What software really costs after launch: a maintenance budget guide

Consulting · 6 min read

What software really costs after launch: a maintenance budget guide

FM
Farheen Mirajkar
Accountant · September 2026

The launch invoice is the number everyone negotiates. The numbers after it are the ones nobody budgets — and then year two arrives with surprises. As the person who watches these budgets for a living, let me lay out what custom software actually costs to own, so the total is a plan instead of a shock.

The four buckets of after-launch cost

Infrastructure — hosting, databases, backups, domains, certificates. Predictable, usually modest, and it scales with usage. Keeping the lights on — security patches, framework and OS updates, monitoring, the occasional bug that surfaces in month nine. Keeping up with the world — the accounting system changes its API, a new phone OS ships, a browser deprecates something; your software doesn’t live alone. Getting better — the features your team asks for once they’ve lived in the system, which is where real ROI compounds.

A rule of thumb you can actually use

Across the industry — and across our own projects — a sensible planning figure for the first three buckets is 15–20% of the build cost per year. Bucket four is a choice, not a tax: some clients budget a small enhancement release each quarter, others save requests for an annual batch. What matters is that it’s a decision made in the budget, not a scramble made in an emergency.

Why “no maintenance” quotes cost more

Software that skips the middle buckets doesn’t get cheaper — it gets brittle. Unpatched dependencies become security incidents; ignored API changes become sudden outages on the day the vendor flips the switch. The most expensive maintenance model is the one where nothing is maintained until something breaks in production, because emergency work is always priced by urgency.

Plan 15–20% of build cost per year to keep software healthy, and treat improvements as a separate, deliberate line. If a vendor’s proposal is silent on year two, that’s your question to ask.

How to compare vendors on the ongoing number

Ask three things: what’s included in support (and what’s billed extra), how are releases and regression testing handled after launch, and what happens if we pause — do we own the code and can another team pick it up? At Astotek the answers are: defined support with periodic releases, the same testing discipline as during the build, and yes — the code is yours. Compare answers, not just hourly rates; the cheap rate with vague answers is the expensive one.

Want the whole number up front?

We quote year two with year one. Ask us to show you.

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