“How much does an app cost?” is a fair question with an unsatisfying answer: anywhere from £5,000 to well over £250,000. That range is not evasion. An app is a category, not a product — in the same way that “a vehicle” covers both a moped and an articulated lorry.
What follows is what actually moves the number, so you can place your own project on the scale before you speak to anyone.
The five things that set the price
1. Number of platforms. iOS only, Android only, both, or web too. Cross-platform frameworks such as React Native and Flutter let one codebase serve iOS and Android, typically saving 30–40% versus two native builds — not 50%, because platform-specific work never fully disappears.
2. Backend complexity. An app that only displays content is cheap. An app with user accounts, a database, permissions, and business logic running on a server is a different animal. The backend is frequently more than half the cost, and it is invisible in a design mockup, which is why it surprises people.
3. Integrations. Every external system — payments, maps, messaging, CRM, accounting — adds work. Well-documented modern APIs are quick; legacy systems are not.
4. Design ambition. A clean interface using platform-standard components is efficient. Bespoke animation, custom illustration, and a distinctive design language cost real money and real time.
5. Compliance and data sensitivity. Handling health records, financial data, or children's data brings requirements — encryption at rest, audit logging, data residency, penetration testing — that can add 20–40% to a build.
What each budget tier buys
| Budget | What is realistic | Timeline |
|---|---|---|
| £5,000–£15,000 | Simple single-purpose app, standard components, minimal backend, one platform or cross-platform. Or a validation MVP. | 4–8 weeks |
| £15,000–£40,000 | Real product: accounts, database, a few integrations, custom design, cross-platform, basic admin. | 2–4 months |
| £40,000–£100,000 | Complex app: multiple user types, payments, real-time features, substantial backend, thorough testing. | 4–8 months |
| £100,000+ | Platform-scale: high traffic, regulated data, native on both platforms, heavy integrations, dedicated team. | 8 months+ |
You can model your own figure with our software project cost estimator, which breaks the number down by type, complexity, and team size.
Why UK quotes differ so much
The same brief can return £18,000 from one supplier and £:70,000 from another. The usual causes, in order of frequency:
- Different scope assumptions. One quote includes design, testing, deployment, and app store submission; the other includes development only.
- Different day rates. UK agency rates commonly run £400–£900/day; offshore teams £100–£300/day. Rate is not quality, but it does change how much scope your budget buys.
- Optimism. Some quotes are simply wrong — and a quote that is too low usually resurfaces as change requests halfway through.
The practical defence is to give every supplier an identical written brief and ask each to state explicitly what is excluded. Comparing exclusions is far more revealing than comparing totals.
The costs nobody puts in the quote
Build cost is not total cost. Budget annually for:
| Ongoing cost | Typical annual figure |
|---|---|
| Hosting and infrastructure | £300–£6,000 |
| Apple Developer + Google Play | £80–£120 |
| Third-party services (maps, SMS, email, payments) | £200–£5,000 |
| Maintenance and OS-update compatibility | 15–20% of build cost |
| Support and bug fixes | £1,000–£10,000 |
That maintenance figure is the one people miss. iOS and Android ship major releases annually; an app left untouched for two years will break. Treat 15–20% of build cost per year as the cost of the app continuing to work, not as optional.
Where you can genuinely save
Cut scope, not quality. Halving the feature list saves real money. Halving the testing budget costs more later.
Start with one platform. Launch where your users actually are, validate, then expand. Analytics on your existing site will tell you the split.
Consider a web app first. If you do not need camera, offline mode, push notifications, or app-store presence, a responsive web app is cheaper to build and far cheaper to update — no review process.
Use standard components. Platform-native UI patterns are free, familiar to users, and accessible by default.
Own your code and accounts. Insist the repository, hosting, and store accounts are in your name. It costs nothing at the start and saves thousands if you ever change supplier.
How to read an estimate
A trustworthy estimate names its assumptions, breaks cost down by phase, states what is excluded, and identifies the riskiest unknowns. A weak one is a single number with a timeline. Ask any supplier three questions: what is the riskiest part of this build, what would make it cost more, and what are you assuming that I have not told you? The quality of those answers predicts the project better than the price does.