AI, data and processes
What does a custom business app really cost, and is there a cheaper alternative?
By the Long Lever team · 7 min read · Last checked 6 November 2026
The short answer
UK agencies typically quote around £10,000 to £25,000 for a simple first version and £25,000 to £60,000 for a production business app, with complex, integration-heavy systems costing more, plus monthly support retainers. For most internal tools, learning to build it yourselves with an AI app builder, with a few coached sessions, costs a fraction of that, often a few thousand pounds up front and modest monthly subscriptions.
What do agencies charge for a custom app?
Published UK pricing guides for 2026 put a simple first version at roughly £10,000 to £25,000, a production app with an admin area and back end at £25,000 to £60,000, and complex, regulated or integration-heavy systems at £80,000 to £120,000. Developer time is commonly charged at around £400 to £570 a day once testing and project management are included.
Those figures are for the build. They don't include what it costs to keep the app running and changing.
What are the running costs people forget?
- Support and maintenance retainers, often from around £1,000 a month.
- Hosting and third-party services, such as email, maps and storage.
- Every change request, charged at day rates, so the app gets harder to change as the business moves on.
- Per-user licences if the agency builds on its own platform.
- Lock-in: if the agency owns the code or the platform, moving away costs as much as starting again.
How do the options compare over three years?
An illustrative internal business app, such as a contract tracker with a client portal and monthly reporting:
| Off-the-shelf software | Agency build | Learn to build it yourselves | |
|---|---|---|---|
| Up-front cost | Low | £40,000 | £3,000 guidance package |
| Monthly cost | Per user, e.g. 25 users × £30 = £750 | £1,000 support retainer | About £100 in tool subscriptions |
| Three-year total | About £27,000 | About £76,000 | About £6,600, plus staff time |
| Fits your process? | You change to fit it | Yes, at first | Yes, and you keep it that way |
| Who can change it? | The vendor | The agency, at day rates | Your own team |
| Who owns it? | The vendor | Depends on the contract | You |
The do-it-yourself figure leaves out your team's time, which is real: expect several days spread over a few weeks. But that time also builds knowledge you keep.
What's the catch with building it yourselves?
There are three, and all are manageable. Someone has to understand the process well enough to describe it. Someone has to own the tool once it's built. And you need to set access and data rules properly from the start. That's where an experienced guide earns their fee: not by building it for you, but by making sure it's built on solid ground.
What does Long Lever charge?
We keep it simple and fixed. A first conversation is free. A discovery session is £500 for half a day, with a written one-page plan, deducted if you carry on. Build-with-you packages are typically £1,500 to £4,000, fixed and agreed up front, over 2 to 5 days. Or, for the right project, we'll take a share of proven savings at twelve months instead. There are no subscriptions to us, ever.
What this won't do
The agency prices here come from published UK guides and vary widely; your quotes may be higher or lower. Building it yourselves suits internal tools; it isn't the right answer for public apps at large scale, payment systems or software you plan to sell. If that's what you need, a good developer is worth the money, and we'll tell you so.
Questions people also ask
How much does it cost to build a business app in the UK?+
Published 2026 guides put a simple first version at about £10,000 to £25,000 and a production app at £25,000 to £60,000, with complex systems higher, plus ongoing support.
What are the ongoing costs of a custom app?+
Typically a support and maintenance retainer, often from around £1,000 a month, plus hosting, third-party services and day rates for any changes.
Is there a cheaper alternative to a custom app?+
For internal tools, yes: building it yourselves with an AI app builder, usually with some guidance, for a few thousand pounds up front and modest monthly subscriptions.
What does Long Lever charge?+
A free first conversation, a £500 fixed discovery session, and fixed build-with-you packages from £1,500 to £4,000. No subscriptions to us.
Sources
Facts and rates last checked 6 November 2026. We review every article at least every six months.
About the Long Lever team
Long Lever Partnerships is a collective of business owners and operators: people who have built, run and sold businesses, some with multi-million-pound turnovers, and people who have spent their careers in the field. We have no software to sell and no commission from any provider.
We guide, you build and own it.
Want to know where this fits in your business? The free discovery check takes a few minutes, and the first conversation costs nothing.