Search for “custom software vs off-the-shelf” this autumn and the UK results are almost all agency guides, each with its own break-even figure. One puts the tipping point at around 30 to 40 users over five years. Another says custom software pays back in roughly two and a half years once your user count grows or your process drifts from the standard. A third finds that, for a 40-user business, a specialist SaaS subscription and a custom build often land in the same five-year range.
These are agency sources with a reason to favour custom builds, so treat the numbers as directional. But the figures they quote are consistent enough to be useful:
- Custom build: roughly £10,000 to £25,000 for an MVP, £30,000 to £90,000 for a first production release, and from £80,000 for enterprise-grade platforms. Delivery typically takes four to eight months.
- Off-the-shelf SaaS: about £25 to £60 per user per month, live in six to twelve weeks.
- The hidden lines: data migration, integrations and training are claimed to add 25 to 35 per cent to a SaaS rollout (a secondhand figure, so check it against your own quotes). On the custom side, ongoing hosting, support and change are estimated at 15 to 20 per cent of the build cost every year.
What it means in plain English
The break-even is not really about headcount. It is about how far your process sits from the standard one. If your workflow is conventional and your team is small, SaaS wins and you should not build anything. If you are paying for a SaaS tool and then running spreadsheets, manual re-keying and workarounds around it, you are already paying for custom software. You are just paying in staff time.
A quick test: list the three things your business does differently from competitors. If your current tool cannot do any of them without a workaround, price a custom alternative. If it handles all three, stay put.
So what
Ask any supplier to model five years, not twelve months, and to include maintenance and the cost of the workarounds you pay for today. AI-assisted delivery is also narrowing the build-cost side of the comparison, which is moving the break-even point toward smaller teams than before. If you want a straight view on which side of the line your project falls, see our custom software development service or start a project.