How much does custom software cost in the UK?

The honest answer is “it depends”, which is annoying, so here’s what it depends on. We’ve looked at what UK agencies publish and we’ll explain the factors that move a number up or down. One caution: nearly all published figures come from companies selling software development, so treat them as indicative. There’s no independent UK price survey we’d point you to.

What published UK figures say

Agency guides written for 2026 commonly put a first production version somewhere between about £10,000 and £150,000, with large enterprise platforms going much higher. For example, Magora and Softomate Solutions both publish UK guides in this general territory, and others quote £500,000 or more for large systems. The sources don’t agree with each other exactly, as you’d expect.

These are broad bands drawn from those published guides, not a Techpedia price list. We quote against an agreed scope.

What really drives the price

Software cost is mostly people’s time, so anything that adds time adds cost. The biggest drivers tend to be:

• Number of workflows and user roles. Each role multiplies screens, permissions and test cases.
• Integrations. Connecting to well-documented modern APIs is fairly straightforward. Connecting to an old system with no documentation can take longer than the rest of the feature.
• Data migration. Years of inconsistent spreadsheet data rarely imports cleanly.
• Regulation and security. Audit trails, access controls and external assessments all add work, particularly in health and finance.
• Design ambition. A functional internal tool costs much less than a polished consumer product.
• Uncertainty. The less that’s known, the more contingency a supplier needs to allow.
• Who does it and where. Rates vary widely between a London senior team and an offshore one, as does how much management each requires.

Costs people forget

The build isn’t the total cost of owning software. Budget for:

• Maintenance. Security updates, dependency upgrades and fixes. Agency guides often suggest about 15 to 25 per cent of build cost per year. A simple system may need less, and an actively developed one more.
• Hosting and services. Servers, backups, monitoring, email delivery and any third-party APIs. AI features add usage costs that rise with use.
• Your own team’s time. Someone needs to answer questions, test releases and make decisions. This is the cost most often missed.
• Training and rollout. Time for people to learn the system, and often a period of running old and new together.
• Security testing. Independent penetration tests, if your clients or regulators expect them.

How to keep the cost down

• Cut the first release ruthlessly. Ship one complete workflow. Plenty of the features on your list will turn out not to matter once people start using it.
• Use existing services. Don’t build your own payments, email delivery or login from scratch.
• Be available. Quick decisions from one empowered person save more money than most technical choices.
• Clean your data early. Tidy spreadsheets before migration work begins.
• Consider whether you need it at all. Our custom versus off-the-shelf guide might save you the entire budget.

How to judge a quote

A credible estimate lists its assumptions and what’s excluded, and it should come after a proper conversation rather than from a form. If one quote is much lower than the rest, compare what each actually includes, especially testing, project management, deployment and support. Be wary of precise fixed prices given before anyone has seen your systems. Paying for a short discovery phase before a larger commitment usually gives you a much more dependable number, along with useful documentation even if you decide not to carry on.

If you’d like a rough idea for your own project, send us a short description. It’s helpful to include your budget range so we can tell you what’s realistic.