purposes: it clarifies the terms of an agreement, and it ensures that legal sanctions will be imposed in the event of non-compliance. A contract needs to possess the following elements to be legally binding:
Without a formal contract comprising all its basic contract elements, it will be difficult (if not impossible) to demonstrate to the law that your agreement existed or your rights were breached.
As a result, signing a contract is critical. But, selecting the right type of contract is also an essential step in making things work. Therefore, let's go over the most prevalent contract types in business.
The type of contract being used in an agreement can refer to the document's structure, details of compensation, requirements to be legally enforceable, or the associated risks. The contracts listed below are not all comparable to one another and can’t all be used interchangeably.
As promised, here is a complete list of every type of contract you could ever encounter.
Fixed-price contracts, also known as lump sum contracts, are used in situations where the payment doesn’t depend on the resources used or time expended. With fixed-price contracts, sellers will estimate the total allowable costs of labor and materials and perform the action specified by the contract regardless of the actual cost. Because of this, the fixed price presented in the contract usually includes some wiggle room in case unexpected costs occur.
The seller assumes a certain amount of risk using a fixed-price contract, so some will decide to present a range of prices instead of one dollar.
These types of contracts typically include benefits for early termination (meaning the duties were fulfilled) and penalties for missing deadlines. This common practice ensures that the agreement, performance of an action, or whatever the contract’s subject matter, is timely.
When entering a deal that uses a fixed-price contract, be prepared for the contract creation and approval process to take longer than usual. To ensure they account for all time and resources accurately, sellers will be extra careful in determining the price.
Fixed-price contracts are most commonly used for construction contracts. Contractors will decide to use a fixed-price contract because the simplicity can result in buyers paying a higher price upfront to avoid the hassle of tallying up the actual cost. However, that initial estimate can be hard to reach accurately.
A cost-reimbursement contract determines the final total cost when the project is completed or at another predetermined date within the contract’s time frame. Before the project is started, the contractor will create an estimated cost to give the buyer an idea of the budget. They will then provide payment for the incurred costs to the extent described in the contract.
Setting this expectation with cost-reimbursement contracts is to establish a ceiling price that the contractor shouldn’t exceed without the buyer's approval. At the same time, if that ceiling is reached, the contractor can stop work.
Also used for construction projects, a cost-plus contract is a type of cost-reimbursement contract for situations where the buyer agrees to pay the actual cost of the entire project, including labor, materials, and any unexpected expenses.
The word “plus” refers to the fee that covers the contractor’s profits and overhead. In these agreements, the buyer agrees to pay that extra amount and expects the contractor to deliver on their promise.
There are four types of cost-plus contracts, and each one describes how the contractor is reimbursed to earn a profit:
When using a cost-plus contract, the buyer can usually see the entire list of expenses to know what they’re paying for. They will also typically include a maximum price to know the most expensive-case scenario.
Contractors will use cost-plus contracts if the parties don’t have much wiggle room in the budget or if the entire project's cost can’t be appropriately estimated beforehand. Some of these cost-plus contracts might limit the amount of reimbursement, so if the contractor makes an error or acts negligently, the buyer won’t have to pay for their mistakes.
Contractors will decide to use cost-plus contracts because they can make changes throughout the project, and the buyer gets the exact value they paid for. However, it can be frustrating to have the final price up in the air, and getting that number requires extensive attention to detail.
A time and materials contract is like a cost-plus contract, but a little more straightforward. In these deals, the buyer pays the contractor for the time spent to complete the project and the materials used in the process.
Time and materials contracts are also used in situations where it’s not possible to estimate the size of the project or if the requirements for completion are expected to change.
As a buyer, your money will be put toward the material costs and the rate you pay the workers for their time. At the start of the process, you will likely have to come to a mutual agreement on the price of materials, including a markup rate and hourly rates for labor.
Time and material contracts require logging everything happening on the work site, most notably the hours and materials used. Paying close attention to those details will help the contractor and buyer develop the most accurate estimate of the total cost.
Contractors will use time and materials contracts because it simplifies the negotiation process and it’s easy to adjust if the requirements of the project change. A downside is that tracking time and managing materials is tedious work.
With a unit price contract, the total price is based on the individual units that comprise the entire project. When using this type of contract, the contractor will present the buyer with specific prices for each segment of the overall project, and then they will agree to pay them for the number of units needed to complete it.
