When you hire a software development company, choosing the right team is only part of the decision.
You also need to decide how the project will be priced and managed.
Two common software development models are Fixed Price and Time and Materials.
With a Fixed Price model, you agree on a defined project scope, estimated timeline, and price before development begins.
With a Time and Materials model, you pay for the actual time and resources used to develop your product.
At first, Fixed Price may sound like the safer option because the budget appears more predictable. However, software projects often change as businesses review designs, test early versions, receive customer feedback, or discover new requirements.
That is where Time and Materials can provide more flexibility.
Neither model fits every project.
The right choice depends on how clearly you can define your requirements, how likely they are to change, how much flexibility you need, and how you want to control your development budget.
This guide explains Fixed Price vs Time and Materials, how both models work, their advantages and limitations, and what businesses should understand before signing a software development agreement.
What Is the Fixed Price Development Model?
A Fixed Price model means the client and development company agree on a defined scope of work and price before development starts.
The company first reviews the requirements.
After that, it estimates how much work the project will require and provides a proposal.
For example, imagine your business needs an appointment booking application.
The agreed first version might include:
- Customer registration and login
- Service listings
- Available appointment slots
- Booking and cancellation
- Online payments
- Email notifications
- Booking history
- Admin dashboard
- Android and iOS applications
- Testing and launch assistance
After reviewing these requirements, the development company might provide a fixed quotation for the complete agreed scope.
If you accept it, the company develops those features according to the contract.
What does “fixed” actually mean?
Fixed Price does not normally mean that you can request unlimited features without changing the price.
The agreed amount applies to the agreed scope.
Suppose online payments are included in the original requirements. Later, you decide to add monthly subscriptions, discount codes, customer wallets, and automatic refunds.
Those additions may fall outside the original scope.
The development company can review the new requirements and provide an additional estimate.
Therefore, Fixed Price works best when both sides clearly understand what needs to be built.
What Is the Time and Materials Model?
Time and Materials, often shortened to T&M, uses a different approach.
Instead of agreeing on one price for the entire final scope, you pay for the actual development resources used during the project.
Development time usually represents the main cost.
Depending on the agreement, other project-related expenses may also apply.
For example, the development company might charge for the hours worked by developers, designers, testers, or other specialists.
The client and development team can then adjust priorities as the project progresses.
A simple example
Imagine you are building a new SaaS platform.
You know the main problem you want to solve, but you are not completely sure which features customers will use most.
The team builds the first part of the product.
After testing it with users, you discover that customers need a simpler onboarding process.
Instead of continuing with the original feature order, you decide to improve onboarding first.
With a Time and Materials model, the team can usually change priorities more easily because you pay for the work performed rather than purchasing one completely fixed scope.
Fixed Price vs Time and Materials: What Is the Main Difference?
The biggest difference is how the two models handle scope, cost, and change.
Fixed Price starts with a more clearly defined scope.
The development company estimates that scope and agrees on a price.
Time and Materials allows the scope to evolve more easily.
The team works on agreed priorities, while the client pays for the resources used.
This means Fixed Price usually provides more initial cost predictability for a stable scope.
Meanwhile, Time and Materials usually provides more flexibility when requirements are expected to change.
However, both models still require planning, communication, budgeting, and project management.
1. How Clear Are Your Requirements?
Start by considering how much you already know about the project.
Can you clearly explain the users, features, workflows, platforms, integrations, and business rules?
If yes, estimating the complete project may be easier.
Clear requirements
Suppose you need a business customer portal.
You already know that customers should log in, view invoices, download documents, update account details, and contact support.
Your company also has approved designs and documented business rules.
A Fixed Price model may be easier to structure because the expected work is relatively clear.
Evolving requirements
Now imagine you are developing an entirely new digital product.
You understand the main idea, but you expect to test features with users during development.
Some features may change.
Others may disappear completely.
New priorities may emerge.
In this situation, Time and Materials can provide more room to adapt.
2. Budget Predictability
Businesses often choose Fixed Price because they want to know the project cost before development begins.
For a defined scope, this can provide useful budget predictability.
Suppose the agreed project costs €25,000.
Your business can plan around that amount for the work described in the agreement.
However, you should still check the exclusions.
Hosting, third-party subscriptions, payment-provider fees, app store accounts, content creation, or future maintenance may not be included.
Additionally, new requirements can increase the overall cost.
Budgeting with Time and Materials
Time and Materials has more cost variability because the total depends on the work performed.
