The verdict in three sentences
The real cost of software is not its build price but its lifecycle cost: annual maintenance weighs 12 to 20% of the development cost, every year, for life. This budget covers fixes, security, dependency updates, hosting and support — functional evolution is budgeted on top. Ignoring maintenance guarantees unmanageable technical debt within 18-24 months.
Maintenance line items in detail
Maintenance is not a single line: it breaks into distinct items, some incompressible (security) and some variable (support, evolution). Indicative 2026 split for software with a 100,000 EUR build.
| Maintenance item | Share of maintenance | Estimated annual cost (EUR) |
|---|---|---|
| Fixes & bugs | 20 – 25% | 3,000 – 4,500 |
| Security & compliance | 20 – 25% | 3,000 – 4,500 |
| Dependency updates | 15 – 20% | 2,500 – 3,500 |
| Hosting & infrastructure | 15 – 20% | 2,500 – 3,500 |
| User support | 10 – 15% | 1,500 – 3,000 |
| Monitoring & backups | 5 – 10% | 1,000 – 2,000 |
Total maintenance: about 14,000 to 18,000 EUR/yr, i.e. 14 to 18% of the build. Functional evolution (new features) is added per the roadmap.
The 5-year TCO
Software costs far more than its sticker price. Over 5 years, maintenance can equal the initial build. Here are three 2026 scenarios.
| Scenario (build) | Maint./yr | Evolution/yr | 5-year TCO (EUR) |
|---|---|---|---|
| Internal tool (60,000) | 9,000 | 5,000 | 130,000 |
| B2B application (120,000) | 20,000 | 12,000 | 280,000 |
| SaaS platform (200,000) | 36,000 | 25,000 | 505,000 |
In these examples, cumulative maintenance + evolution exceeds the initial build cost by year 4 or 5. Hence the importance of budgeting it from the start.
Mini case study
Éric, CFO of a logistics SME in Nantes, had an internal TMS built for 120,000 EUR. He budgeted no maintenance. From year 2, security flaws and obsolete dependencies force an emergency upgrade billed at 35,000 EUR, far more than preventive maintenance of 20,000 EUR/yr. By smoothing it into a maintenance contract from delivery, he would have avoided the spike and secured his application. Over 5 years, preventive maintenance (100,000 EUR) stays cheaper than cumulative curative fixes (≈ 130,000 EUR).
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FAQ
Why does maintenance represent 12 to 20% of the build?
Because software lives in a shifting environment: security flaws, evolving dependencies, changing browsers and OSes. Without upkeep, it degrades even with no new feature.
Can we skip maintenance in year one?
Not advised: it is often the year you discover residual bugs and the first security updates. Light maintenance in year 1 is a minimum.
What is the difference between maintenance and evolution?
Maintenance keeps the existing system working; evolution adds new features. Budget both separately to keep visibility.
Is hosting included in maintenance?
Often yes, but check the contract. Budget 2,500 to 3,500 EUR/yr for a mid-sized B2B application in 2026, more depending on load.
How do we reduce maintenance cost?
Clean, tested and documented code with up-to-date dependencies cuts maintenance by several points. Build quality is the best anti-maintenance investment.
Let's scope your project. Tell us the scope of your existing or upcoming application: we cost a suitable maintenance contract and a projected 5-year TCO. 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.