The word “unit” in these contracts can refer to time, materials, or a combination of both. While the parties can estimate or make guesses, the actual number of units typically can’t be specified at the beginning of the project.
Say you are making a deal with someone to repave your driveway. It’s hard to tell exactly how much cement you’ll need, but the contractor says it costs $1,000 for each truckload of supplies and associated labor. So to redo your entire driveway, you must agree to pay $1,000 per unit. And if it took three units to complete the entire project, you would have to pay the contractor $3,000.
Unit price agreements make for easy-to-understand contracts, but on the side of the contractor, it can be easy for buyers to compare prices with their competitors and cause them to lose some business.
A bilateral contract is one in which both parties exchange promises to perform a particular action. The promise of one party acts as the consideration for the promise of the other and vice versa.
With bilateral contracts, both parties assume the role of obligor and obligee, meaning they have contractual duties to perform and expect something of value.
Bilateral contracts are most commonly used in sales deals, where one party promises to deliver a solution, and the other promises to pay for it. There is a reciprocal relationship here as the obligation to pay for a solution is correlated with the obligation to deliver the solution. If the buyer doesn’t pay or the seller doesn’t deliver, a breach of contract has occurred.
The key element of bilateral contracts is exchanging something of value for another item of value, known as consideration. If only one party offers something of value, this is a unilateral contract.
Unilateral contracts are agreements where a party promises to pay another after they have performed a specified act. These types of contracts are most often used when the offeror has an open request that someone can respond to, fulfill the act, and then receive the payment.
Unilateral contracts are legally binding, but legal issues usually don’t come up until the offeree claims they are eligible for money tied to specific actions they’ve performed and the offeror refuses to pay the offered amount. Courts will decide whether or not the contract was breached depending on how clear the contract terms were and if the offeree can prove they are eligible for payment based on the facts in the agreement.
Examples of situations where unilateral contracts are used include open requests where anyone can respond to a request, and in the case of insurance policies. In those contracts, the insurer promises to pay if something occurs that was included in the term of the contract. So essentially, the insurance company pays the client if they are covered for the situation they encountered.
An implied contract is an agreement based on the involved parties' actions. Implied contracts are not written down and might not even be spoken. The agreement ensures the parties take the designated action to kickstart the contracts.
An example of an implied contract is a warranty on a product. Once you buy a product, a warranty goes into effect that it should work as expected and presented. This contract is implied because it went into effect when someone took a particular action (buying a product), which might not have been written down anywhere.
There are two different types of implied contracts:
An express contract is a category of contracts entirely. In these types of agreements, the exchange of promises includes both parties agreeing to be bound by the terms of the contract orally, in writing, or a combination of both.
Express contracts are often known to be the opposite of an implied contract, which, as a refresher, starts an agreement based on the actions of the parties involved. With express contracts, all terms, conditions, and details of the agreement are expressed (get it?) by writing them down, saying them out loud, or both.
Comparing two types of contracts often means that the parties involved in the agreement can decide which one to use. This is not the case for express and implied contracts. The nature of the agreement determines that for you.
A simple contract is made orally or in writing that requires consideration to be valid. Again, consideration is the exchange of one thing for another and can be anything of value, including time, money, or an item.
Simple contracts are the opposite of contracts under seal, which do not require any consideration and have the seal of the signer included, meaning they have to be in writing. These contracts are officially executed once signed, sealed, and delivered.
While simple contracts require consideration, they don’t have to be express contracts to be legally binding. The agreement is a simple contract that can be implied as well.
An unconscionable contract refers to an agreement that is so obviously one-sided and unfair to one of the parties involved that it can’t be enforceable by law. The court will likely deem it void if a lawsuit regarding an unconscionable contract is filed. No damages are paid, but the parties are relieved of their contractual obligations.
There are a few things that make a contract unconscionable:
If one or multiple events occur when making an agreement, the contract is null and void, and neither party is responsible for their end of the deal.
An adhesion contract, also known as a standard form contract, is sort of a “take it or leave it” situation. In these agreements, one party typically has more bargaining power than the other. When the offeror presents the contract, the offeree has little to no power to negotiate the terms and conditions included. This is contrasted with situations where the offeree can return a counteroffer to the original offeror in hopes of starting negotiations and reaching an agreement they both find suitable.
This lack of negotiation isn’t done with bad intentions. In the case of adhesion contracts, the offeror is typically someone who offers the same standard terms and conditions to all of their offerees. Every contract is identical.
