Understanding Custom Software Maintenance Costs
Custom software needs ongoing care: bug fixes, security patches, dependency updates. Budget 15-20% of initial build cost annually. This guide covers typical costs, what's included, what's extra, and how to structure a maintenance agreement.
Table of Contents
Typical Maintenance Costs
$2,000 - $10,000/month depending on complexity. Simple internal tools: $2-4K/month. Complex systems with integrations: $6-10K/month. Rule of thumb: 15-20% of initial build cost annually. A $50K project = ~$7.5-10K/year maintenance.
Retainer vs. ad-hoc: Retainer (monthly) gives you priority support and a set number of hours. Ad-hoc is pay-as-you-go — good if usage is sporadic. Most clients prefer retainer for predictability.
What's Included
- Bug fixes — Defects, crashes, data issues. Included in retainer up to a reasonable cap.
- Security updates — Patches for dependencies, libraries, frameworks. Critical for staying secure.
- Dependency upgrades — Keeping Node, React, database drivers, etc. up to date. Prevents technical debt.
- Minor feature tweaks — Small UI changes, config updates, report adjustments. Scope defined in the agreement.
- Monitoring & support — Uptime checks, error alerts, response to incidents. Often included or add-on.
What's Extra
Major new features, new integrations, or significant redesigns are scoped and quoted separately. They're not "maintenance" — they're new development. Treat them like a new project: Discovery, quote, build.
Hosting and infrastructure (AWS, Vercel, etc.) are usually separate. You pay the cloud provider directly or we include it in a bundled fee. Clarify in the agreement.
How to Budget
Plan for 15-20% of build cost per year. Year 1 might be higher (post-launch stabilization). Years 2+ often settle at 15%. If you're adding features regularly, budget 20-25%. See our ROI guide to factor maintenance into your payback calculation.
Frequently Asked Questions
Can we maintain it ourselves?
Yes, if you have in-house developers. You own the code. We hand off documentation and runbooks. Many clients start with us for maintenance, then bring it in-house as they scale.
What if we skip maintenance?
Risky. Dependencies get outdated, security vulnerabilities accumulate, and the system becomes harder to change. Budget for at least minimal maintenance (security patches, critical bugs).
Explore Further
Need Maintenance Support?
Retainer or ad-hoc. We maintain systems we built and systems built by others.
Get in Touch