The verdict in three sentences
A fix-only retainer (300 to 800 EUR a month) is enough for a stable, lightly used application with no planned changes. As soon as the tool drives revenue or changes every quarter, application maintenance with a bank of hours (1,500 to 4,000 EUR a month for 15 to 40 h, about 1,600 to 4,400 USD) costs less than ad hoc work. A maintenance contract with an SLA (3,000 to 8,000 EUR a month) is justified when one hour of downtime costs you more than the monthly fee.
The three contract levels
Third-party application maintenance (TMA in French) covers bug fixing, technical maintenance (dependency updates, security, hosting) and enhancements. The common 2026 rule: budget 15 to 20 % of the development cost per year. An application that cost 80,000 EUR therefore calls for 12,000 to 16,000 EUR a year.
| Plan | 2026 monthly price (excl. VAT) | Scope | Response time | Who it suits |
|---|---|---|---|---|
| Fix only | 300 to 800 EUR | Blocking bugs, security updates | 1 to 2 business days | Stable internal tool, under 50 users |
| Bank of hours (15 h) | 1,500 to 2,000 EUR | Fixes + 15 h of enhancements or support | 8 business hours | SMEs, 1 enhancement a month |
| Bank of hours (40 h) | 3,000 to 4,000 EUR | Fixes + 40 h, monthly review | 4 to 8 business hours | App evolving every quarter |
| Maintenance with SLA | 3,000 to 8,000 EUR | 4-hour response, on-call, monitoring | 4 h, evening and weekend on-call | Critical app, external customers |
| On-demand work | 600 to 850 EUR per day | One-off, no commitment | Subject to availability, often 1 to 3 weeks | Very rare use |
In Rennes, an experienced developer at an IT services firm or agency bills 550 to 750 EUR per day; in Dublin or Toronto, rates are often 10 to 30 % higher. A bank of hours usually brings the effective hourly cost down to 90 to 110 EUR, against 100 to 120 EUR for on-demand work billed by the half day minimum.
What a good contract must specify
Clauses matter more than price. A poorly drafted maintenance contract makes you dependent on the provider and makes switching expensive.
| Clause | What to require | Common trap |
|---|---|---|
| Severity levels | Blocking, major, minor, with written definitions | Everything rated minor by default |
| SLA | Separate response time and resolution time | Only response time guaranteed |
| Penalties | 5 to 10 % of the monthly fee per breach, capped | No penalties |
| Hour rollover | Unused hours carried over 1 to 3 months | Hours lost every month |
| Code ownership | IP assigned to the client, code in your own Git repository | Code held by the provider only |
| Reversibility (exit plan) | Documentation, access, 5 to 10 days of handover at contract end | Exit billed at full price |
| Term and termination | 12 months, 3-month notice | 36-month automatic renewal |
The exit clause is the one that protects you most: at contract end, the provider hands over up-to-date code, operating documentation and access, and transfers knowledge to the successor. Without it, switching providers often costs 10 to 20 days of audit and catch-up work.
Mini case study
Sophie, managing director of a food logistics SME in Rennes (120 employees), had a route-management application built for 90,000 EUR. Year one on on-demand work: 7,200 EUR of fixes plus 22 days of enhancements at 650 EUR, so 14,300 EUR, totalling 21,500 EUR, with 2 to 3 weeks of waiting for each request. She switches to a 20-hour bank of hours at 2,000 EUR a month, 24,000 EUR a year: for 2,500 EUR more, requests are handled within 8 business hours and a monthly review anticipates enhancements. A single half day of blocked routes used to cost her about 4,000 EUR in delayed deliveries.
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FAQ
What is the difference between application maintenance and corrective maintenance?
Corrective maintenance fixes what no longer works. Full application maintenance adds technical upkeep and enhancements, with a response-time commitment; it represents 15 to 20 % of the development cost per year.
Should the original developer handle maintenance?
It is often more efficient in year one, since they know the code. Still require an exit clause and a Git repository in your name so you remain free to switch.
What happens to unused hours?
Negotiate a 1 to 3 month rollover. Beyond that, a quarterly review lets you adjust the volume, for example from 20 h to 15 h a month.
Does an SME need a 4-hour SLA?
Only if an outage stops operations or affects your customers. Work out the cost of one hour of downtime: if it exceeds 500 to 1,000 EUR, a 4-hour SLA at 3,000 EUR a month becomes rational.
Does Kolonell offer maintenance contracts?
Yes, for applications we build and for taking over existing ones, after a 3 to 5 day audit. Our contracts include an exit clause and code ownership for the client.
Let's scope your project. Send us a description of your application, its number of users and the cost of one hour of downtime: we will propose the right maintenance plan, with SLA and exit clauses. 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.
