Maintenance Contracts for Custom Business Apps: Pricing and SLAs in 2026

The verdict in three sentences

An application maintenance contract typically costs 15 to 20% of the app's initial build cost per year, and that ratio climbs fast when the contract is neither measured nor capped. For a 4-year-old business app used by 80 people, the renegotiation should focus on four concrete points: the day allowance, SLAs by severity level, security updates and exit terms. A well-written contract often cuts the bill by 20 to 35% while improving service.

What you really pay for in a maintenance contract

After 4 years, a business app has accumulated debt: outdated dependencies, a framework version at end of support, incomplete documentation. Maintenance covers three families of work that must be separated in the contract, otherwise everything ends up billed at the same rate.

• Corrective maintenance: fixing bugs, with turnaround times tied to severity.
• Preventive and security maintenance: monthly dependency updates, vulnerability patches, framework and database upgrades.
• Enhancements: small functional changes requested by the business, drawn from a day allowance.

The first question for your current provider: how many days were actually used each year, and on what. It is common to find that 60% of billed time went to enhancements that should have been quoted separately, or that security updates were never done.

The SLAs to demand, level by level

An SLA without a precise severity definition protects no one. Here is a realistic grid for an 80-user app without 24/7 on-call.

Add a monthly report (tickets opened and closed, time spent, updates applied, dependency status) and a quarterly review with IT. Without metrics, contractual penalties stay theoretical.

Exit terms: the clause that sets your negotiating power

If you cannot change provider, you cannot negotiate. The exit clause should guarantee:

• permanent access to the source code repository (Git) hosted by you or in your name;
• up-to-date operations documentation: architecture, deployment procedure, environment variables, backups;
• a transition period of 1 to 3 months with knowledge transfer, at a price fixed at signature;
• ownership of hosting accounts, domain names and certificates in your company's name.

This is also the time to weigh your options: renew, switch provider or rebuild. A 4-year-old app on an end-of-life framework sometimes costs more to maintain for 3 years than to rebuild on a modern stack. At Kolonell, a custom build ranges from 2,500,000 to 15,000,000+ FCFA (EUR 3,810 to 22,870+) depending on complexity (simple EUR 3,810 to 6,100, medium EUR 6,100 to 10,670, complex EUR 10,670 to 22,870+), followed by maintenance at 35,000, 75,000 or 120,000 FCFA per month (EUR 53, 114 or 183). Taking over an existing app, audit included, is priced in the quote.

Mini case study

Mark, IT director of a mid-sized distribution company in Rotterdam, pays EUR 32,000 a year for maintenance set at 18% of a business app delivered for EUR 180,000 four years ago. He reviews the last 12 months.

• Actual usage: 14 days of fixes and 9 days of enhancements, 23 days in total. At EUR 700 per day, the value delivered is EUR 16,100.
• Security updates: no framework upgrade in 2 years, an uncovered risk.
• New contract proposed: 20-day allowance (EUR 14,000), monthly security updates included (EUR 300 per month, EUR 3,600 a year), 4-hour blocking SLA, total EUR 17,600 per year.

Savings reach EUR 14,400 a year, or 45%, with better-defined service. Over a new 3-year contract, that is EUR 43,200, enough to fund part of a rebuild if it becomes necessary.

FAQ

What percentage of build cost is reasonable for maintenance?

15 to 20% per year is the 2026 market norm in Western Europe. Above 20% without regular enhancements, ask for a breakdown of days used and move to an allowance.

What happens to unused days at year end?

Negotiate carrying over 25 to 50% into the next year, or converting them into a security audit. Without a written clause, they are usually lost.

Is a 4-hour SLA enough for a blocking incident?

For an app used during business hours, yes. 24/7 on-call often costs EUR 800 to 2,000 more per month and is only justified for a critical service.

How much does switching maintenance provider cost?

Allow 5 to 15 days of takeover, including code audit and documentation, so EUR 3,500 to 12,000 depending on the app's condition. A good exit clause sharply reduces that figure.

When is rebuilding better than maintaining?

When the framework is no longer supported, when more than 30% of maintenance goes to working around technical debt, or when requested enhancements exceed 40 days a year. A 3 to 5 day audit settles the question.

Let's scope your project. Send us your current contract and ticket history, and we will compare maintaining, taking over or rebuilding with a realistic timeline. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.