How much does a custom booking system cost in the UK?

By Brian Sinclair · 6 min read · Updated 5 August 2026

Most pages that rank for this question are written by agencies who want to sell you a discovery workshop. Here is the answer up front instead: for a single-location UK service business, a custom booking system built by me typically lands between £2,500 and £8,000, fixed price, agreed before anything starts.

That range is real. I built Glow, a booking platform for lash, brow and nail technicians that is live with paying customers, and I quote booking builds every week. The rest of this page explains what moves you up or down inside that range, and, just as importantly, when you should not buy a custom system at all.

What the price actually depends on

Booking systems all look the same from the front: a page with available times and a button. The cost lives in the rules underneath. When someone tells me their requirements, these are the things I am listening for:

  • Availability logic. One person with one diary is simple. Multiple staff with different rotas, treatments with different durations, and rooms or chairs as a constraint is where the real work is.
  • Money. Taking a card deposit at booking, holding it against no-shows, and getting the money into the right account (especially with multiple staff who each want paying) adds real complexity. This is Stripe Connect territory.
  • Client rules. Returning-client-only services, patch tests that gate certain treatments, consent forms, cancellation windows. Every rule your business runs on has to become code.
  • Reminders and messaging. SMS and email reminders are standard. Automated aftercare, review requests and rebooking prompts are more.
  • Migration. If you have years of appointments and client records in another system, getting them out and in cleanly takes real effort. One salon on Glow migrated over 16,000 historical appointments and 5,600 client records.

What the bands look like in practice

At the lower end, £2,500 to £4,000 gets a solid single-business system: public booking page, availability for a small team, deposits, reminders, and client records. Clean, reliable, yours.

From £4,000 to £8,000 you are adding the harder pieces: complex rota and resource logic, consent and compliance flows, multi-staff payment routing, reporting, or migrating a large history from your old system.

Beyond £8,000 you are usually not building a booking system for one business any more, you are building a platform for many businesses. That is a different conversation, and an honest developer will tell you so before you spend the money.

Smaller pieces of work, like adding online deposits to a system you already have, or an integration between your booking tool and your accounts, usually land between £500 and £1,500.

When you should not buy custom

If an off-the-shelf tool covers your rules and the fees do not sting, use it. I say this on the first call when it is true, because a custom build that should have been a £30-a-month subscription helps nobody.

Custom earns its money in two situations: when the fees scale painfully with your success (commission per booking, charges per new client), or when your business has rules that generic software cannot express, and your staff are burning hours working around it. If neither of those is biting you yet, wait.

Why fixed price matters

Every number on this page is fixed price, agreed in writing before work starts. Hourly billing on a booking system puts all the risk on you, because you cannot judge how long availability logic should take to build. I can, so I carry that risk instead. If I misjudge it, that is my problem, not your invoice.

Common questions

How much does a custom booking system cost in the UK?

For a single-location UK service business, typically £2,500 to £8,000 fixed price, depending on availability logic, deposits, client rules and any data migration. Smaller additions to an existing system usually run £500 to £1,500.

How long does a custom booking system take to build?

Most single-business booking builds ship in a matter of weeks, not months. The timeline is agreed alongside the fixed price before work starts, and the biggest variable is usually data migration from your old system.

Is a custom booking system worth it over Fresha, Treatwell or Acuity?

Only sometimes. If an off-the-shelf tool covers your rules and the fees are tolerable, use it. Custom is worth it when commission or per-client fees scale painfully with your growth, or when your business rules (patch tests, deposits, returning-client-only services) cannot be expressed in generic software.

Who owns the code when the build is done?

You do. You are paying for a system, not renting one. There is no lock-in: the code, the data and the accounts are yours.

What happens after launch?

Ongoing support retainers start from £150 a month, covering maintenance, small changes and fixes from the person who wrote the code, not a ticket queue.

Want a number for your build?

Fifteen minutes is enough. Tell me the problem, and I will tell you honestly whether custom software is the answer and roughly what it would cost.

Book a call

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