Table of Contents
- How much does mobile app development cost in the UK in 2026?
- Where your app budget actually goes
- What drives up mobile app development cost in the UK?
- Native or cross-platform: which build costs less?
- How much does an MVP app cost in the UK?
- The costs nobody puts in the quote
- How to hit your budget without gutting the app
- What a fair quote from a London studio looks like
- Frequently Asked Questions
- What your app should actually cost
Quick answer: Foundry 5 puts real numbers on mobile app development cost in the UK, where most 2026 builds land between £30,000 and £150,000. Scope sets that figure, not hype. With the UK median developer day rate at £504 (ITJobsWatch, 2025), a 60 day build is roughly £30,000 in engineering alone, before design, testing, and backend.
Ask five UK studios what your app will cost and you can walk away with five numbers that disagree by a factor of ten. One quotes £18,000. Another quotes £180,000. Same brief, same feature list, same two platform launch. That spread is the real problem with mobile app development cost in the UK: the number feels arbitrary, so founders either overpay out of caution or underpay and watch the build stall at 70% done.
The number is not arbitrary: it is arithmetic wearing a disguise. Every honest quote traces back to a day rate, a feature count, and a set of decisions you can actually control. Once you can see those levers, a £180,000 quote and an £18,000 quote stop looking like opinions and start looking like two very different products, priced on scope rather than on guesswork.
mobile app development London sits at the pricier end of the UK market, so London founders feel this spread most. The drivers below apply wherever you build.
This guide does the thing most pricing pages avoid: it shows the math. Where the money goes. What inflates a quote. What an MVP really costs. And how to hit a fixed budget without shipping something broken.
How much does mobile app development cost in the UK in 2026?
Foundry 5 sees mobile app development cost in the UK cluster in three bands in 2026: roughly £30,000 to £60,000 for a lean MVP, £60,000 to £120,000 for a standard cross platform app, and £120,000 upward for complex or AI enabled products. The band you land in tracks feature scope and platform count, not your postcode.
The UK median software developer day rate is £504 in the six months to April 2025, and that single figure explains most of the range. A build is mostly people time. Multiply a day rate by the number of build days and you have the engineering line before anyone mentions design or testing.
Consider the arithmetic. A focused MVP takes a small team roughly 55 to 70 working days across engineering. At a £504 median rate, that is £28,000 to £35,000 in front line development alone. Add design, quality assurance, and project management and the all in figure lands near the bottom of that first band. Nothing about it is mysterious.
The best way to read any quote is to reverse it into days. If a studio wants £120,000, ask how many build days that buys and who is on the team. A fair quote survives that question. A padded one does not.
Where your app budget actually goes
Most of your app budget goes to engineering and testing, not to the flashy screens founders fixate on. In a typical UK build, front end and back end development absorb roughly half the cost, design takes 15% to 20%, and quality assurance plus project management take another quarter between them. Design is the smallest line that founders argue about the most.
Picture a £90,000 cross platform build. The invoice is not one number: it is six smaller numbers stacked together, each tied to a distinct block of work. When a quote hides those blocks, you cannot tell whether you are paying for senior engineers rather than an agency’s office rent. The table below breaks a standard build into its real components.
| Phase | Share of budget | What you are paying for |
| Discovery and design | 15% to 20% | User flows, wireframes, UI, clickable prototype |
| Front end engineering | 25% to 30% | The screens, navigation, and device behaviour users touch |
| Back end and API | 20% to 25% | Servers, database, auth, and the API the app talks to |
| Quality assurance | 10% to 15% | Real device testing, bug fixing, release hardening |
| Project management | 10% to 15% | Planning, sprints, communication, keeping scope honest |
| Contingency | about 10% | The unknowns every real build meets after week three |
Read that table once and quotes stop being intimidating. A studio charging £90,000 with no design phase and no contingency is not cheaper: it has simply moved those costs to month four, when the bugs arrive and the rework begins. The backbone of the whole thing is the server layer and a mobile-ready API that holds up under real traffic. Skimp there and every screen you paid for inherits the weakness.
Want your quote broken into real numbers? If you are staring at estimates that disagree by a factor of ten, a short call turns the guesswork into a costed plan. Book a free 30-minute discovery call with Foundry 5 No pitch deck, no commitment, just the math behind your build.
