TL;DR: in 2026, a custom business application generally costs €8,000 to €80,000 for a French SME depending on scope; a genuinely usable first version goes into production in 4 to 6 weeks, and a small, well-scoped build starts at €400 (excl. VAT).
"How much, and by when?" are the first two questions any business owner asks before replacing spreadsheets and a stack of SaaS subscriptions with a tool built for their actual process. The honest answer fits in two numbers and one method, laid out below with sourced ranges.
Key takeaways
- In France, an internal management tool bills at €8,000 to €20,000, a business application with workflows at €15,000 to €40,000, and an advanced platform at €30,000 to €80,000, according to the budgeting guide published by the agency KreaRise on July 6, 2026.
- On timelines, the market quotes 1 to 3 months for a simple project and 3 to 9 months for medium complexity (Space-O Technologies, guide updated August 20, 2026); an MVP-first method ships a usable version in 4 to 6 weeks.
- An experienced freelance developer in France charges €400 to €700 per day in 2026; an agency bills up to €1,200 per day, project management and design included.
- Mathieu Haye's public price points: a sprint from €400 (excl. VAT) for a well-defined scope, a full MVP in 4 to 6 weeks on written quote, evolutions through a monthly retainer.
How much does a custom business application cost in 2026?
For a French SME, the budget most often lands between €8,000 and €80,000 in 2026, and where you sit in that range depends first on functional scope, not on technology. The budgeting guide published by the French agency KreaRise on July 6, 2026 (source in French) gives benchmarks by project type, consistent with what independents in the field observe. The table below sums up those ranges.
| Project type | French market range, 2026 | Typical examples |
|---|---|---|
| Internal management tool | €8,000 to €20,000 | Production tracking, planning, reporting |
| Client portal | €10,000 to €25,000 | Case files, documents, online approvals |
| Business app with workflows | €15,000 to €40,000 | Quotes, field jobs and invoicing connected |
| Advanced platform | €30,000 to €80,000 | Multi-account SaaS, marketplace with payments |
Internationally, the orders of magnitude run higher: Space-O Technologies, in its guide updated August 20, 2026, puts an MVP at $15,000 to $70,000 and simple software at $40,000 to $120,000, with hourly rates of $60 to $120 in Western Europe. Those figures usually assume full teams; a well-equipped senior independent comes in well under those amounts on the same scope.
My own public price points are deliberately simple: an automation sprint or a small, well-scoped build starts at €400 (excl. VAT); a full MVP, with user accounts, payment and production deployment, is priced with a written quote before the first day of code; evolutions then run through a monthly retainer. No opaque package: the scope is framed in 30 minutes and the quote is set before work starts.
How long does it take to put the application in production?
Count on 4 to 6 weeks for a genuinely usable first version when the scope is cut down seriously; that is the timeline I work to with an MVP-first method. The market often quotes longer: 1 to 3 months for a simple project, 3 to 9 months for medium complexity, beyond 9 months for large programs, according to Space-O Technologies. KreaRise, for its part, cites 3 to 8 weeks for SME web projects depending on complexity.
The gap between 6 weeks and 6 months is not a gap in seriousness: it comes from the scope of the first delivery. A waterfall project specifies everything upfront and delivers everything at the end; an MVP-first method cuts the scope down to the journey that delivers value (sign-up, main action, payment if needed), puts it in production, then iterates on real usage. The second model reduces both the timeline and the risk: each budget step is decided on usage facts, not on meeting-room assumptions.
What moves the price up or down?
Four factors weigh more than all the others. The number of integrations first: every tool to connect (accounting, telephony, ERP, payments) adds days of work. Then the complexity of the business logic: specific calculation rules, multi-level approvals or multi-organization accounts cost more than simple record management. Compliance requirements: GDPR, hosting in France, access logging. Post-launch support, finally: the French market puts maintenance for an SME application at around €3,000 per year.
The price of a working day matters too. In 2026, the median day rate for a freelance developer in France is €525 according to the TJMetre barometer (source in French); observed ranges go from €400 to €700 for an experienced profile, and an agency bills up to €1,200 per day, project management and design included. At equal scope, the real variable is not the advertised rate but the number of days required: AI tooling has markedly cut that number for developers who built it into their practice, which is what makes a 4-to-6-week MVP realistic for a solo developer.
When custom is not the right choice
Three cases where the right answer is to build nothing. If an off-the-shelf SaaS covers nearly all of your need for a reasonable subscription, take it: custom is not justified for a 5% comfort gain. If your volume is low, a few cases a week and two users, a well-kept spreadsheet or a no-code tool is often enough, and the €15,000 will be better invested elsewhere. And if your current tools are fine but do not talk to each other, an automation that connects them costs a fraction of an application and fixes the actual problem.
Custom becomes rational in the opposite case: you pay for several subscriptions that each do 80% of the wrong job, held together by CSV exports and double data entry, and your real process fits no tool on the market. At that point, an application that encodes your exact logic replaces the subscription stack, removes the double entry and belongs to you: no imposed price increase, no captive data.
How I work, concretely
My method has four steps: a 30-minute scoping call that ends with a scope, a timeline and a written quote; a 4-to-6-week build with a staging URL updated every week; a production deployment with monitoring, backups and handover documentation; then iteration at the pace of real usage, through a monthly retainer if you want a regular rhythm. The default stack combines Next.js, Supabase, Stripe and n8n, and the delivered code belongs to you entirely, Git repository included. It is the method behind the business back offices and the B2B monitoring SaaS I put in production this year, and behind this site's own back office. I build the software your company wishes it had found on the market; the written quote before the first line of code is part of the deal.
The takeaway: the price of a business application is not a mystery, it is a function of scope. Scope small, ship fast, decide the next step on usage facts. The right question for any provider is not "how much does the application cost?" but "what is the smallest version that delivers value, and when is it in production?".
Frequently asked questions
How much does an MVP of a business application cost in 2026?
In France, an MVP of a business application for an SME generally lands between €8,000 and €40,000 depending on scope, according to KreaRise's 2026 budgeting guide. With Mathieu Haye, a tightly scoped sprint starts at €400 (excl. VAT) and a full 4-to-6-week MVP is priced with a written quote before the project starts.
Why do prices vary so much between providers?
Because the day rate and the number of days move together: from €400 to €700 per day for a freelancer to €1,200 per day at an agency, and from 30 days to more than 100 depending on the method. An agency bills a full team, project management, design, development and testing; a senior independent developer covers the same scope alone, with less coordination and AI tooling that cuts the number of days.
How much does maintenance cost for a custom application?
The French market puts maintenance for an SME application at around €3,000 per year: hosting, security updates, small fixes. A monthly retainer additionally covers feature evolutions at the pace of real usage; its amount is set after go-live, based on the rhythm you choose.
Is an application in 4 to 6 weeks really credible?
Yes, on one condition: the scope must be cut down to the essential journey before the first line of code. The 4-to-6-week window covers a main journey, user accounts, payment if needed and a back office; it does not cover 40 pages of specifications. Everything else arrives through iterations, decided on real usage.
Want to know where your project sits in these ranges? List the three tasks that cost you the most data entry or coordination, and check whether an off-the-shelf tool truly covers them. If the answer is no, a 30-minute scoping call is enough to set a scope, a timeline and a quote; the full approach is described on the custom web app page.