Software Maintenance Cost After Go-Live: Annual Budget
Software maintenance cost is usually 15–20% of the original build price every year, and it can reach 20–30% for large, heavily integrated systems. On a ₹10 lakh application that is ₹1.5–2 lakh a year, before GST, for as long as you run the software.
This guide splits that figure into what keeps the system running and what changes it, shows the rupee range by build size, and lists what a maintenance contract should say before you sign it.
Key takeaways
- The long-standing rule of thumb is 15–20% of build cost per year (Savi); other vendors quote 15–25% (Space-O).
- A 2026 benchmark of 24 SaaS products put the budget at 18–30% a year while a product is still evolving, and 10–16% for a quiet internal app (Wavect).
- Roughly 60% of a system's total cost is spent after launch, not on the build (Pegotec).
- Large, heavily integrated systems can need 20–30% of build cost a year (Intigate).
How much does software maintenance cost per year?
Plan on 15–20% of the build cost per year as the baseline, and move up to 25–30% if the software is large, changes often or depends on many outside systems. Move down toward 10–16% only for a stable internal tool that nobody is asking to change.
Here is what that means in rupees. These figures are our arithmetic on the percentages above, not quotes, and they exclude 18% GST.
| Build cost | Quiet internal tool (10–16%) | Typical business app (15–20%) | Evolving or integrated (20–30%) |
|---|---|---|---|
| ₹5 lakh | ₹0.5–0.8 lakh | ₹0.75–1 lakh | ₹1–1.5 lakh |
| ₹10 lakh | ₹1–1.6 lakh | ₹1.5–2 lakh | ₹2–3 lakh |
| ₹25 lakh | ₹2.5–4 lakh | ₹3.75–5 lakh | ₹5–7.5 lakh |
The percentages come mostly from vendor blogs, not peer-reviewed studies, so treat them as a planning range. Your own number should come from a written scope, which the later sections help you build.
What does annual software maintenance actually cover?
Maintenance covers four kinds of work: fixing faults, adapting to a changed environment, adding or refining features, and cleaning up the code so future changes stay cheap. The categories are standard in software engineering (University of Edinburgh).
| Type | What it means | Example | Rough share of effort* |
|---|---|---|---|
| Corrective | Fix faults users report | A report shows the wrong total | ~20% |
| Adaptive | Keep up with a changed environment | New OS, browser, payment API or GST rule | ~25% |
| Perfective | Improve or extend what exists | A new report, a changed workflow | ~50% |
| Preventive | Make the code easier to change | Refactoring, documentation, upgrades | 3–5% |
*From classic Lientz and Swanson studies as summarised in course notes (JMU). They are decades old and categories are used inconsistently, so read them as proportions, not promises.
The useful reading is the one most guides skip: only about 20% of the work is fixing bugs. Most of the money goes on change.
Why split the budget into "run" and "change"?
Because the two behave differently, and one blended percentage hides which one you are overspending. "Run" is the work that keeps the software alive; "change" is the work you choose to add.
- Run covers hosting and monitoring, backups, security patches, certificate and licence renewals, bug fixes and keeping up with outside changes such as a payment gateway update or a new GST rule. You cannot skip it. It is close to fixed from year to year.
- Change covers new reports, new screens, new integrations and workflow changes. It is discretionary and moves with your business.
A sensible way to budget is to fund "run" as a fixed annual contract and keep "change" as a separate pool of hours you can spend or save. Owners who buy one big percentage tend to find that new feature requests eat the whole retainer and nobody is left to apply security patches.
What does an annual maintenance contract (AMC) include?
An AMC is a yearly contract in which the vendor agrees to keep your software working for a fee. Indian vendors typically offer it as an annual contract, a monthly retainer or hourly support, and the line items that vary most are the ones that cause disputes.
Check these before you sign:
- Scope of fixes. Are all bugs covered, or only bugs in code the vendor wrote?
- Response times. Look for a written service level (SLA): how fast they reply and how fast they fix, by severity, and during which hours.
- Hosting and infrastructure. Is hosting inside the fee or billed separately? Who renews the domain, SSL and cloud account, and in whose name?
