A small business application built in the UK typically costs from about £7,500, a customer portal or small mobile app from about £16,000 to £35,000, and a system used across a business £40,000 or more. The figure depends far more on how much the software has to do than on the technology it is built with.
Those ranges come from a simple estimating model, set out below, at a day rate of £600. You can change every input in our cost calculator and see the range for your own project.
Worked examples
Each row is the calculator’s result for a typical project at £600 a day, excluding VAT.
| Project | Days of work | Estimated cost |
|---|---|---|
| A spreadsheet replaced by a small web application | 16 | £7,500 to £12,500 |
| A connection between two systems | 10 | £5,000 to £8,000 |
| A small internal system with a few roles, linked to accounts | 25 | £12,000 to £19,500 |
| A small customer portal in your branding, linked to one system | 33 | £16,000 to £25,500 |
| A small mobile app in your branding, linked to one system | 43 | £20,500 to £33,500 |
| A medium internal system with reports, an audit trail and two or three integrations | 54 | £26,000 to £42,000 |
| A medium mobile app in your branding with two or three integrations | 78 | £37,500 to £61,000 |
| A large system used across the business | 88 | £42,000 to £68,500 |
These are estimates of market cost, not quotations. A day rate of £400 lowers every figure by a third, and £900 raises it by half.
What drives the cost
How much it does
This matters most. A system with ten screens and one main process is a different job from one with forty screens used by every department. Count the distinct things people need to do, and the number of screens follows.
Who uses it, and what each may see
If everyone sees and does the same things, permissions are simple. Once a manager can approve what a team member cannot, or a customer may see only their own records, every screen has to enforce those rules and every rule has to be tested.
What it connects to
Each connection to another system, such as your accounting package, a payment provider or a customer database, is a small project of its own. It needs access to the other system, an agreed way of handling failures and testing with real data.
Existing data
A system that starts empty is the cheapest case. Bringing across years of records from a spreadsheet or an old database means cleaning the data first, and the worse its condition, the longer that takes. This is the item buyers most often leave out.
Web or mobile
A web application that works well on a phone’s browser costs noticeably less than an app installed from the app stores, and suits most business uses. An installed app is worth the extra when it must work without a connection or use the phone’s hardware. Our article on native apps and web apps covers the choice.
Design
Standard, well-made components cost little. A custom visual design in your branding adds days, and is usually worth it for anything customers will see.
What the estimate leaves out
- Hosting. A monthly cost that depends on usage.
- Licences and third-party services. Payment providers, mapping, text messages and similar.
- Support after launch. Fixes, updates and changes are a separate maintenance arrangement.
- Your own time. Someone in the business has to answer questions, review progress and test the result.
Why quotes for the same project differ so much
Three quotes for one brief can differ by a factor of three. The usual reasons:
- They are pricing different things. One includes data migration and testing, another assumes you will do both.
- Day rates differ. A freelancer, a UK software company and a large consultancy charge very different rates for a day.
- Some are guesses. A figure produced without questions being asked is a guess, and the gap is paid for later.
Compare what each quote covers before comparing the totals. Our guide to fixed price and time and materials explains how the two pricing models shift the risk.
How to reduce the cost without cutting corners
- Build the smallest useful version first. Launch the one process that matters most and add the rest once people are using it.
- Use a web application unless you need the app stores.
- Clean the data yourself. Nobody knows it better, and it is the task that most often overruns.
- Use standard design components for anything internal.
- Decide quickly. Projects cost more when questions wait weeks for an answer.
Getting a figure you can rely on
An estimate tells you whether a project is affordable. A price you can hold a supplier to needs the scope agreed first: what the software does, what it connects to and how you will judge that it is finished.
We build to a fixed price once that scope is agreed, so an overrun is our cost and not yours. Start with the cost calculator to get a range, then tell us what you want built.