Fixed price or time and materials: which should you choose?
Choose fixed price when the work can be specified before you sign. Choose time and materials when it cannot. Fixed price moves more delivery risk to the vendor, while time and materials leaves scope and cost risk with you. Many software projects combine them: a fixed-price launch, then a monthly retainer.
A disclosure: HALO Studio sells fixed-scope projects and monthly retainers, so weigh our view accordingly. The agency guides cited here also sell software services.
The two models compared
| Fixed price | Time and materials | |
|---|---|---|
| You pay for | An agreed result | Hours actually worked |
| If the estimate was too low | The vendor usually absorbs it, within the agreed scope | You pay for the extra time |
| If you change direction | A change order, which can add cost and time | The team can switch quickly, and the budget moves |
| Best for | Defined MVPs, replatforms, stable integrations | Research, post-launch iteration, maintenance, staff augmentation |
| Main risk | A vague scope leads to disputes or a price that includes a large buffer | Costs grow without strong direction from you |
| You need to provide | Clear requirements and acceptance criteria up front | Ongoing priorities, review and budget control |
The risk split and best-fit cases follow Bolder Apps' 2026 comparison.
Is one model cheaper?
Not reliably. The fixed-price figure includes the vendor's risk. Time and materials can start lower, then grow. Framesixty cites one analysis saying that time-and-materials projects commonly exceed their estimate by 30% to 60% without strong client direction. That figure is an agency's estimate, not a controlled study. Compare the likely total, including change orders, instead of the opening number.
The common hybrid
A frequent recommendation is to use a fixed price for the defined launch, then a time-and-materials retainer for iteration after launch. If the scope is unclear, a short paid discovery stage can produce a specification that makes a fixed quote possible. Bolder Apps calls the fixed launch and retainer hybrid the 2026 default for most custom app projects under $300,000.
Clauses to insist on, whichever you choose
- Written acceptance criteria. Define what "done" means and how it will be tested.
- Code and IP ownership. State when ownership transfers to you, including design files.
- A change process. Say who approves changes and how they are priced.
- An exit clause. Require handover of code, credentials and documentation if you part ways.
- A cap for time and materials. A not-to-exceed figure limits how far the budget can drift.
Have a lawyer review the contract. This article is general guidance, not legal advice.
Four questions to decide
- Could you write the acceptance criteria today? If yes, lean towards fixed price.
- Do you have someone who can set priorities every week? If not, time and materials is riskier.
- Is your budget a hard limit? Choose fixed price or a capped contract.
- Are you still testing what to build? Start with a short discovery stage or prototype.
How HALO Studio works
Our process follows the hybrid. After a 3–5 day discovery stage, Sprints and Builds run at a fixed price with weekly demos, and nothing changes without your sign-off. Orbit is a monthly retainer for what comes after launch. See how much an MVP costs for budget context.