Ask five UK firms what a piece of bespoke software will cost and you'll get five numbers spread across an order of magnitude, plus one "book a discovery workshop to find out". None of that helps you budget. Most of the industry avoids publishing numbers because vagueness keeps the door open for a bigger quote later.
This article gives you the real ranges, explains what pushes a project from one band to the next, and tells you when bespoke software is the wrong answer entirely. By the end you should be able to look at your own problem and place it within a few thousand pounds.
The short answer
Honest UK ranges for bespoke software in 2026:
- A small internal tool (one job, a handful of screens, a few users: think "replace the spreadsheet the whole office fights over"): £3,000–£10,000
- A typical SMB system (multiple connected screens, user accounts, roles, reporting, integrations with a couple of your existing tools): £10,000–£30,000
- A customer-facing portal (your clients log in, see their own data, upload documents, get notified): £15,000–£40,000
- A full product build (something you'd sell, with billing, onboarding, and support baked in): £40,000–£100,000+
The first two bands cover most of what a small UK business actually needs. The jump between bands is rarely about the number of screens; it's about the number of people who can break it, the sensitivity of the data inside it, and how many other systems it has to talk to.
If someone quotes £50,000 for a tool that three staff will use to track jobs, ask what's in there. If someone quotes £1,500 for a customer portal, ask what's been left out, because something has.
Why the same brief gets wildly different quotes
Three things explain most of the spread:
- Who's building it. A freelancer, a UK studio, and an offshore agency have completely different cost bases. Offshore looks cheapest per hour and frequently costs the most per finished, working feature, because the hidden cost is the re-explaining, the time zones, and the rebuild when the first version misses the point.
- What "done" means. One quote covers code that runs on the developer's laptop. Another covers deployment, backups, error alerts, documentation, and a handover session. They are not the same product, and the cheaper one is only cheaper until the developer disappears.
- Day rates versus a fixed price. A day-rate engagement transfers all the risk to you: if it takes longer, you pay more, and the person deciding how long it takes is the person being paid by the day. A fixed price agreed in writing before work starts transfers the risk to the builder, which is where it belongs. We've written before about why hourly pricing is a red flag and the logic is identical for software.
What drives the price up
The honest cost drivers, in roughly the order they bite:
- User accounts and permissions. The moment different people need to see different things, you've added login, roles, password resets, and an admin screen. Necessary, but real scope.
- Integrations. Every existing system the software must talk to (your accounts package, your calendar, a supplier's API) is a separate piece of engineering with its own failure modes.
- Sensitive data. Medical, financial, or HR data brings encryption, access controls, audit trails, and UK GDPR documentation. Skipping this to save money is how small firms end up writing breach notifications.
- Customer-facing surfaces. Software your own staff use can be plain and forgiving. Software your customers touch has to look right, work on every phone, and never embarrass you. Polish costs.
- Migration from the old mess. If ten years of inconsistent spreadsheet data needs to become clean records in the new system, cleaning and importing it is often a mini-project of its own.
What keeps the price down
- A tight brief. "Track every job from enquiry to invoice, for four staff" is a brief. "Modernise our operations" is a fishing licence.
- Boring technology. You are not buying innovation, you're buying reliability. Proven, unglamorous tools ship faster and break less.
- Starting with one workflow. The best bespoke systems start as one working tool that solves the most painful job, then grow. Building everything at once multiplies the cost and delays the day anything works.
- Existing accounts and infrastructure. If the software can live on hosting you already pay for, or a managed arrangement, you skip a setup project.
The maths against off-the-shelf
Bespoke software competes with subscriptions, so do the comparison properly. Five staff on a £40-per-user-per-month SaaS tool is £2,400 a year, £12,000 over five years, for something that fits your process approximately and can raise prices whenever it likes. A £10,000 bespoke tool that fits exactly, with no per-seat licence, passes it inside five years and is yours outright.
That maths doesn't always favour building. If a mainstream tool fits your process well, buy it; we've set out when each side wins in custom software vs off-the-shelf SaaS. The short version: buy for solved problems (email, accounting, payroll), build when your process is the thing that makes you better than your competitors and no product matches it.
When bespoke software is the wrong answer
A responsible builder should talk you out of a build when:
- An off-the-shelf tool fits 90% of the need. Adapting your process slightly is cheaper than software that matches it perfectly.
- The real problem is a missing integration. If the tools you own just don't talk to each other, automation that connects them costs a fraction of replacing them.
- Nobody owns the process. Software freezes a process in code. If the process changes weekly, fix the process first.
- The budget only covers version one. Software needs a home: hosting, backups, small fixes. If there's nothing left for that, the tool will rot.
What a straight quote looks like
Whoever you talk to, a quote worth signing has four properties: a fixed number in writing before work starts, a scope you can read and understand, a named person who does the actual building, and clarity on what you own at the end. On that last point, insist on owning the code, the data, and the accounts it runs under. Some firms price the build low and make their money renting your own system back to you; the polite name for that is lock-in, and you'll meet it at the exact moment you try to leave.
That's how we work at Orchestrix: one fixed price agreed up front, everything yours to keep, and a straight "no" if we think you shouldn't build at all. If you've got a spreadsheet doing a job software should do, show us what's slowing you down and we'll put a real number on fixing it, in writing, before you commit to anything.