Software maintenance contract cost for a custom app in Berlin in 2026

The verdict in three sentences

A software maintenance contract for a custom web app in Berlin runs in 2026 at 8 to 15% of the project cost per year, usually billed as a monthly retainer of 600 to 2,500 EUR. It covers bug fixes (SLA D+1 to D+3), security updates and an evolution hours bank, but rarely heavy new features. Well negotiated, it protects your initial investment; poorly scoped, it becomes a vague annuity. Here is how to structure it.

What maintenance covers (and does not)

A maintenance contract is not a magic subscription. The line between included fixes and billed evolutions is the most important clause in the contract.

The classic trap: signing a contract with no hours bank, then paying for every micro-change one by one. Demand a monthly, carry-over evolution hours quota.

2026 price grids by project size

The maintenance retainer is calibrated on the app's initial cost and the service level. Here are the ranges observed in Berlin.

Negotiation tip: paying maintenance yearly rather than monthly often saves 5 to 10%, and a 24-month commitment locks the rate.

Mini case study

Claire, CFO of an industrial SME in Berlin, had a production management app built for 72,000 EUR. Without maintenance, each incident went on a time-and-materials basis at 650 EUR/day with unpredictable delays. She signs a contract at 11%/year, i.e. 660 EUR/month (7,920 EUR/year), including a D+2 fix SLA and a bank of 4 evolution hours/month.

Math: the previous year she consumed 22 days of time-and-materials (14,300 EUR) for fixes and small evolutions. The contract caps spend at 7,920 EUR while guaranteeing timelines, i.e. 6,380 EUR saved and above all budget predictability. Unused evolution hours, carried over, fund a reporting module rework over two quarters.

FAQ

Retainer or time-and-materials, which to choose? The retainer (600-2,500 EUR/month) gives predictability and a guaranteed SLA, ideal for an app in production. Time-and-materials (450-700 EUR/day) fits occasional, unpredictable needs, but with no timeline commitment.

What happens without a maintenance contract? You stay at the mercy of the vendor's availability and per-unit pricing. A critical bug on a Friday night can wait days, and every fix is negotiated, which lengthens and inflates everything.

How is the 8 to 15% calculated? It reflects the cost of keeping a team ready to intervene quickly. The larger and better documented the project, the lower the percentage; the shorter the SLA (D+1), the higher it goes.

Is the hours bank carried over? It is negotiable and crucial. Demand carry-over of unused hours over 1 to 3 months: otherwise you pay for a service you don't use some months and run short in busy months.

Can I change maintenance vendor? Yes, provided you own the code, have up-to-date documentation and the access. Plan these clauses in the initial project to avoid lock-in and ease a handover.

Let's scope your project. Send us the initial development cost, the app's criticality and the target SLA: we'll build a maintenance contract with retainer, hours bank and clear timelines. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.