B2B SaaS MVP in 12 weeks: line-by-line budget with a French team

The verdict in three sentences

A sellable B2B SaaS MVP delivered in 12 weeks by a Paris agency costs between EUR 45,000 and 90,000 excluding VAT in 2026, depending on the number of user roles, the integrations and the security level your first customers demand. More than half of the budget (around 55%) goes into development, but discovery and acceptance testing are what decide whether the product sells in its first quarter. With a pre-seed round of EUR 300,000 to 800,000, the MVP should stay between 10 and 20% of the capital raised, and if you incorporate in France, Bpifrance's Bourse French Tech can fund up to EUR 30,000.

Where the money goes: breakdown by phase

The split below matches an MVP built around a single value path (for example: a customer signs up, imports data, gets a dashboard and pays a subscription). Anything outside that path moves to V2.

What pushes a project from EUR 45,000 to 90,000: a second user role with its own screens (manager, client admin), enterprise SSO, an ERP or CRM integration, a full multi-tenant model and a security audit requested by enterprise buyers. Each of these adds roughly EUR 5,000 to 15,000.

Paris day rates in 2026, day by day

In 2026 a Paris agency charges between EUR 600 and 850 per day excluding VAT depending on the profile. Here are two typical teams: one for a lean MVP, one for an MVP aimed at enterprise customers.

Two things to watch. First, a quote showing fewer than 30 development days for a B2B SaaS with built-in billing almost always hides a vague scope. Second, require the code, designs and cloud accounts to be in your company's name from week 1: investors will check IP ownership during due diligence. For a founder working remotely with a French team, add a weekly 45-minute demo in English and a shared backlog; Paris is on CET, one hour ahead of London.

Funding the MVP: Bpifrance and other levers

The prudent rule: never start development on the mere promise of a grant. Sign the scoping phase, file the Bpifrance application in parallel and time the development kick-off to the decision.

Mini case study

Claire, founder of a B2B HR startup in Paris, raised EUR 500,000. Her MVP (two roles, Stripe billing, export to the HRIS) is quoted at EUR 68,000 excluding VAT, or 13.6% of the round. The Bourse French Tech covers EUR 30,000 and the innovation tax credit refunds 20% of EUR 40,000 of eligible spend, i.e. EUR 8,000. Net cost: EUR 30,000. Three months after launch, 12 customers pay EUR 400 per month, or EUR 4,800 of monthly recurring revenue: the net cost of the MVP is covered by just over 6 months of revenue.

FAQ

Can a B2B SaaS MVP really ship in 12 weeks?

Yes, provided a single value path is frozen by the end of week 2. Beyond 3 major scope changes, add 2 to 4 weeks and 10 to 20% to the budget.

Fixed price or time and materials for an MVP?

A fixed price protects your budget once discovery is done and the scope is written. Time and materials, at EUR 600 to 850 per day, suits a product that changes every week, but insist on a cap on days.

What does the MVP cost once live?

Plan EUR 200 to 600 per month for hosting and tools, plus corrective maintenance of 10 to 15% of the initial budget per year, i.e. EUR 4,500 to 13,500 for a EUR 45,000 to 90,000 MVP.

Does the Bourse French Tech fund an external agency?

Yes, outsourced development counts as eligible spend. The grant is capped at EUR 30,000 and covers at most 70% of the programme, so the rest must come from equity.

Should I use no-code to move faster?

For a market test under EUR 15,000, yes. For a SaaS sold to companies that will demand a security audit and data export, custom code avoids a EUR 40,000-plus rewrite within 18 months.

Let's scope your project. Send us your value path and an indicative budget: we will return a phase breakdown, a team and a 12-week schedule. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.