You asked for three quotes on custom software. One comes back at €18,000, another at €95,000, and the third refuses to give a number without a "€8,000 scoping phase." No surprise: the price of custom software depends on so many variables that no generic answer holds up. Yet realistic ranges do exist, and I am going to lay them out here with no sugarcoating.
I have been commissioning business software for over ten years, first with French contractors, then with senior Vietnamese teams. My finding: costs can vary by a factor of three depending on the model you choose, for the exact same functional scope.
- 📊 Realistic range: from €5,000 (simple tool) to €250,000 (full SaaS) in 2026.
- ⚠️ Hidden costs: maintenance, training, and integrations inflate the bill by 30 to 50%.
- 🌍 Vietnam option: a senior offshore team cuts the budget in half, with quality maintained.
- ⚡ AI and productivity: AI-augmented devs ship 40% faster than two years ago.
What custom software really costs in 2026
The price of custom software falls between €5,000 and €250,000 depending on complexity. That is not a lazy range: it reflects the reality of three very different project categories.
What budget should you plan for based on project complexity?
A simple internal tool (process automation, small dashboard, business add-on) costs between €5,000 and €15,000. According to the magram.fr guide, this bracket covers design, basic testing, and deployment on lightweight infrastructure.
Once you move to a business application (custom CRM, tailored ERP, inventory management with scheduling), the bill climbs to between €15,000 and €75,000. According to ctdev.fr, it is workflow customization, third-party integrations, and user training that drive the price up.
Complex projects (multi-tenant SaaS, large-scale platforms, embedded systems) exceed €75,000 and can reach €250,000 according to aquilapp.fr. At this level, scalable architecture, GDPR security, and load testing alone account for 20 to 30% of the total budget.
Why do price gaps between vendors vary so widely?
Two quotes can differ by a factor of five for the same requirement. The reason is rarely "quality." It comes down to the vendor's business model: a Parisian IT services firm with offices in La Défense charges €600 to €900/day per developer. A structured offshore studio in Vietnam charges €200 to €350/day for an equivalent profile. The code itself has no idea what office rent costs.
I have seen €120,000 quotes brought down to €52,000 by switching from a Paris-region vendor to a Vietnamese team led by a French-speaking technical lead. Same stack (Next.js + PostgreSQL), same specs, same delivery timeline.
The cost items nobody puts in the quote
The initial budget is just the visible part. What derails software projects are the line items the sales rep forgets to mention at signing.
How much does custom software maintenance cost?
According to aquilapp.fr, annual maintenance represents 15 to 20% of the initial investment. On an €80,000 application, that means €12,000 to €16,000 per year, every year, without adding a single feature. Security patches, dependency upgrades, bug fixes: that is the bare minimum.
Over five years, maintenance can exceed the initial development cost. An off-the-shelf SaaS product includes these costs in the subscription. Custom software does not.
What integration costs are most often underestimated?
API integrations (existing ERP, CRM, accounting, SSO) consume between 10 and 25% of the budget depending on the number of systems to connect. According to the magram.fr guide, this is the line item that overruns most frequently because third-party APIs are rarely as well documented as promised.
User training (€2,000 to €10,000 according to ctdev.fr) and data migration round out the list. All told, these "invisible" items add 30 to 50% to the quoted budget.
| Cost item | Simple tool (€5-15K) | Business application (€15-75K) | Full SaaS (€75-250K) | Trend |
|---|---|---|---|---|
| Development | €3,000 to €10,000 | €10,000 to €50,000 | €50,000 to €180,000 | ↑ +15% vs 2024 |
| Testing & QA | €500 to €2,000 | €3,000 to €10,000 | €10,000 to €30,000 | ↑ GDPR requirements |
| API integrations | €0 to €2,000 | €3,000 to €15,000 | €10,000 to €40,000 | ↑ SaaS proliferation |
| Maintenance / year | €1,000 to €3,000 | €5,000 to €15,000 | €15,000 to €50,000 | → stable (15-20%) |
| Training | €0 | €2,000 to €8,000 | €5,000 to €15,000 | ↓ better UX design |
SOURCE: synthesis from aquilapp.fr, ctdev.fr, magram.fr · Updated 06/2026
Fixed price, time-and-materials, or MVP: which model protects your budget?
The contract type affects the final cost just as much as technical complexity. Three models dominate the French market, each carrying a different risk profile.
Should you choose fixed price or time-and-materials for custom software?
A fixed-price contract sets a price for a defined scope. Reassuring on paper, but according to magram.fr, the vendor builds in a 20 to 40% safety margin to cover the unexpected. You pay for that insurance even if everything goes smoothly.
Time-and-materials (billing at the actual daily rate) is more transparent but demands tight project management on the client side. I have seen T&M projects overrun by 60% because the client had nobody to challenge the estimates.
My approach at GoLive Software: a fixed-price scoping phase for the MVP (locked scope, fixed price), then managed time-and-materials for subsequent iterations. This hybrid model caps the initial risk without locking the project into a rigid specification document.
