Client Portal Maintenance (TMA) Cost in Berlin in 2026

The verdict in three sentences

Application maintenance (TMA) for a client portal costs, in 2026, between 12 and 20% of the build cost per year, i.e. a retainer of 800 to 4,000 EUR/month. It covers fixes, enhancements, monitoring and security upgrades, with SLAs of 4 to 24 h depending on criticality. Without maintenance, a portal degrades within 12 to 18 months: it is a fixed cost to budget, not an option.

What a maintenance contract actually covers

Many projects stop at delivery and discover too late that maintenance was not planned. A serious maintenance contract distinguishes fixes (restoring service), enhancements (new features) and supervision (monitoring, backups, security). It is this scope, not just the price, that you must compare between vendors.

Retainer or time-and-materials: which to choose

Two models coexist. The retainer offers a predictable budget and a service commitment (SLA), ideal for a portal in stable production. Time-and-materials bills by hours spent, more flexible for an intensive enhancement phase but unpredictable. Many companies combine a supervision retainer with time-and-materials for large projects.

Mini case study

Thomas is IT director of a services group in Berlin, with a client portal delivered at 90,000 EUR. He hesitates between subscribing to nothing and a maintenance retainer. Without maintenance, a single unhandled blocking outage already cost him a day of downtime: about 4,000 EUR in lost productivity and a client incident. He opts for a maintenance retainer at 15%/year, i.e. 13,500 EUR/year (1,125 EUR/month), with a 4 h SLA on critical incidents and a 2 days/month enhancement quota. Over the year, he handles 9 fixes and 18 small enhancements at no extra cost, avoids at least 2 major incidents (8,000 EUR avoided) and secures his portal with 4 upgrades. The retainer pays for itself with the first incident avoided.

FAQ

How much does portal maintenance cost in 2026?

Between 12 and 20% of the build cost per year, i.e. 800 to 4,000 EUR/month depending on size and criticality. A 90,000 EUR portal is maintained at around 13,500 EUR/year.

What happens if I skip maintenance?

The portal degrades: uncorrected security flaws, browser incompatibilities, unhandled outages. A portal without maintenance becomes risky within 12 to 18 months.

Retainer or time-and-materials, which is cheaper?

The retainer is more predictable and includes an SLA; time-and-materials (day rate 500 to 900 EUR) is more flexible but unpredictable. For stable production, the retainer is generally the best cost/peace-of-mind ratio.

What does an SLA guarantee?

A maximum time to acknowledge and resolve by criticality: 4 h for a blocking incident, up to 24 h for a minor request. That contractual commitment is what distinguishes real maintenance from ad-hoc repair.

Are enhancements included?

Small enhancements are, via a monthly quota (often 1 to 2 days); major enhancements (new modules) are subject to a separate quote. Check that quota before signing.

Let's scope your project. Share your portal's cost, its criticality and the SLA level you want: we propose a calibrated maintenance retainer. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.