However, this does not mean your budget has to remain uncontrolled.
You can establish financial limits.
For example, you could agree on a monthly development budget.
The team then prioritizes work within that amount.
Alternatively, you can approve development in stages.
After each stage, you review progress and decide how much additional work to authorize.
Therefore, budget control is possible under both models. The method simply differs.
3. Flexibility During Development
Fixed Price depends heavily on the agreed scope.
Small clarifications may be easy to manage.
However, significant new requirements can require formal changes.
For example, imagine your original project includes customer registration using an email address and password.
Halfway through development, you decide to add Google, Apple, and Microsoft sign-in.
The team may need to estimate this additional work.
Flexibility with Time and Materials
T&M generally makes changing priorities easier.
Suppose the development backlog contains ten planned features.
After reviewing the first release, you decide that Feature 8 is now more important than Feature 4.
The team can change the order.
Likewise, you might remove a planned feature and spend that development time improving something customers value more.
This flexibility can be useful for products that evolve through testing and feedback.
4. Planning Before Development
Fixed Price usually requires more detailed planning before development starts.
The development company needs enough information to estimate the work.
That may include user roles, workflows, features, platforms, integrations, design requirements, backend functionality, and testing expectations.
Unclear requirements make accurate fixed pricing difficult.
Does T&M require less planning?
It can require less detailed long-term specification, but it still requires good planning.
The development team needs to understand the product goals.
Individual features should also have enough detail before developers start building them.
The difference is that you do not necessarily need to define every future feature before the first development phase begins.
You can refine later requirements as the project progresses.
5. How Are New Requirements Handled?
New requirements can appear in almost any software project.
Imagine you are building an e-commerce application.
Your original scope includes standard online payments.
During development, your business decides to introduce a customer loyalty system.
With Fixed Price
The team first checks whether the loyalty system belongs to the agreed scope.
If not, the company may prepare a change request.
That request can explain the new work, additional price, and possible effect on the delivery schedule.
You decide whether to approve it.
With Time and Materials
The team can estimate the loyalty feature and add it to the backlog.
You then decide its priority.
Developers spend the required time building and testing it, and the work becomes part of your T&M billing.
Both models can support new requirements.
However, T&M normally requires fewer contractual scope adjustments when priorities change frequently.
6. Project Timeline
A Fixed Price project often begins with an estimated timeline for the agreed scope.
For example, a company might divide development into design, development, testing, client review, and deployment stages.
This can make scheduling easier.
However, the timeline still depends on several factors.
Late client feedback can cause delays.
New requirements may extend development.
Third-party integrations can also create unexpected issues.
Therefore, a fixed price should not be confused with an unconditional guaranteed launch date unless the contract specifically defines it that way.
Timeline under T&M
Time and Materials projects often use shorter planning cycles.
The team may plan work weekly, monthly, or in development sprints.
Important features receive higher priority.
As a result, businesses can focus on getting the most valuable functionality completed first.
This can be especially useful when the complete product roadmap is expected to evolve.
7. Client Involvement
Both models require client participation.
However, the type of involvement may differ.
With Fixed Price, the client usually spends more effort defining and approving requirements before development.
During the project, the business may review designs, approve milestones, answer questions, and test completed functionality.
With T&M, ongoing prioritization becomes especially important.
The client may regularly review progress and decide what the team should work on next.
Therefore, businesses choosing T&M should have someone available to make product decisions.
Without clear priorities, flexibility can turn into unnecessary development work.
8. Transparency and Progress Tracking
A good development company should provide project visibility regardless of the pricing model.
For Fixed Price, you should be able to track progress against the agreed scope and milestones.
For T&M, visibility into both progress and resource usage becomes particularly important.
You should understand what the team worked on and how much development effort it required.
For example, regular reports might explain which features were completed, which tasks remain in progress, and how much of the current budget has been used.
Transparency helps businesses manage costs without needing to monitor developers constantly.
9. Project Risk
Both models involve risk, but the risk is distributed differently.
With Fixed Price, the development company commits to an agreed price for a defined scope according to the contract.
Therefore, accurate estimation becomes important for the provider.
If the requirements are unclear, the company may include additional contingency in its estimate or define more assumptions and exclusions.
Risk under T&M
With T&M, the client carries more uncertainty around the final cost.
If the product requires additional work, the total cost can increase.
However, the client also has more freedom to change direction.
If a planned feature no longer provides enough value, you can remove it from the backlog.
Therefore, the decision is not simply about which model has less risk.