- Security updates. Are framework and library upgrades included, or quoted per upgrade?
- Third-party services. Payment gateways, SMS, maps and AI APIs change their rules and prices. Who absorbs the effort?
- Change hours. How many hours of new work are included, and what is the hourly rate beyond that?
- Ownership. You should hold the source code, the credentials and the documentation, so you can move to another vendor.
- GST. Quotes are usually before 18% GST. Confirm which one you are comparing.
What makes maintenance cost rise over time?
Maintenance cost rises when the code gets harder to change and when the world around it keeps moving. One benchmark measured medians of 24%, 21% and 26% of build cost in years one to three, so costs do not fall in a straight line (Wavect).
The usual causes:
- Technical debt. Shortcuts taken to hit a launch date make every later change slower and riskier.
- Thin documentation. A new developer has to rediscover how things work before touching them.
- Integrations. Every connected system is another thing that can change without asking you.
- Growth. More users and more data mean more monitoring, tuning and support.
- New capabilities. If you plan to add AI features later, budget for model usage and monitoring as well; our AI feature development cost guide covers that.
How should you budget maintenance in year one?
Add it to the build price when you compare quotes, not after. A cheap build with high upkeep is often dearer over three years than a better-built system with low upkeep. Roughly 60% of the lifetime cost sits after launch, so that is where the comparison belongs (Pegotec).
A simple method:
- Take the build quote and multiply by 15–20% for your "run" baseline.
- Add GST at 18%.
- Add a separate pool of change hours: start with the number of changes you already know you want in the first year.
- Ask each vendor to price the same scope, and compare three-year totals.
Our custom software development cost guide shows how maintenance sits alongside GST, hosting and integrations in a first-year total, and the custom vs off-the-shelf comparison covers when per-user fees beat upkeep. If your system is an ERP, see ERP implementation cost for the support line that follows go-live.
What we've seen at DECK IT
At DECK IT in Ahmedabad, we build custom software and business systems, and the question that follows a handover is nearly always the same: "what do we pay from here?" Our advice is to settle it before the build starts, because the maintenance terms shape how the system is built: documented, tested and hosted in an account you own.
The trade-off we point out is between a fixed retainer and a pool of hours. A retainer gives you predictable cost and covers the "run" work. A pool of hours gives you flexibility for "change". Most owners are better served by both, kept as separate lines so a feature request never silently consumes the security budget. If you are planning a new build, our custom software and web development team scopes support alongside the build.
Frequently asked questions
How much does software maintenance cost per year?
Plan on 15–20% of the original build cost per year as a baseline. Large or heavily integrated systems can need 20–30%, and a quiet internal tool may sit nearer 10–16%. On a ₹10 lakh build that is roughly ₹1.5–2 lakh a year before GST.
Is 20% a year normal for software maintenance?
Yes, 20% sits at the top of the common 15–20% rule of thumb and inside the 15–25% some vendors quote. It is reasonable for a business application that still changes. If you are quoted well above 30% for a stable system, ask for the scope line by line.
What does an annual maintenance contract for software cover?
It normally covers bug fixes, security updates and support within an agreed response time. Hosting, third-party service changes and new features are often priced separately, so confirm each in writing. The contract should also say who holds the source code and credentials.
Does maintenance include new features?
Usually not, or only a limited number of hours. Classic studies suggest that about half of maintenance effort goes on improving and extending software rather than fixing it. Budget a separate pool of change hours instead of expecting the retainer to absorb them.
What happens if I stop paying for maintenance?
The software keeps running until something around it changes, such as a browser update, a security flaw or a gateway rule. Then faults pile up with nobody responsible. Stopping is workable for a short time on a stable tool, but it is a risk for anything that handles money or customer data.
Can another vendor maintain software I did not buy from them?
Yes, if you hold the source code, the credentials and decent documentation. Without them, you are locked in. Ask for all three at handover, whatever the maintenance arrangement.
Conclusion
Budget 15–20% of the build price every year as a baseline, add GST, and keep "run" and "change" as separate lines. Then compare vendors on three-year totals, not on the build price alone.
If you want a maintenance figure for a specific system, send us a short brief and we'll scope the support terms alongside the build.