How does an MVP strategy reduce the upfront cost?
Launching an MVP rather than a full application cuts the initial budget by 40 to 60%, according to magram.fr. You build only the critical features, test with real users, then iterate.
A business CRM MVP can ship at €25,000 where the full version would cost €80,000. You validate the need before committing the bulk of the budget. Too many projects fail because the original specification did not match real-world usage.
Why I have my software built in Vietnam (and what it means for the price)
I have been working with Vietnamese development teams since 2015. My takeaway after dozens of delivered projects: at equal technical skill, the daily rate in Vietnam ranges from €200 to €350/day compared to €500 to €900/day in France for a senior developer.
How does Vietnam offer a better quality-to-cost ratio?
Vietnam trains more than 50,000 IT engineers every year (source: Statista, ICT workforce Southeast Asia). The country has positioned itself as a regional tech hub, driven by players like FPT Software (30,000+ employees) and VNG Corporation.
What matters is not the raw daily rate. It is the total cost of ownership. A senior Vietnamese team, led by a French-speaking lead, produces the same code quality as a French IT services firm. The difference shows up on the invoice: a business application at €60,000 in France comes in at €28,000 to €35,000 with a structured offshore team.
AI widens the gap even further. My devs use Claude Code and Cursor daily, compressing development time by 30 to 40% on repetitive tasks (CRUD, unit tests, refactoring). A senior Vietnamese developer augmented by AI now delivers what used to take two developers three years ago.
What are the real risks of offshore for a business application?
The number-one risk is not technical, it is organizational. Without a cultural and linguistic bridge between the French client and the Vietnamese team, misunderstandings pile up. I built GoLive Software to eliminate that friction: a French-speaking point of contact, specs written in French, daily standups aligned with the time difference (6 hours, morning calls in France / afternoon in Vietnam).
The second risk is confusing "cheap offshore" with "structured offshore." Traditional IT staffing firms that sell volume at €150/day produce turnover rates of 18 to 22% per year. A senior boutique team with a contractual commitment to team stability is a radically different model.
"A business application at €60,000 in France comes in between €28,000 and €35,000 in Vietnam, with the same stack, the same tests, the same timeline. The only variable is the developer's cost of living."
Vincent Roye, June 2026
My verdict: how much to budget based on your project
The price of custom software in 2026 depends on three variables: functional complexity, contract model, and team location. With a French IT services firm, multiply the ranges cited above by 1.5 to 2. With a senior offshore team in Vietnam, divide by two.
My advice: start with a fixed-price MVP (€15,000 to €30,000 with a Vietnam team), validate with your users, then iterate on time-and-materials.
I do not recommend jumping straight into a full €150,000 application without testing your business hypothesis on a lean V1 first. Modern stacks (Next.js, Supabase) make it possible to ship a functional MVP in 6 to 8 weeks. That is what I do for my clients, and it is what makes the difference between a project that lasts and a project that costs three times more than planned.
Frequently asked questions
How much does simple custom software cost in 2026?
A simple internal tool (dashboard, automation, business add-on) costs between €5,000 and €15,000 in France, and between €2,500 and €8,000 with senior offshore. This budget covers design, development, basic testing, and deployment.
Is custom software more expensive than SaaS over the long term?
Not necessarily. A SaaS charges €20 to €100/month/user. For 50 users over 5 years, that amounts to €60,000 to €300,000. Custom software at €80,000 with €15,000/year in maintenance comes to €155,000 over the same period. Custom becomes more cost-effective as the number of users or the duration of use increases.
What is the average timeline for developing custom software?
An MVP ships in 6 to 12 weeks. A full business application takes 4 to 8 months. A multi-tenant SaaS with integrations can take 8 to 14 months. The initial scoping phase (2 to 4 weeks) is the factor that compresses or extends the rest of the timeline.
Why do quotes vary so much from one vendor to another?
The gaps come from the daily rate (€200/day offshore versus €700/day at a Parisian IT firm), the estimated number of days, and the safety margins built into the fixed price. Always request the breakdown in person-days and the applied daily rate so you can compare objectively.
Can you have serious business software built offshore?
Yes, provided you choose a structured partner with a French-speaking technical lead and established code review processes. Vietnam trains over 50,000 IT engineers per year and hosts mature players like FPT Software. The risk is not the country, it is the model: a senior boutique team produces a radically different result than a volume-driven IT staffing firm.
Vidéos YouTube
Articles & ressources
- Quel budget pour un logiciel sur mesure ? · insolus.com
- Développement logiciel sur mesure : guide pour réussir son projet · anakeen.com
- Logiciel sur mesure prix : comment budgétiser votre projet en 2026 · aquilapp.fr
- Combien coûte un logiciel sur mesure ? · ctdev.fr
- Prix développement logiciel : coûts & budget 2025 · magram.fr