Instead, consider which type of uncertainty your business can manage more effectively.
10. Quality and Testing
Neither pricing model automatically creates better software.
A Fixed Price team should not reduce testing simply to protect its budget.
Likewise, a T&M team should not spend unnecessary hours on avoidable work.
Before signing an agreement, ask how testing works.
Find out whether the project includes functional testing, device or browser testing, integration testing, and other relevant quality checks.
Also clarify how bug fixes are handled.
For example, if an agreed feature does not work correctly, understand whether fixing it is part of the original work.
Clear definitions help avoid billing disagreements later.
When Does Fixed Price Make Sense?
Fixed Price can make sense when your requirements are clear and stable.
For example, your business may already have detailed requirements and approved designs.
You know exactly which platforms, features, and integrations you need.
The project also has limited uncertainty.
Common situations may include:
- Business websites
- Clearly defined internal tools
- Small customer portals
- Defined mobile app versions
- Specific software integrations
- Projects with approved specifications
It can also suit organizations that need a defined project budget before receiving internal approval.
However, Fixed Price becomes harder to manage when the scope changes frequently.
When Does Time and Materials Make Sense?
T&M can be useful when requirements are expected to evolve.
For example, you may be creating a new SaaS product and want to change features based on early customer feedback.
It can also work well for ongoing product development.
After launch, software may require new features, improvements, compatibility updates, and maintenance.
You may not know all these requirements months in advance.
Time and Materials allows the business to prioritize work as new needs appear.
Other suitable situations can include complex projects, long-term development, research-heavy features, product modernization, and projects with significant technical uncertainty.
Fixed Price vs T&M for an MVP
An MVP, or Minimum Viable Product, can use either model.
The right choice depends on how clearly the MVP has been defined.
Imagine you already completed product discovery.
You have approved designs, documented workflows, a clear feature list, and known integrations.
A development company may be able to estimate that MVP as a fixed project.
Now consider a different startup.
It has a promising idea but needs to experiment with several workflows before deciding what users actually need.
In that situation, T&M may provide useful flexibility.
Therefore, do not select a pricing model simply because your project is called an MVP.
Consider how much uncertainty still exists.
Fixed Price vs T&M for Long-Term Development
Long-term software development usually involves changing priorities.
Customers request improvements.
Business processes change.
Operating systems and external services evolve.
New competitors may introduce features that affect your roadmap.
As a result, defining every future requirement in one fixed scope can be difficult.
T&M can provide flexibility for ongoing product development.
However, businesses can still use Fixed Price for individual, well-defined pieces of work.
For example, you could use T&M for general product development while agreeing on a fixed scope for a specific migration or integration.
Can Fixed Price and T&M Be Combined?
Yes.
You do not necessarily need to use one model for the entire relationship.
A hybrid approach can work well for some projects.
For example, the development company could complete a clearly defined discovery and design phase for a fixed price.
After both sides understand the product better, development could continue under T&M.
Another business might use Fixed Price for its first application release.
After launch, it could move to T&M for maintenance and continuous feature development.
The important point is to define where one pricing model ends and the other begins.
How to Control a Time and Materials Budget
One of the biggest concerns about T&M is budget control.
Fortunately, businesses can create clear spending rules.
Set a budget limit
You might establish a monthly or development-phase budget.
For example, your business could authorize up to €10,000 of development during a particular month.
If the team expects to exceed that amount, it should request approval first.
Prioritize features
Not every feature has equal value.
Keep the most important functionality near the top of the development backlog.
This helps ensure that your budget goes toward the highest-priority work first.
Review estimates
Before starting a large feature, ask for an estimate.
It may not be an exact guarantee, but it can help you understand the expected effort.
Review progress regularly
Regular demonstrations and progress reports allow you to see what your budget is producing.
If priorities need to change, you can adjust them before the team spends more time on lower-value work.
How to Manage a Fixed-Price Project
Fixed Price also requires active management.
Start with a clear scope.
Make sure important features, user roles, integrations, platforms, and deliverables appear in the project documentation.
Next, understand the assumptions.
For example, the company may expect your team to provide content, API access, or design feedback within a specific period.
You should also understand the change-request process.
If you request additional functionality, the company should explain its effect on price and timeline before starting the work.
Finally, review milestones and test the product throughout development rather than waiting until the final delivery.
Example: Building a Customer Booking Platform
Imagine a business wants a platform where customers can book home services.
The system needs customer accounts, service listings, available time slots, online payments, notifications, booking history, and an admin dashboard.
