The verdict in three sentences
A monthly fixed fee (1,200 to 4,000 EUR, about 1,350 to 4,500 USD) suits stable applications with regular, predictable change needs, because it brings an SLA and a smoothed budget. Time and materials (day rate of 450 to 700 EUR, 500 to 800 USD) fits periods of heavy transformation, when scope changes every month. In both cases, budget 15 to 20% of the initial cost per year and insist on a priced exit clause.
The two models compared
Application maintenance covers three kinds of work: corrective (bugs), adaptive (dependency, browser, PHP or Node.js upgrades) and evolutive (new features). The contract must state how each one is billed.
| Criterion | Time and materials | Fixed fee with committed capacity |
|---|---|---|
| 2026 price | day rate 450 to 700 EUR | 1,200 to 4,000 EUR per month |
| Capacity | days actually used | 2 to 8 days per month guaranteed |
| Incident SLA | rarely contracted | response 4 h critical, 2 days minor |
| Budget predictability | low | high |
| Scope flexibility | very high | medium (capped rollover) |
| Service credits | usually none | 2 to 10% of monthly fee if SLA missed |
| Overrun risk | borne by the client | shared |
How much to budget by application size
The 15 to 20% of initial cost per year benchmark works well for an SME business application. Below 10%, the application decays: outdated dependencies, unpatched vulnerabilities, technical debt that makes each later change more expensive.
| Initial application cost | Annual maintenance budget (15-20%) | Equivalent monthly fee | Equivalent T&M days (600 EUR rate) |
|---|---|---|---|
| 30,000 EUR | 4,500 to 6,000 EUR | 375 to 500 EUR | 7 to 10 days |
| 60,000 EUR | 9,000 to 12,000 EUR | 750 to 1,000 EUR | 15 to 20 days |
| 120,000 EUR | 18,000 to 24,000 EUR | 1,500 to 2,000 EUR | 30 to 40 days |
| 250,000 EUR | 37,500 to 50,000 EUR | 3,100 to 4,200 EUR | 62 to 83 days |
| 400,000 EUR | 60,000 to 80,000 EUR | 5,000 to 6,700 EUR | 100 to 133 days |
The clauses that protect the IT leader
A good maintenance contract is judged by what happens when things go wrong. Several clauses make the difference.
| Clause | What to require | 2026 order of magnitude |
|---|---|---|
| Service levels | response and fix times by severity | 4 h / 1 day / 5 days |
| Service credits | capped but real | 2 to 10% of the month, 15% annual cap |
| Unused day rollover | allowed over 1 to 3 months | 20 to 30% of capacity |
| Exit and handover | priced transition plan and support | 5 to 15 days included or at day rate |
| Documentation | updated with each release | architecture, deployment, runbook |
| Code ownership | IP assignment and Git repository access | at no extra cost |
Without an accessible Git repository and up-to-date documentation, switching provider costs 15 to 30 days of takeover in practice, i.e. 9,000 to 18,000 EUR.
Mini case study
Nicholas, IT director of a 180-employee distribution company in Manchester, must renew maintenance on his ordering portal, which cost 140,000 EUR to build. In 2025, time and materials used 46 days at 620 EUR, i.e. 28,520 EUR, with unplanned peaks in November and incidents fixed in 2 days on average.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
He compares a fixed-fee offer at 2,100 EUR a month for 3.5 guaranteed days, with a 4-hour SLA on critical incidents: 25,200 EUR a year, or 42 days of capacity. Any 4 extra days are billed at 580 EUR, i.e. 2,320 EUR. Total: 27,520 EUR, 1,000 EUR less than time and materials, with a smoothed budget and a contractual SLA. He picks the fixed fee, with 30% rollover over 2 months.
FAQ
Is a fixed fee always cheaper than time and materials?
No. If your needs are very irregular, you may pay for unused days. A fixed fee becomes attractive from about 2 days of steady monthly work.
What day rate is reasonable in 2026?
In the UK, 450 to 550 EUR (380 to 470 GBP) for an experienced developer at a regional agency, 600 to 700 EUR for a senior or architect in London. In the US, expect 100 to 150 USD an hour. Above those levels, ask for the expertise to be justified.
Should hosting be included in maintenance?
It is convenient, but keep separate lines. Hosting an SME application costs 80 to 600 EUR a month depending on the required redundancy.
What commitment length should we choose?
12 months renewable with 3 months' notice is the usual balance. A 36-month commitment can lower the fee by 5 to 10%.
How do we measure provider quality?
Track 4 indicators monthly: SLA compliance, number of regressions, average delivery time for changes, and test coverage (target above 60%).
Let's scope your project. Send us your application scope and your current maintenance usage history: we will propose a fixed fee of 1,200 to 4,000 EUR a month with SLAs or a well-governed time and materials model. 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.
