How much does it cost to maintain custom software?
As a benchmark, annual maintenance runs about 15–20% of the original build cost per year for typical business software — so a £40k build is roughly £6k–£8k a year to keep current. It's not a surprise; it's the planned cost of an asset, and most of a system's lifetime cost comes after launch.
Source: industry benchmarks — ~15–20% of build/year for SMB software; ~60% of total software cost is post-launch.
What maintenance costs.
- ~15–20% of build/year for typical SMB software — the long-standing benchmark.
- Higher for complex or regulated systems — 20–30%+.
- Most cost is post-launch — around 60% of lifetime cost comes after go-live.
- Lower with good build quality — clean code and docs cost less to keep.
Why it's not optional.
Software lives in a moving world — browsers and dependencies change, security holes appear, and your business evolves. Maintenance is hosting, security patches, bug fixes and small enhancements that keep the system working and safe. Skip it and the asset you paid for quietly degrades into a liability.
Common questions.
How much does it cost to maintain custom software per year?
As a benchmark, about 15–20% of the original build cost per year for typical business software — so a £40k build is roughly £6k–£8k a year. Complex or regulated systems can run higher.
Why does custom software need ongoing maintenance?
Because the world around it changes — browsers, dependencies, security — and your business evolves. Around 60% of a system's lifetime cost comes after launch. Without upkeep, it degrades and becomes a security and reliability risk.
What does software maintenance include?
Hosting and uptime, security patches and updates, bug fixes, and small enhancements as the business changes. A managed retainer packages these into one predictable fee.
Can I skip maintenance to save money?
You can, but it's a false economy — unmaintained software accumulates security holes and breakage, and fixing it reactively costs more than maintaining it. The asset you paid for slowly becomes a liability.
Is maintenance the same as a retainer?
A retainer is how maintenance is usually delivered — a monthly fee covering hosting, security, fixes and a roadmap, with the team that built it. See our retainer vs project page.
How can I keep maintenance costs down?
With good build quality from the start — clean code, documentation and the right architecture cost far less to maintain than a rushed or poorly-built system.
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Related questions
Keep the build an asset.
Book a call — we'll be clear about what your system needs each year to stay secure and current.