For example, if you were buying insurance, the agent would draw up the contract as they do with every other client, and you would either accept or deny the terms. It’s not likely you’ll be able to negotiate a new contract that you prefer more.
Adhesion contracts must be presented as take it or leave it to be enforceable. Because if one party holds more bargaining power in any other situation, that could be seen as an unconscionable contract. It’s easy for that line to be blurred, causing adhesion contracts to be scrutinized often.
Aleatory contracts explain agreements where parties don’t have to perform their designated action until a triggering event occurs. Essentially, aleatory contracts state that if something happens, then action is taken.
Again, this type of contract is typically used in insurance policies. For example, your provider doesn’t have to pay you until something happens, like a fire that causes damage to your property.
The events that demand action described in an aleatory contract can’t be controlled by either party. Risk assessment is vital in creating aleatory contracts so both parties know the likelihood of that event occurring.
Handling contracts can be tough, especially for contract managers and legal teams dealing with different types. Manually handling them takes up a lot of time and carries the risk of mistakes and non-compliance.
But there's a fix: contract management software. Used in various industries like Marketing, IT, Software, and Finance, this software does the hard work by automating tasks, making processes simpler, and cutting down on the risks of manual work.
G2 data shows that more than half (54.7%) of the people reviewing contract management tools are from small businesses, revealing that it's a cost-effective choice for them. Another 30.1% are from mid-sized companies, and 15.2% are from bigger enterprises. So, for contract managers and legal teams, using this software not only solves the challenges of manual work but also fits well with the needs of businesses, especially smaller ones.
Here's a quick comparison table to help you understand the types of contracts better.
| Contract type | Payment structure | Legal distribution risk | Complexity level | Common use cases |
| Fixed-Price | Lump sum for entire project | Seller assumes cost overruns | Medium | Big-ticket builds, renovations |
| Cost-Reimbursement | Actual costs reimbursed + cap | Buyer bears cost variability | High | R&D, government work |
| Cost-Plus | Actual costs + agreed fee | Shared | High | Custom builds, evolving scope |
| Time and Materials | Hourly/daily rate + materials | Shared | Low–Medium | Consulting, repairs |
| Unit Price | Per unit (time/material combo) | Shared | Low | Roadwork, phased builds |
| Bilateral | Both promise to perform | Shared | Medium | Sales, service delivery |
| Unilateral | Payment after act completed | Offeror bears risk | Low | Rewards, insurance claims |
Different types of contracts serve different purposes. You will need to take a call on what fits your purpose the most. Below are a few aspects you can consider before creating and signing a contract.
Not all contracts fit every business situation. Some work brilliantly when budgets and deliverables are crystal clear, while others shine when flexibility or unknowns are part of the deal. Here’s how to think about when to use each, and when to steer clear.
Best for: Projects with a clearly defined scope, predictable costs, and strict deadlines. Example: A website redesign with a fixed number of pages, or a home renovation with detailed plans and no expected surprises.
Why they work: Fixed-price contracts give buyers cost certainty—what you sign for is what you pay. Contractors often like them too because they can build in incentives for efficiency and keep any leftover margin if they come in under budget.
When to avoid: If your project is still evolving, or if market volatility makes materials unpredictable, fixed-price contracts can backfire. Contractors may inflate initial estimates to cover risks, and buyers may end up paying a “risk premium.”
Best for: Complex projects where costs can’t be predicted upfront. Example: R&D initiatives, software prototypes, or government-funded research where final outcomes are uncertain.
Why they work: They allow contractors to start work without nailing down exact costs, which encourages innovation and exploration. Buyers can adjust as new requirements emerge.
When to avoid: If budget discipline is critical. Since costs are reimbursed, overruns can spiral, and the buyer bears more financial risk. Strong oversight is essential.
Best for: Projects needing high customization or continuous collaboration. Example: Large-scale construction, product development requiring frequent adjustments, or any project where “quality over cost” is the priority.
Why they work: Buyers get visibility into actual costs, while contractors are fairly compensated for overhead and profit. Cost-plus structures also encourage transparency and flexibility as needs evolve.
When to avoid: If trust or transparency is lacking. Without robust cost-tracking, buyers may feel nickel-and-dimed. For fast-moving, budget-sensitive projects, the lack of a firm cap can create friction.
Best for: Open-ended projects with uncertain scope and flexible deliverables. Example: Hiring a developer to build features for an app where requirements will likely shift, or bringing in consultants for ongoing process improvements.
