The verdict in three sentences
A credible B2B SaaS MVP is built in London in 2026 for 45,000-100,000 EUR (roughly 55,000-120,000 USD) in 3 to 5 months, provided you hold to a single core feature. The stack that saves time without debt: Next.js + Supabase + Stripe, with auth and billing ready out of the box. Only raise after real traction — an MRR of 5-10k EUR beats ten decks of projections.
What an MVP actually covers in 2026
An MVP is not a stripped-down V1: it is the smallest product that proves someone will pay. Scope differences explain 80 % of the gap between two quotes.
| Element | MVP (3-5 months) | Full V1 (8-12 months) |
|---|---|---|
| Business features | 1 core + 2 satellites | 5-8 modules |
| Authentication | Email + Google (Supabase) | SSO, SAML, fine roles |
| Billing | Basic Stripe Checkout | Pro-rata billing, dunning |
| Roles | Admin / user | Multi-tenant, permissions |
| Reporting | 3-4 KPIs | Configurable dashboards |
| Indicative budget | 45,000-100,000 EUR | 150,000-280,000 EUR |
The winning move: ship in 4 months with the core, then reinvest revenue into the modules customers actually demand.
Cost per module and the 2026 day rate
In London, a senior full-stack developer day rate sits between 550 and 800 EUR in 2026; a tech lead reaches 850-1,000 EUR. Here are the typical MVP line items.
| Module | Effort (days) | Indicative cost |
|---|---|---|
| Setup, CI/CD, design system | 8-12 | 5,500-9,000 EUR |
| Auth + account management | 6-10 | 4,000-7,000 EUR |
| Core business feature | 25-40 | 16,000-28,000 EUR |
| Stripe billing + webhooks | 8-12 | 5,500-9,000 EUR |
| Dashboard + reporting | 10-15 | 6,500-11,000 EUR |
| QA, deployment, docs | 8-12 | 5,500-9,000 EUR |
Add a 10-15 % buffer for the unexpected and 1,600-3,800 EUR/month of maintenance after launch to fix and iterate.
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Mini case study
Thomas, founder of an HR startup in London, wants to validate an annual-review tracking tool. MVP scope: core feature (review cycle), auth, Stripe billing, 4 KPIs. Quote: 68,000 EUR over 4 months (average day rate 650 EUR).
He launches at 4.5 months, signs 22 customers at 49 EUR/month within three months — an MRR of 1,078 EUR. Reinvesting, he hits 8,200 EUR MRR by month 10 — the threshold he set for raising. Result: he negotiates his seed on numbers, not promises, giving up 5-8 fewer points of dilution.
FAQ
How long for a B2B SaaS MVP? Plan 3 to 5 months in 2026 for a disciplined scope (one core feature). Beyond 6 months it is often a disguised V1 that inflates the budget by 40-60 %.
Which stack in 2026? Next.js + Supabase + Stripe covers auth, database, billing and hosting with a time-to-market cut of 30-40 % versus a fully custom stack.
When should I raise? After traction: an MRR of 5-10k EUR and churn under 5 %/month value your startup higher and reduce dilution.
In-house team or agency? For a first MVP, an agency ships in 3-5 months with no hiring cost (35,000-45,000 EUR of payroll per dev/year avoided); in-housing makes sense after product-market fit.
What is the minimum credible budget? Below 45,000 EUR, you risk a throwaway MVP to rewrite; the healthy 2026 range is 45,000-100,000 EUR.
Let's scope your project. Tell us your core feature, indicative budget and target timeline, and we'll define the most cost-effective MVP scope. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
