SaaS MVP development contract: fixed price vs time and materials (2026)

The verdict in three sentences

For a SaaS MVP funded by a 400,000 EUR round, a fixed price reassures on budget but triggers change orders as soon as the product evolves, while time and materials follows the pace of learning at the cost of tight steering. The best compromise in 2026 is often a fixed price per short phase with a 20/30/30/20% schedule tied to testable deliverables. Whatever the model, three clauses are non-negotiable: contractual acceptance, code ownership and an exit clause with handover of all access.

Fixed price or time and materials: what each model really costs

A fixed price always includes a risk premium: the vendor prices uncertainty. On an MVP where 30% of features change after the first user tests, you pay that premium twice, once in the price and once in change orders. Time and materials avoids this double cost but requires a product owner available at least 2 days a week on the startup side.

A 4-milestone schedule that protects both sides

Simple rule: no payment without a demonstrable deliverable. A milestone called "50% of development" with no demo means nothing. Tie every payment to a user journey you can test yourself.

Clauses to write in black and white

Contractual acceptance. Define an acceptance period (10 to 15 business days), three defect levels (blocking, major, minor) and the validation rule: the report is signed when no blocking defect remains and at most 5 major ones have a fix plan.

Intellectual property. The assignment of economic rights over the specific code must be explicit, with duration, territory and media, otherwise it is not valid under French law and is risky under most others. Open source components and the vendor's internal libraries are covered by a usage licence.

Exit clause. In case of termination, the vendor hands over within 10 days the full Git repository, cloud access, documented environment variables and a deployment README. Provide for 30 days' notice and pro rata payment for work done, not flat penalties.

Reversibility. Require the code to live in a repository owned by the startup from day one. It is the most effective protection and it costs nothing.

Mini case study

Léa, founder of a scheduling SaaS for veterinary clinics in Paris, raised 400,000 EUR. She compares three offers for her MVP.

• Fixed price: 92,000 EUR excl. VAT, with about 18% likely change orders, so around 108,500 EUR.
• Time and materials: 140 estimated days at 620 EUR, so 86,800 EUR, capped at 100,000 EUR.
• Fixed price per phase: 3 phases of 28,000 EUR, so 84,000 EUR, with reprioritisation between phases.

She picks the phased model, saves about 24,000 EUR compared with the fixed price plus change orders, and keeps 6% of her round for acquiring the first 30 clinics.

FAQ

Is time and materials more expensive than fixed price?

Not necessarily. With a moving scope, time and materials often costs 10 to 20% less because it carries no risk premium. It becomes more expensive if nobody steers the backlog every week.

What deposit is reasonable at signature?

Between 20 and 30%. Above 30%, the client's leverage disappears too early, especially with a vendor you have never worked with.

How long does a SaaS MVP take?

In 2026, a serious MVP takes 10 to 16 weeks with a team of 2 to 4 people. Under 8 weeks usually means a very narrow scope or no-code.

What if the vendor disappears?

With a Git repository, cloud accounts and deployment docs in your name, a new vendor can take over in 2 to 4 weeks. Without them, expect a partial rewrite of 30 to 50%.

Do I need a lawyer to review the contract?

Yes for any contract above 50,000 EUR. A specialist review costs 800 to 2,500 EUR excl. VAT, less than 3% of the MVP budget.

Let's scope your project. Share your backlog and fundraising calendar, and we will propose a phase breakdown, a payment schedule and an indicative budget. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.