The verdict in three sentences
In 2026, a custom web app MVP in Amsterdam costs 18,000-35,000 EUR, and a full application 45,000-90,000 EUR depending on modules and integrations. Cost is driven by the day rate (450-650 EUR at an agency) and by effort in person-days, not by a magic fixed price. Then budget 12-18 % of the initial cost per year in maintenance to keep the app alive and secure.
Where the budget actually goes
A custom app quote reads by value area, not by lines of code. Design and UX weigh more than expected because they prevent building the wrong feature.
| Area | Share of budget | On a 60,000 EUR project |
|---|---|---|
| Scoping & UX design | 15-20 % | 9,000-12,000 EUR |
| Back + front development | 50-55 % | 30,000-33,000 EUR |
| Integrations (payment, API, ERP) | 8-12 % | 5,000-7,000 EUR |
| Testing & QA | 8-12 % | 5,000-7,000 EUR |
| Deployment & go-live | 4-6 % | 2,500-3,500 EUR |
| Project management | 8-10 % | 5,000-6,000 EUR |
Projects that overrun are almost always the ones where scoping was rushed to "move fast."
Sample quote by functional lot
Splitting into lots lets you prioritise and spread the spend. Here is a 2026 order of magnitude for an SME business app.
| Functional lot | Effort (person-days) | Indicative cost |
|---|---|---|
| Authentication & role management | 8-12 | 4,000-7,000 EUR |
| Dashboard & reporting | 12-18 | 6,500-10,000 EUR |
| Core business module (advanced CRUD) | 20-30 | 11,000-18,000 EUR |
| Payment integration (Stripe/Wave/OM) | 6-10 | 3,000-6,000 EUR |
| Email/SMS notifications | 4-6 | 2,000-3,500 EUR |
| Admin panel & exports | 8-12 | 4,000-7,000 EUR |
| QA + deployment | 8-12 | 4,000-7,000 EUR |
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Mini case study
Eric, manager of a trading SME in Amsterdam (22 staff), wants to replace spreadsheets with an order-tracking app. We scope an MVP with 3 lots: internal catalogue, order tracking, dashboard. Estimated effort 48 person-days at 520 EUR = 24,960 EUR, plus 9 % project management ≈ 2,250 EUR, so ~27,200 EUR. Maintenance at 15 %/year is ~4,100 EUR/year. By removing 6 hours of re-keying per week (≈ 1,200 EUR/month of staff time), payback lands in ~19 months.
FAQ
Why do two agencies quote so differently? Because scope and finish level vary: a 40 % gap often comes from different assumptions on integrations and QA. Compare against an identical spec.
Fixed price or time-and-materials? Fixed price secures a budget when scope is clear; T&M (billed at 450-650 EUR/day) fits fast-moving products. Many 2026 projects start fixed-price on the MVP, then move to T&M.
Is custom worth it versus SaaS? Above 20-30 users with specific processes, amortisation often happens in 24-40 months with no recurring licence. Below that, SaaS is faster.
What does maintenance cover? Bug fixes, security updates, version upgrades and small evolutions: budget 12-18 % of initial cost per year, i.e. 3,000-16,000 EUR depending on project size.
Can part of it be financed? Yes, regional digital-transformation grants may co-fund such projects; verify your 2026 eligibility.
Let's scope your project. Tell us the perimeter (modules, integrations, data volume) and an indicative budget, and we will price the MVP and full app separately. 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.
