The verdict in three sentences
A delivered application is not a finished project: it is a product to maintain. In 2026, application maintenance (TMA) runs at 15 to 25 % of build cost per year, depending on whether you take corrective-only or a full pack with managed operations. For a 50,000 EUR build, expect 7,500 to 12,500 EUR/year, or 625 to 1,040 EUR/month.
Maintenance grid by scope in 2026
The rates below apply to annual build cost. These are 2026 orders of magnitude for a custom application.
| Maintenance scope | % of build/year | For a 50,000 EUR build | What's included |
|---|---|---|---|
| Corrective only | 12 % | 6,000 EUR/year | Blocking bugs, critical security |
| Corrective + evolutive | 20 % | 10,000 EUR/year | + small changes, version upgrades |
| Full + 24/7 managed ops | 24 % | 12,000 EUR/year | + monitoring, on-call, SLA |
| Premium + dedicated L3 | 28 % | 14,000 EUR/year | + dedicated expert, stronger guarantees |
The most common scope for an SME is corrective + evolutive at 20 %, which keeps the app current and alive without over-sizing the budget.
Cost breakdown and monthly retainer vs day pack
Maintenance groups several items you must split to pick the right contract.
| Item | Share of TMA | Monthly retainer | Day pack |
|---|---|---|---|
| Hosting + infrastructure | 20 % | Included | Rebilled |
| Security updates | 15 % | Included | On consumption |
| L2/L3 support | 25 % | Included, SLA | On demand |
| Small changes | 30 % | Capped/month | Deducted from pack |
| Framework version upgrades | 10 % | Planned/year | On quote |
The monthly retainer suits critical applications needing an SLA and guaranteed responsiveness. The day pack (e.g. 15 days/year) is more flexible and economical for a stable, low-demand application.
Mini case study
Claire, CFO of an industrial SME in Lyon, must budget maintenance for a business app delivered at 50,000 EUR. She hesitates between the day pack and the retainer. Over the prior year, her teams raised 18 tickets and asked for 3 small changes. On a corrective + evolutive retainer at 20 %, the cost is 10,000 EUR/year (833 EUR/month) with an 8-business-hour SLA. On a 15-day pack at 550 EUR, she pays 8,250 EUR but with no delay guarantee. She picks the retainer: the 1,750 EUR gap buys responsiveness that, on a production app, avoids a day of downtime billed far higher in lost activity.
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FAQ
How much does SaaS maintenance cost in 2026?
The rule is 15 to 25 % of build cost per year. For a 50,000 EUR application, that's 7,500 to 12,500 EUR/year.
What's the difference between corrective and evolutive?
Corrective covers bugs and security flaws; evolutive adds small improvements and version upgrades. The corrective + evolutive pack (20 %) is the most requested.
Monthly retainer or day pack?
The retainer guarantees an SLA and suits critical apps; the day pack (e.g. 15 days/year at 550 EUR) is cheaper for a stable app. The gap is around 15 to 20 %.
What happens without maintenance?
Security flaws go unpatched, dependencies age, and an outage can freeze the business. A single day of downtime often costs more than a year of corrective maintenance.
Is hosting included in maintenance?
In a retainer, hosting and infrastructure (about 20 % of the maintenance budget) are usually included. In a day pack they are often rebilled separately.
Let's scope your project. Share your application's build cost and expected service level (SLA, on-call): we size the ideal maintenance plan. 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.