What drives up mobile app development cost in the UK?
Four levers drive the cost of a mobile app: feature scope, platform count, design depth, and backend complexity. Feature scope is the heaviest by far. Every screen, every state, and every integration adds engineering days, and days are the currency the whole quote is priced in. Trim the feature list and the number moves more than any discount ever will.
Feature scope and integrations
A login screen is cheap. A login screen with social sign in, biometric unlock, password recovery, and account merging is four features wearing one label. This is where quotes quietly balloon: founders describe an app in ten sentences that hides forty features. Payments, live chat, maps, notifications, and offline mode each carry their own build and test cost.
Adding AI or LLM features is the newest cost driver, and the most misjudged. A chatbot or a recommendation engine is not a weekend add on: it needs data plumbing, evaluation, and guardrails, which is real engineering time on top of the app itself.
Platforms and design depth
Two platforms cost more than one, but rarely double. Design depth is the subtler lever: a template driven interface is fast, while custom animation and a bespoke design system add polish and days in equal measure. Ask whether that polish earns its cost on version one. Often it does not. Sometimes it is the whole product.
The pattern repeats on every build: teams discover the hard way that the cheap sounding feature carried the expensive backend. Scope is not the enemy. Unexamined scope is.
Native or cross-platform: which build costs less?
Cross platform usually costs less than native because one codebase serves both iOS and Android rather than two. A React Native or Flutter build can cut front end effort by 30% to 40% versus writing each platform separately. Native wins on raw performance and deep hardware access, but most business apps never touch the ceiling that justifies paying twice.
Here is the honest concession: native is not obsolete. A high frame rate game, a camera heavy product, or an app that leans on the newest OS features will run better and age better when built natively. That is a real exception. It is also a narrow one. For a marketplace, a booking tool, a fintech dashboard, or a community app, cross platform delivers the same user experience for meaningfully less money.
Deciding which mobile framework to choose comes down to one question: does your app live or die on a capability only native can deliver? If the answer is no, cross platform is not a compromise. It is the sensible default.
Watch for a studio that only builds native and frames cross platform as cheap. That is not technical judgement. That is a business model defending its day rate.
How much does an MVP app cost in the UK?
An MVP app typically costs £30,000 to £60,000 with a studio like Foundry 5, the lowest tier of mobile app development cost in the UK. An MVP is not a cheap version of the full app. It is the smallest build that proves people want the thing before you spend the other £100,000 finding out.
The full breakdown of how much an MVP costs in the UK comes down to a hard question every founder avoids: which three features prove the idea, and which twenty are you adding out of fear? Answer it and the MVP price sets itself.
Consider a London founder with a £120,000 budget and a 25 feature vision. Spend it all on version one and you are betting the entire runway on assumptions no user has tested. Spend £45,000 on a five feature MVP rather than the full vision and you keep £75,000 to react to what real users actually do. One path is a gamble. The other is an experiment with a budget. The MVP is the cheapest insurance policy in software. Skip it and you pay the premium anyway, later, in rework.
Already know the three features that matter? Start a scoping conversation with Foundry 5, or keep reading for the costs no quote mentions.
The costs nobody puts in the quote
The build price is not the total cost of owning an app. Plan for ongoing costs of roughly 15% to 20% of the original build each year for maintenance, plus app store fees, server bills, and the price of every change you request after launch. An app is infrastructure, not a painting: it needs upkeep the moment it goes live.
Maintenance, fees, and servers
Operating systems update twice a year, and an app that ignores them breaks. Apple charges $99 a year for a developer account and Google charges a one time $25. Cloud hosting scales with your users, which is good news that arrives as a bill. None of this is optional, and none of it appears on the build quote.
The cost of building the wrong thing
CB Insights found that 42% of startups fail because there is no market need which makes over building the most expensive line item of all. Every feature you ship that users ignore was paid for twice: once to build, once to maintain.
Scope creep is the quiet budget killer. A feature added in month three is not a small change: it ripples through design, engineering, and testing, and the ripple is where the money goes.