Scenario A: Fixed Price
The company already understands its complete booking process.
The features are documented.
Payment requirements are known, and the business has approved the user experience.
The development team can estimate the defined scope and provide a fixed quotation.
If the client later requests a loyalty program, that feature can be estimated separately.
Scenario B: Time and Materials
Another company is testing a completely new service model.
It is unsure whether customers should select individual providers or allow the system to assign them automatically.
Pricing rules may also change after initial testing.
In addition, the company plans to collect feedback from early customers before finalizing later features.
T&M gives the team more freedom to adjust the product as those decisions become clearer.
Scenario C: Hybrid Model
The business could first complete product discovery and UI/UX design for a fixed amount.
After validating the requirements, it could choose Fixed Price for clearly defined development or continue with T&M if significant uncertainty remains.
Questions to Ask Before Choosing Fixed Price or T&M
Before signing an agreement, discuss these questions with the development company:
- How clearly can we define the complete project today?
- Which requirements could change during development?
- What exactly does the Fixed Price include?
- What is excluded from the quotation?
- How will change requests work?
- What happens if a feature requires more work than expected?
- How are T&M hours recorded?
- Do different specialists have different rates?
- Are meetings and project management billable?
- Can we set a monthly or milestone spending limit?
- How frequently will we receive progress and budget reports?
- How are testing and bug fixes handled?
- Which third-party costs are separate?
- What happens if we pause development?
- How will future maintenance and features be priced?
These questions can reveal important differences between proposals that initially look similar.
Common Mistakes to Avoid
Assuming Fixed Price means unlimited work
A fixed amount normally applies to a defined scope.
New requirements can still require additional payment.
Starting a Fixed Price project with unclear requirements
If requirements remain unclear, both sides may interpret the scope differently.
Spend enough time defining the project first.
Treating T&M as an unlimited budget
T&M should still include estimates, priorities, progress tracking, and spending controls.
Choosing only by the lowest price
A cheaper proposal may include fewer features, less testing, or fewer services.
Compare equivalent scopes before comparing prices.
Ignoring third-party expenses
Development pricing may not include hosting, paid APIs, SMS services, payment fees, app store accounts, or other external costs.
Ignoring post-launch development
Think beyond the first release.
Your product may require maintenance, updates, and additional features after launch.
Frequently Asked Questions
What is the difference between Fixed Price and Time and Materials?
Fixed Price uses an agreed price for a defined project scope. Time and Materials charges according to the development resources used during the project.
Is Fixed Price cheaper than T&M?
Not necessarily. The final cost depends on project complexity, requirements, changes, team experience, and the agreement. The models mainly differ in how cost and scope are managed.
Is Time and Materials the same as hourly development?
They are closely related, although contract structures can differ. Development time usually forms a major part of T&M billing, while the agreement may also cover other approved project resources or expenses.
Can the cost of a Fixed Price project increase?
Yes. If you request functionality outside the agreed scope, the development company may provide an additional estimate.
How can I control spending with T&M?
Set budgets, prioritize features, review estimates, track resource usage, and hold regular progress reviews. You can also require approval before spending exceeds an agreed limit.
Which model is suitable for a startup?
It depends on how clearly the startup has defined its product. A well-defined first release may fit Fixed Price, while an experimental product with changing requirements may benefit from T&M flexibility.
Can I use Fixed Price for an MVP?
Yes. If the MVP has clear features, workflows, platforms, and deliverables, it can be suitable for a Fixed Price agreement.
Can both pricing models be used in one project?
Yes. For example, discovery and design could use Fixed Price, while evolving development and maintenance could use T&M.
Conclusion
The choice between Fixed Price and Time and Materials depends mainly on how much certainty exists around your software project.
Fixed Price provides greater initial budget predictability when the requirements and deliverables are clearly defined. However, frequent changes can require additional estimates and change requests.
Time and Materials provides more flexibility when requirements are expected to evolve. At the same time, businesses need clear priorities, regular progress reviews, and budget controls.
You can also combine both models.
For example, a business may use Fixed Price for a clearly defined first version and T&M for future improvements.
Before choosing, consider your project’s requirements, uncertainty, expected changes, budget restrictions, and long-term development plans.
Most importantly, read the agreement carefully. Make sure you understand what the price includes, how changes are handled, how costs are tracked, and what happens when the project moves beyond its original plan.
A pricing model should support the way your project needs to work rather than force your project into a structure that does not fit.
