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If you need talent to meet project demands, explore our Fixed Price Model for flexible and scalable team support.
A fixed price contract sets the scope, price and timeline before development starts, and the vendor commits to deliver that scope for that price. You know the total cost from day one. Any change to the agreed scope goes through a formal change request, which can add cost and time.
A time and materials contract bills you for the actual hours the team works, at agreed rates, plus agreed costs such as tools or licenses. Scope can change as you learn, and timesheets show where the time goes. Most time and material software development engagements work this way, often with a monthly budget cap, because the requirements keep evolving.
Fixed vs time and material pricing differs most in budget certainty, flexibility and who carries the risk. Fixed price gives you a known cost but locks the scope, while time and material lets the scope move but leaves the final cost open. The table below compares both on seven points that usually decide the choice.
Each model trades something for something else. Fixed price trades flexibility for budget certainty, and time and material trades budget certainty for flexibility. Neither is safer in general. Which one is safer for you depends on how stable your requirements are and how much time you can spend steering the project.
Fixed price: pros
Fixed price: cons
Time and material: pros
Time and material: cons
Software development time estimation is the same skill in both models, but it carries different weight. In fixed price, the estimate becomes the price, so it must be thorough and include room for risk. In time and material, the estimate is a forecast you refine each sprint, so it guides decisions rather than locking them.
In fixed price, the vendor breaks the specification into small tasks, estimates each one, and adds allowance for risks such as unclear requirements or third-party integrations. Many teams use three-point estimates (optimistic, most likely and pessimistic) for the riskier tasks. If the estimate is wrong, someone pays: the vendor through lost margin, or you through change requests and disputes about what was "in scope".
In time and material, teams usually estimate in story points or hours for the next sprint or two, and give a broader range for the full release. As the team learns the codebase and the product settles, the forecast gets more accurate. You can see the burn rate early and adjust scope if the numbers drift.
Early estimates are uncertain in any model. The less defined the work, the wider the realistic range, which is exactly why fixed price needs a clear scope to be fair to both sides.
Whichever model you choose, the contract should spell out how scope, changes, payments, quality and ownership work. In fixed price, the scope document, acceptance criteria and change request process carry the most weight. In time and material, rates, reporting, budget controls and notice terms matter most, because the scope is expected to move.
In a fixed price contract, agree:
In a time and materials contract, agree:
In both, agree written IP assignment to your company, and how the project is handed over if it ends early.
Choose fixed price when the scope is clear, stable and documented, and budget certainty matters most. Choose time and material when requirements will change, you want to start quickly, and you can stay involved. If you can't yet describe the work in detail, that's usually a sign time and material, or a paid discovery first, fits better.
Choose fixed price if...
Choose time and material if...
For a wider look at all the options, including staff augmentation, see our guide on how to choose an engagement model.
Example: Consider a company that needs a booking website with a fixed set of pages, a payment integration and a launch date set by a marketing campaign. The scope is clear and won't change, so fixed price fits. Now consider a startup building its first product, unsure which features users will value most. Its scope will shift every few weeks, so time and material fits better.
The most common hybrid is fixed price for a clearly bounded first stage, such as a discovery phase or an MVP, then time and material for ongoing development. You get cost certainty while the risk is highest, and flexibility once the product is live and learning from users. Many vendors offer this as standard.
A paid discovery phase on a fixed price is a natural starting point: the deliverables are clear, and its output is exactly the specification a fixed price build or a reliable time and material forecast needs. From there, you can build the MVP on a fixed price if the scope is tight, then move to time and material for the features that follow.
The reverse also works: start on time and material to explore a complex integration or legacy system, then move the parts that become well understood onto a fixed price. Other mixes include time and material with a monthly cap, and fixed price milestones inside a longer time and material engagement. You can compare these and other engagement models side by side before deciding.
Example: Consider a logistics company with a clear MVP: shipment tracking, notifications and a simple admin panel. It agrees a fixed price for the MVP so the launch budget is certain. After launch, customer feedback brings a steady stream of new requests, so it moves to time and material and sets priorities sprint by sprint.
AI coding assistants and automated testing speed up routine work, but they don't remove the need to choose a pricing model carefully. Fixed price still needs a clear scope, and features built on AI models are hard to scope upfront because results depend on real data and tuning. That usually pushes AI-heavy work toward time and material.
A practical approach is to split the work: fix the price of predictable parts such as the interface, APIs and admin screens, and run experimental AI features, model tuning and data work on time and material. Ask your vendor how AI tools affect their estimates, and who pays for any AI tool licenses or usage.
The most common mistake is choosing a model by price alone instead of by how stable the scope is. A fixed price that looks cheaper can grow through change requests, and time and material without oversight can drift. Match the model to how well you know the work, then put the right controls in place.
CodeFulcrum offers fixed price, time and material and staff augmentation, so the model can match the project rather than the other way around. Founded in 2019, CodeFulcrum has a 4.8 rating on Clutch. We recommend a model after understanding your scope, timeline and how involved you want to be, and we'll explain the trade-offs openly.
For new products, we often start with a fixed price discovery or MVP and move to time and material once the product is live. Whichever model you choose, you get regular progress updates and clear terms for how changes are handled.
If you need extra talent to meet project demands, explore our Staff Augmentation Model for flexible and scalable team support.
The quickest way to choose is to talk through your scope, timeline and budget with someone who works with both models every day. Tell us about your project and we'll recommend fixed price, time and material or a mix, with the reasons behind it. Talk to our team, and we'll be honest if the cheaper option is the better fit.
Fixed price is not always cheaper than time and material. It includes a margin for risk, while time and material bills actual hours, so stable scope decides which costs less.
A time and materials contract bills the client for actual hours worked at agreed rates, plus agreed costs. Scope can change, and the final cost depends on the work done.
Yes, you can switch from fixed price to time and material, usually after a defined stage such as an MVP. Agree how and when the switch works in the original contract.
Time and material is usually better for agile development, because priorities change every sprint. Fixed price can still work for agile teams when it covers a tightly defined release or milestone.
You control costs in a time and material project with a budget cap, regular forecasts, sprint reviews and clear priorities, so the team always works on the most valuable items first.
When requirements change in a fixed price project, the change goes through a change request. The vendor estimates the extra work, and you approve the added cost and time before it starts.
What Is a Fixed Price Contract?
What Is a Time and Materials Contract?
Fixed vs Time and Material Pricing: Comparison Table
How Software Development Time Estimation Works in Each Model
When to Choose Fixed Price or Time and Material
Hybrid Options: Fixed Price First, Then Time and Material
How AI Is Changing Both Pricing Models
Common Mistakes When Choosing a Pricing Model
