The verdict in three sentences
A maintenance retainer is not optional: an unmaintained institutional website becomes a security and reputation risk within months. In 2026, budget 8 to 20% of the project cost per year, i.e. roughly 2,500 to 15,000 USD annually depending on scope. The right call is between a retainer (predictable) and time-and-materials (flexible), and on the precision of the SLA.
What a retainer covers
A vague retainer breeds disputes. Every building block must be named and bounded.
| Scope | Content | Frequency |
|---|---|---|
| Corrective | Bugs, regressions | On demand |
| Evolutive | Small enhancements | Monthly / quarterly |
| Security | Updates, patches | Continuous |
| Hosting | Server, CDN, backups | Continuous |
| Monitoring | Uptime, alerts | 24/7 |
| Support | Help desk, tickets | Business hours |
Annual cost and SLA levels in 2026
The percentage depends on criticality and change frequency. A stable showcase site trends toward 8%; an active portal toward 20%.
| Site type | Project cost (USD) | Retainer/year (USD) |
|---|---|---|
| Institutional showcase | 18,000 – 30,000 | 2,500 – 5,000 |
| Site + multilingual CMS | 30,000 – 48,000 | 4,000 – 8,500 |
| Portal + integrations | 48,000 – 72,000+ | 7,000 – 15,000+ |
| SLA level | Uptime | Response time |
| Standard | 99.5% | 24–48 business h |
| Enhanced | 99.9% | 4–8 business h |
| Critical | 99.95% | < 2 h, on-call |
Mini case study
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Karim, CTO of a services group in New York, must budget maintenance after launching a portal costing 58,000 USD. He weighs a retainer at 10,000 USD/year (enhanced SLA, 99.9% uptime, evolutive included) against time-and-materials billed per ticket. Over the prior year, the T&M equivalent would have cost about 13,000 USD given the volume of changes. Karim picks the retainer: an estimated 3,000 USD saving and a smoothed budget, easier to defend to the board.
FAQ
What share of the project should go to maintenance? Between 8 and 20% per year in 2026. A stable showcase site trends toward 8-10%; a high-change portal toward 15-20%. Below 8%, security is usually underfunded.
Retainer or time-and-materials? The retainer for predictability and a steady volume of changes; T&M for occasional, unpredictable needs. Many contracts combine a retainer base with reserve T&M days.
Does security alone justify a retainer? Yes. Without updates and patches, a CMS becomes vulnerable within months. The cost of an incident (defacement, data breach) far exceeds the annual retainer.
What must the SLA guarantee? Uptime (99.9% common for institutional sites), response time by criticality, backup frequency and restore time. These commitments must be quantified and enforceable.
Does the retainer include hosting? Often yes in a managed package, but check: server, CDN, backups and monitoring may be billed separately (roughly 100 to 400 EUR/month in Europe, or 25,000-75,000 FCFA/month in West Africa depending on load).
Let's scope your project. Tell us your site cost, target SLA level and change frequency, and we'll propose a scoped maintenance retainer. 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.
