The verdict in three sentences
A maintenance contract (TMA) typically costs 15 to 20% of the build price per year in 2026: an app delivered at 60,000 EUR is maintained at around 9,000 to 12,000 EUR/year. This budget covers corrective, evolutive, security work, dependency updates and the SLA, not just firefighting. Not maintaining means letting technical debt and vulnerabilities pile up, with a catch-up cost that far exceeds the saving.
The scope of a maintenance contract
A good contract clearly states what's included. Confusion over scope is the leading source of disputes.
| Item | Included in a standard TMA | Detail |
|---|---|---|
| Corrective maintenance | Yes | Bug fixing |
| Security updates | Yes | Patches, dependencies, CVEs |
| Adaptive maintenance | Often | Browser/OS compatibility |
| Supervision / monitoring | Depends on tier | Alerts, uptime |
| Evolutive maintenance | Optional / T&M | New features |
| Hosting | Sometimes separate | Infra + backup |
| SLA (time guarantee) | Depends on level | Recovery time |
Fixed-fee, time-and-materials or per-ticket?
Three models coexist, each suited to a need and criticality profile.
| Model | How it works | 2026 cost | Ideal for |
|---|---|---|---|
| Monthly fixed fee | Fixed envelope, defined scope | 750 - 3,000 EUR/month | Critical app, predictable budget |
| Time-and-materials (pre-bought days) | Block of days consumed | 600 - 1,000 EUR/day | Frequent changes |
| Per-ticket | Pay per intervention | 90 - 150 EUR/hour | Stable app, few incidents |
| Hybrid fee + T&M | Base + evolutions apart | Combined | Most SMEs |
The fixed fee secures responsiveness; T&M gives flexibility for evolutions. Many SMEs choose a hybrid: a flat base for security and fixes, plus a pool of days for evolutions.
Monthly cost by criticality and SLA levels
The service level (SLA) strongly affects price. A showcase app doesn't need the same guarantee as a production business tool.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
| Criticality | Typical SLA (recovery) | 2026 fixed fee (EUR/month) |
|---|---|---|
| Low (showcase site) | 48-72 business hours | 300 - 800 |
| Medium (internal app) | 8-24 business hours | 800 - 1,800 |
| High (production business tool) | 4 business hours | 1,800 - 3,500 |
| Critical (24/7) | 1-2 h, on-call | 3,500 - 8,000+ |
Mini case study
Laura, operations manager of a logistics SME in Lille, had a route-tracking tool built for 70,000 EUR. She hesitates to sign a TMA at 1,400 EUR/month (16,800 EUR/year, i.e. 24% of the build, 8 h SLA). One uncovered incident already costs her 3 days of downtime: delayed invoicing, 12,000 EUR of blocked cash and 4 emergency T&M days at 900 EUR (3,600 EUR). Over a year, two such incidents exceed the cost of the TMA. She signs a hybrid contract: a security/fix base at 1,100 EUR/month plus 10 pre-bought evolution days, to control both risk and budget.
FAQ
Why 15-20% of the build per year? Because dependencies (frameworks, libraries) evolve, vulnerabilities appear and browsers change. Without maintenance, an app degrades within 12-24 months. The ratio is a market order of magnitude, adjustable by criticality.
What happens without maintenance? Technical debt accumulates: outdated unpatched dependencies (vulnerabilities), incompatibilities, and an upgrade cost that can reach 30 to 50% of a new build. The security risk is the most serious.
Does the fixed fee cover new features? Rarely in full. Corrective and security work are in the fee; evolutions (new features) are handled via T&M or a dedicated quote. Clarify this before signing to avoid disputes.
Can you switch maintenance providers? Yes, provided you have access to the code, documentation and environments. Require reversibility from delivery: accessible Git repo, technical docs, credentials. Without them, you're locked in.
How do you set the right SLA? Based on the cost of an hour of downtime for your business. A production business tool justifies a 4 h SLA; a showcase site is fine with 48-72 h. Don't overpay for a 24/7 SLA you don't need.
Let's scope your project. Tell us the application type, its criticality and the SLA you want, and we'll frame a tailored maintenance contract (fixed-fee, T&M or hybrid) with clear 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.