Why they work: They’re easy to draft, straightforward to understand, and flexible enough to adapt as requirements change. Buyers only pay for what gets done.
When to avoid: If scope creep is a real threat. Contractors may have little incentive to be efficient, and costs can balloon unless both parties log hours and materials carefully.
Best for: Projects that can be broken into measurable units of work but where total quantities are unknown at the outset. Example: Roadwork paid by the cubic yard of asphalt, or a construction job priced per truckload of concrete.
Why they work: They simplify bidding, make costs transparent, and give buyers flexibility to scale up or down as needed.
When to avoid: If the units themselves aren’t clearly defined or if quality varies significantly between units. Contractors also risk losing business if buyers can easily shop around for cheaper unit prices from competitors.
Contracts have moved far beyond paper signatures and filing cabinets. Today’s modern agreements lean heavily on technology to deliver speed, security, and flexibility. The most common emerging types include:
Modern contract types don’t replace traditional ones, but they streamline how contracts are created, signed, and enforced, especially in industries where speed and global collaboration are non-negotiable. Reviewers on G2 highlight that AI-powered contract management and review platforms significantly speed up contract turnaround, enhance risk detection, and improve compliance visibility.
Want to compare tools? See G2’s roundup of the best contract management software to find solutions backed by user reviews.
Think of contract management as a loop, not a checklist:
Compliance Pointers:
Have more questions? Find the answers below.
The most common types of business contracts are sales agreements, service contracts, employment agreements, nondisclosure agreements, lease agreements, and partnership agreements. These contracts define rights, obligations, and terms between parties, ensuring legal protection and clear expectations in business transactions.
The main difference between cost-plus and time-and-materials contracts is that cost-plus contracts reimburse actual costs plus a set profit margin, while time-and-materials contracts charge for hours worked and materials used at agreed-upon rates. Cost-plus shifts more risk to the buyer, while time-and-materials balances risk between both parties.
The main difference in enforcement is that express contracts are enforced based on clearly stated terms agreed by the parties, while implied contracts are enforced based on the conduct, actions, or circumstances showing mutual intent. Courts use written or verbal proof for express contracts and inferred evidence for implied contracts.
Use a unit price contract when project quantities are uncertain or likely to change. This contract sets a fixed rate per unit of work, allowing flexible adjustments to total cost as quantities vary. It is common in construction projects where exact measurements are unknown at the start.
Contract management software streamlines the creation, tracking, and storage of contracts. It automates approval workflows, alerts stakeholders to key deadlines, and maintains compliance by storing audit trails. The software reduces administrative errors, improves collaboration, and provides real-time visibility into contract performance and obligations.
A contract is unconscionable when its terms are extremely unfair, favoring one party due to unequal bargaining power. It is unenforceable when it violates the law, lacks essential elements like mutual consent, or is impossible to perform. Courts may void such contracts to protect fairness and legality.
The best type of contract for services is a service agreement, which defines the scope of work, payment terms, deadlines, and performance standards. This contract ensures clarity between provider and client, reduces disputes, and establishes legal protection for both parties during the service period.
The main difference between a simple contract and a formal contract is that a simple contract can be verbal or written and does not require a seal, while a formal contract is written, signed, and often sealed or witnessed. Formal contracts carry stricter legal requirements and higher evidentiary weight.
Choose the right contract type by assessing project scope, budget certainty, risk allocation, and performance requirements. Fixed-price contracts suit well-defined projects with stable costs, while cost-plus or time & materials contracts work better for flexible or uncertain scopes. Match the contract type to risk tolerance and control needs.
Your business might not encounter every one of those contract types, but it’s your responsibility to be prepared for any that might come your way. After reviewing all those examples, familiarize yourself with the contracts your business will likely encounter. An extra layer of preparedness never hurt.
Compliance can take many forms with all the different types of contracts. Look at these seven tips for contract compliance that will keep you in line no matter the circumstances.
This article was originally published in 2020. The content has been updated with new information.
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Tanuja Bahirat is a content marketing specialist at G2. She has over three years of work experience in the content marketing space and has previously worked with the ed-tech sector. She specializes in the IT security persona, writing on topics such as DDoS protection, DNS security, and IoT security solutions to provide meaningful information to readers. Outside work, she can be found cafe hopping or watching football. Connect with her on LinkedIn.
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