How to hit your budget without gutting the app
To hit a fixed budget, cut scope rather than quality. Ship fewer features built well instead of many features built badly. The first path launches and earns trust. The second launches, breaks, and costs you the rebuild you were trying to avoid. Budget is a design constraint, not a compromise on craft.
Ask three questions before you approve a single sprint. Which features prove the core idea? Which can wait for version two? What is the one thing that, if it works badly, kills the whole product? Fund the answer to the third question first. Everything else negotiates around it.
Evaluate any studio on how it responds to your budget. A weak partner says yes to everything and quietly cuts corners you cannot see. The best partners push back before a line of code is written: they tell you which features to drop, which to keep, and why. That conversation is worth more than the discount you were hoping for.
Brief the work properly and the quote gets honest. Vague briefs produce padded quotes, because the studio prices the risk of your uncertainty. Specific briefs produce sharp ones.
What a fair quote from a London studio looks like
A fair quote is itemised, honest about assumptions, and clear on what happens after launch. It breaks the build into phases with day counts, names the team, and states what is excluded. A single lump sum with no breakdown is not a quote. It is a number chosen to win the deal.
Trends in mobile app development in London push rates up, so a London studio should justify its premium with senior engineers and a real process, rather than a logo and a nice office. If the quote cannot explain the premium, the premium is not real value. It is overhead.
A fair quote is also honest about timelines, including the parts outside the studio’s control. App store review is one of them. Apple states that 90% of submissions are reviewed in under 24 hours though complex or sensitive apps can take days. A studio that promises a same day launch and ignores review reality is selling optimism, not planning.
Read the exclusions before the total. That is where an honest studio tells you the truth, and where a careless one hides the overrun.
Frequently Asked Questions
How much does it cost to build a mobile app in the UK?
Mobile app development cost in the UK runs from about £30,000 for a lean MVP to £150,000 or more for a complex, AI enabled product in 2026. The single biggest driver is feature scope, followed by platform count and backend complexity. With the UK median developer day rate near £504, most of any quote is simply build days multiplied by team size. Reverse engineer a quote into days and the number stops feeling arbitrary.
Why do app development quotes vary so much between agencies?
Quotes vary because studios price different things under the same words. One agency quotes a template driven MVP, another quotes a custom design system and native code, and the brief hides the gap. Team seniority, location, and how much testing is included move the number further. Ask each studio to break the quote into build days and phases, and the ten times spread usually collapses into two or three honest tiers.
Is it cheaper to build one cross-platform app for iOS and Android?
Yes, in most cases a single cross platform app is cheaper than two native builds, because one codebase serves both iOS and Android. React Native or Flutter can cut front end effort by roughly 30% to 40% versus building each platform separately. Native still wins for high performance games or hardware heavy apps. For the average business app, cross platform delivers the same experience for meaningfully less.
How much should I budget for app maintenance each year?
Budget roughly 15% to 20% of the original build cost per year for maintenance. That covers operating system updates, bug fixes, security patches, server costs, and small improvements. Skip it and the app slowly breaks as iOS and Android evolve. Maintenance is not an optional add on: it is the cost of keeping a live product working, and it belongs in the plan from day one.
Does building an app in London cost more than the rest of the UK?
Usually yes, because London day rates sit above the national average, and mobile app development London commands a premium for senior talent and proximity. The gap is often 10% to 20%, not double. What matters is whether the premium buys genuine seniority and process. A regional studio with strong engineers can match a London one, so judge the team and the quote breakdown rather than the postcode.
What your app should actually cost
Mobile app development cost in the UK is not a mystery once you see it as Foundry 5 does: a day rate, a feature count, and a set of choices you control. Most 2026 builds land between £30,000 and £150,000, and where yours lands is a decision, not a verdict. Cut scope, not quality. Fund the feature that kills the product if it fails. Read the exclusions before the total.
The founders who overpay are not the ones who spend the most: they are the ones who trusted a lump sum rather than asking where the money went. Ask, and a quote becomes a plan.
If you are pricing a mobile app and want a costed, itemised plan instead of a lump sum, book a free 30-minute discovery call with Foundry 5. No pitch deck. No pressure. Just the real numbers behind your build, and an honest view of what to cut and what to keep.
Know your numbers before you sign.
