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Maintaining a business app combines hosting (a few tens to a few hundred euros a year), security updates, bug fixes and new features. For budgeting, a conservative assumption is to set aside 10 to 20% of the initial development cost each year, new features included.
Maintenance is the most frequently underestimated line in a software budget. It costs far less than development, but it comes back every year, and an app that is not maintained degrades faster than people expect. Here is what it covers, how it is billed, and how to budget for it without unpleasant surprises.
The four parts of maintenance
People often put everything under one word. In practice, there are four separate cost lines, and they are not managed the same way.
| Cost line | What it covers | How it is billed |
|---|---|---|
| Hosting and services | Server, database, backups, domain name, email sending | Directly by the providers, in your name: a few tens to a few hundred euros a year |
| Technical maintenance | Dependency updates, security patches, monitoring | Yearly fixed fee or time spent |
| Corrective maintenance | Fixing issues found in production | Included for 3 months after go-live, then fixed fee or time spent |
| New features | New functions, screens and connections | A quote for each request, or a yearly budget |
Third-party services billed by usage (AI, text messages, e-signature, mapping) come on top, depending on your consumption. They are paid by you and billed by the providers themselves.
Why technical maintenance cannot be skipped
A modern app is built on open-source building blocks: a language, a framework, libraries. Those blocks have a lifespan. For example, the Node.js project states that an LTS (long-term support) release typically receives critical bug fixes for a total of 30 months (Node.js release schedule, checked in October 2026). After that, you have to move to a newer version.
The same goes for interface libraries, the database and connected services, whose APIs change. Doing these updates regularly takes little time. Putting them off for three years turns routine upkeep into an upgrade project.
What yearly budget to plan
There is no single price: the budget depends on the size of the app, the number of connections and how often you want it to evolve. For a first estimate, here is the working assumption I suggest, to be refined during scoping.
| App profile | Initial cost | Yearly budget assumption (excluding hosting) |
|---|---|---|
| Focused, stable business app | $6,800 to $13,500 (€6,000–€12,000)excl. VAT | About 10% of the initial cost |
| Complete business app, a few new features a year | $13,500 to $22,400 (€12,000–€20,000)excl. VAT | About 15% |
| ERP or highly connected app, frequent changes | $16,800 to $56,000 (€15,000–€50,000)excl. VAT | 15 to 20% or more |
An illustrative example, with made-up amounts: an app at $18,000 (€16,000)excl. VAT with a 15% assumption means €2,400 a year for maintenance and small improvements, plus a few hundred euros of hosting. These figures are orders of magnitude for building a budget, not a price list: the actual fee is quoted for your app.
To estimate the initial cost of your project, use the estimator.
What brings the bill down
Most of the cost of maintenance is decided during development.
- A mainstream stack. React, TypeScript, Node.js and PostgreSQL are widely used: updates are documented and other developers can take over the code.
- Fewer dependencies. Every added library is one more block to watch. I only add one when it brings a real benefit.
- Tests on the critical parts. Pricing, invoicing, access rights: automated tests make it possible to update without fear of breaking things.
- Hosting in your name. You keep control of the accounts, invoices and backups, as explained on the reversibility page.
- Up-to-date documentation. It shortens every intervention, and therefore its cost.
When a maintenance contract is not necessary
Not everyone needs a fixed fee. If your app is simple, used by a small team, with no sensitive data and no connection to external services, on-demand work two or three times a year may be enough. I will also say this: for a very standard tool (email, accounting), an off-the-shelf product maintained by its vendor remains cheaper than custom software you have to maintain.
On the other hand, a maintenance contract becomes essential as soon as the app handles payments, large volumes of personal data or a process whose downtime stops the business. In that case, security is not optional: see also backups and disaster recovery.
How maintenance works with me
- Three months of support included after the production launch, to fix issues within the delivered scope.
- Choice of formula afterwards: a fixed fee, with its content defined together based on your app, or hourly billing.
- Planned updates of the technical building blocks, grouped together to limit interruptions.
- New features quoted in advance, approved by you before any work starts.
The terms and the price list are on the pricing page.
Frequently asked questions
Can an app run without maintenance?
For a few months, yes. For several years, no: the technical building blocks it relies on stop receiving fixes, vulnerabilities are discovered, and browsers and connected services change. An unmaintained app ends up costing more to bring back up to date than it would have cost to maintain.
What does the support included after go-live cover?
In my projects, three months of support are included after the production launch: fixing issues found within the delivered scope and helping your team get started. New features requested during that period are quoted separately.
Can another provider take over maintenance?
Yes. The source code and rights are transferred to you once the project is paid in full, and a mainstream stack (React, TypeScript, Node.js, PostgreSQL) is easy for another developer to pick up, provided the code is documented.
Should we sign a maintenance contract or pay as we go?
A fixed fee suits a critical app that evolves regularly: you get a predictable budget and agreed response times. Hourly billing suits a stable app that rarely changes, where interventions remain occasional.