How much does it cost to build a mobile app in the UK?

Mobile app costs are hard to pin down because the phrase covers everything from a simple field-service tool to a consumer app with a million users. Here is how to work out which kind you are building, what the options cost relative to each other, and what to budget for after launch.

First question: do you need an app?

Be honest about this. An app makes sense when you need:

• Offline working (engineers on site with poor signal).
• Device features: camera for photos or barcodes, GPS, Bluetooth.
• Push notifications.
• A home-screen presence and app store discoverability.
• Performance beyond what a browser gives.

If the aim is "customers can log in and see their orders", a responsive web application does it without app store approval, downloads, or the cost of keeping two apps current. It can even be installed to the home screen as a progressive web app. Rule this out before committing to native.

The three ways to build

Native. Separate apps written in Swift (iOS) and Kotlin (Android). Best performance and the fullest access to device features. Twice the code, twice the testing, roughly twice the cost of one app.

Cross-platform. One codebase in Flutter or React Native that produces both apps. Near-native performance for most business and consumer apps, one team, one set of changes. This is what we recommend for the majority of projects.

Web app. Built once as a website designed for phones, optionally installable. No store process, instant updates, cheapest to build and maintain. Limited access to some device features.

Relative cost

If a cross-platform business app is the baseline, expect native to cost roughly one and a half to two times as much, and a web app somewhat less than the baseline. In absolute terms, business apps with a back end sit in the tens of thousands of pounds range in the UK market, with consumer apps involving rich design, many screens and high scale going well beyond. Our custom software cost guide explains what moves the number.

The half people forget: the back end

The app on the phone is the visible part. Behind it sits a server, a database, user accounts, an API the app talks to, and usually integrations with your existing systems. See what is an API. For most business apps the back end is at least as much work as the app, and it is what makes the app actually do anything.

What else goes into the price

• Design. Screens, flows and the polish users expect from an app.
• User accounts and security. Sign-in, password reset, permissions, data protection.
• Push notifications and the service behind them.
• Integrations with your ERP, CRM or accounts.
• Testing across devices, screen sizes and operating system versions.
• App store submission. Developer accounts, listings, screenshots, review process and the changes reviewers sometimes demand.

Reducing the cost

Start with an MVP: the one job the app must do, done well. Choose cross-platform unless you have a specific reason not to. Reuse an existing back end if you have one, for example an Odoo ERP with its API. Keep design consistent with platform conventions rather than inventing every control.

After launch

Apps need maintenance. Each year brings new operating system versions, new devices and occasionally new store requirements. Budget for regular maintenance releases, back-end hosting, and improvements driven by what users do. A support plan covers this; ask about it before the build starts. See who owns the code for what you should receive at the end.

We build cross-platform and native apps with the back ends behind them, and we will tell you if a web app would serve you better. Read about our custom software service or request a quote.

Frequently asked questions