Every credible agency quotes maintenance at 15–25% of build cost per year, and every first-time buyer wonders if it is padding. It is not — and understanding where the money goes helps you negotiate better contracts and healthier software.
Where the 15–25% actually goes
| Share | Category | Examples |
|---|---|---|
| ~40% | Corrective + adaptive | Bug fixes, OS/browser changes, dependency and security updates, API changes |
| ~40% | Perfective | Small features, UX tweaks, report changes — the "can we just add…" stream |
| ~20% | Preventive | Refactoring, performance care, monitoring — the work that keeps future changes cheap |
A ₹10 lakh application should carry a ₹1.5–2.5 lakh annual line. Skipping it does not save money; it converts maintenance into technical debt that you repay with interest at redesign time.
What moves you toward 15% vs 25%
- Integration count. Every third-party API you depend on is a change stream you don't control.
- Regulatory surface. GST, payments, and health data mean compliance updates on someone else's schedule.
- Release cadence. Products still evolving weekly need more perfective budget than stable internal tools.
- Stack choices. Boring, mainstream technology (see our startup stack guide) is dramatically cheaper to maintain than exotic frameworks.
Contract structures that work
- Retainer with hours pool — best for most: guaranteed response times, unused hours partially roll over.
- SLA-only + billed work — for stable systems: you pay for uptime guarantees, fixes billed separately.
- Product-team retainer — for growing products: a standing fraction of a team shipping improvements continuously.
Avoid pure pay-as-you-go for anything revenue-touching — the moment you need urgent help is exactly when unscheduled vendors are busy.
Questions to ask any maintenance provider
What is included vs billed? What are response-time commitments by severity? Who owns monitoring? What happens to unused hours? And critically — do they perform preventive work, or only react? Reactive-only maintenance is how systems rot on schedule.
Budgeting a new build? Our cost calculator shows the yearly maintenance figure alongside every estimate. For an existing system, ask us for a maintenance audit — we quote after we look, not before.
Frequently asked questions
How much does software maintenance cost per year?
The industry standard is 15–25% of the original build cost annually. A ₹10 lakh application should budget ₹1.5–2.5 lakh per year, covering bug fixes, security and dependency updates, small feature changes, and preventive work.
What decides whether maintenance costs 15% or 25%?
Integration count (every third-party API is a change stream you don't control), regulatory surface like GST and payments compliance, how actively the product is still evolving, and whether the stack uses boring mainstream technology or exotic frameworks.
What happens if I skip software maintenance?
Costs don't disappear — they convert into technical debt. Unpatched dependencies become security incidents, small deferred fixes compound, and the eventual 'redesign' bill is largely deferred maintenance repaid with interest.
What maintenance contract structure is best?
For most businesses, a monthly retainer with an hours pool and guaranteed response times. Pure pay-as-you-go is risky for revenue-touching systems — urgent needs arrive exactly when unscheduled vendors are busiest.