Edi Javier
Founders & MVPsSeptember 28, 2026·8 min read

What Does Custom Software Really Cost a UK Small Business?

You ask three people for a quote on the same thing. One says £900. One says £4,000. One says £12,000. Nobody's lying — they're just quoting different things. Here's what actually moves the price.

Edi Javier
Edi Javier
Software Engineer
What Does Custom Software Really Cost a UK Small Business?

You ask three people for a quote on the same thing. One says £900. One says £4,000. One says £12,000. Nobody's lying, and nobody's necessarily ripping you off. They're just quoting different things, and nobody stops to explain the difference.

So let's do it properly. Below you'll find what UK small businesses typically pay for the most common projects, why the prices are so far apart, and how to decide if a project is worth it for your business. I'm a freelance software engineer based in London, so I'll also be upfront about where a freelancer fits and where one doesn't.

A quick note on the numbers: they come from UK pricing guides published in 2026. Many are written by people selling these services — me included, in a way — and they don't always agree with each other. Treat them as a map of the market, not a price list.

1. A professional website

This is the most familiar starting point. Most small businesses should budget between £1,000 and £3,000 for a professional, lead-generating website. A freelance developer or designer building on WordPress, Webflow or Shopify will typically deliver a solid small business site for £800 to £3,500, while a UK agency usually charges £2,500 to £10,000 for a standard small business site.

The gap is mostly about what comes with it: strategy, copywriting, branding, account managers. A freelancer gives you one person's judgement and direct communication, with no account management layer in between. Think of: a therapist, a salon, a local trades business that needs to look credible and be found online.

2. A website with bookings or a client system

This is where prices start to spread. A freelancer building a site with custom functionality like booking systems typically charges £1,000 to £3,000. For something built around how your business actually works rather than an off-the-shelf plugin, expect £5,000 to £12,000.

I worked with a wellbeing business that was doing everything in person, with no website and no system. They didn't know what they needed or where to start. We ended up with one place to manage clients and appointments, and a site people could actually find.

3. Automation and AI

This one has the widest range, so read it slowly. Simple workflows start from around £500. Multi-step builds typically cost £3,000 to £10,000. An AI agent — for lead qualification, support triage or document processing — runs £2,400 to £5,000 with a freelance developer, versus £5,000 to £12,000 with an agency. Bespoke AI systems start around £10,000, and a custom single-workflow automation can reach £8,000 to £25,000.

The reason for the spread is simple: the price scales with the number of systems you're connecting and how messy your data is, not with the size of your company.

A real example: a cleaning company with 800+ workers was receiving reports, absences and shift hours through WhatsApp, and processing everything by hand. Workers keep using WhatsApp — an AI reads each message, and the records update automatically. The team cut around 40% of its manual operational tasks. A project like that lives at the bigger end of this range. A simple lead-reply automation lives at the small end. Same word, "automation", very different work.

4. A custom web app or internal tool

When no off-the-shelf tool fits, you're in custom territory. Custom web apps start at around £10,000. A feature-rich app typically costs £15,000 to £50,000. Bespoke web platforms can go from £15,000 to £75,000+. This is a real investment — and often not the right first step.

5. Got an idea for a product? Don't start at the top

If you're an early-stage founder, spending £30,000 to test an idea is rarely the smart move. A no-code MVP costs around £2,000 to £10,000, and a validation prototype runs £5,000 to £15,000. Production-ready MVPs come later — £15,000 to £35,000 — once you know people want it. The goal isn't to build the biggest thing. It's to find out cheaply whether the idea works.

Why the same job can cost £500 or £25,000

Three things move the price more than anything else:

  • How many systems need to talk to each other. A form that emails you is cheap. A system that talks to your CRM, your accounting tool and WhatsApp is not.
  • How messy your data is. Clean records are fast to work with. Ten years of spreadsheets with hidden formulas take longer.
  • What "done" means. A quick prototype and a production-ready tool are different products with the same name.

Price vs payback: the number that matters more

For a small business, the question isn't "is this cheap?" but "does it pay for itself?"

The admin tool. An employee on £28,000 costs roughly £18 to £22 an hour once employer NI, pension and overheads are counted. If a workflow eats 7 hours a week, that's about £6,720 a year, every year. A £5,000 build costing £100 a month to run pays for itself in about ten months.

The lead-reply automation. For a UK small business, a £1,500 build with about £40 a month running costs was estimated to save around £600 a month at £30 an hour of opportunity cost.

These examples come from vendors, so your numbers will differ. But the method works: hours saved × cost per hour, minus monthly running cost. Try it with your own numbers before you ask anyone for a quote.

The costs after launch

Almost nobody mentions these upfront, so ask:

  • Monthly support: typically £200 to £800, retainers £300 to £1,500 a month for specialist help.
  • Tool subscriptions (Zapier, Make and similar): £20 to £480 a month, depending on volume.
  • Hosting for a custom automation on its own infrastructure: often £50 to £100 a month.
  • A basic website: an extra £100 to £300 a year on top of the build.

Freelancer or agency? An honest take

Freelance developers typically bill £250 to £500 a day. That gets you direct communication with no account management overhead. The honest downside: single-person dependency and no integrated QA, design or project management. It's a real trade-off — which is why how the engagement is structured matters (see below).

Five questions to ask before you say yes

  • What exactly is included? Ask for a list, not just a total.
  • What isn't? Design, testing, hosting, revisions, training.
  • What could delay it? A good developer names the risks.
  • Who owns the code, the accounts and the domain at the end?
  • What happens after launch, and what does it cost per month?

If two quotes answer all five, you're comparing like with like. If one can't answer, you've found your answer.

How I work

I don't start with code. I start with your business.

1. I get to know how you actually work. Before I propose anything, I take the time to dig into the problem, your company and what a normal day looks like. The goal is to find the real pain points, not just the ones that are easy to describe.

2. I work out what's worth fixing. Not every problem needs software. I look at which ones can be automated or improved, weigh how much impact each would have, and prioritise. That way the effort goes where it matters most.

3. We shape the plan together, before any code. Based on that, I put a plan together and go back and forth with you to refine it. It speeds things up, and stays open to iteration — if something changes along the way, the plan can change with it.

4. You're never locked in to me. Everything I build is documented, and the code, hosting and accounts are set up in your name from day one. If I'm ever unavailable, another developer can pick it up without starting from scratch.

Not sure where your project fits?

Send me a short description of what's slowing your business down, or the idea you have. I'll tell you honestly which of these buckets it falls into, roughly what it would cost, and whether it's even worth building. No pitch, no pressure.