“How much does it cost to build an app?” is one of the most persistently searched questions in the UK software market. In 2026, with AI app builders promising to cut costs to near-zero, the question has a more complicated answer than it did two years ago. Here’s what the data actually shows.
The headline numbers
According to current UK market data, the average app project budget sits around £90,780. The range breaks down roughly as:
- Basic startup apps (simple functionality, limited integrations): £15,000 – £40,000
- SME apps (custom dashboards, third-party integrations, CMS): £40,000 – £100,000
- Enterprise apps (complex workflows, compliance, scale): £100,000 – £500,000+
Adding one or two genuine AI features — not just calling a chatbot API, but real AI-driven functionality — typically adds £15,000–£45,000 on top of those figures, plus ongoing infrastructure costs of £500–£2,500/month. For products where AI reasoning is the core product, expect build costs of £80,000–£350,000+.
UK developer day rates in 2026: junior £300–£450/day, mid-level £450–£600/day, senior £500–£700/day, AI or architecture specialist £700–£1,000/day.
What AI tools have actually changed
AI development tools are compressing timelines meaningfully. Discovery and prototyping phases that used to take 6–8 weeks can now run in 2–3. Boilerplate code generation is faster. For simple consumer apps with limited custom logic, AI-assisted builds are genuinely cheaper than they were in 2023.
What hasn’t changed: compliance requirements, integration complexity, security architecture, QA, and the cost of maintaining software after launch. These are typically 40–60% of total project cost and aren’t significantly affected by AI tooling.
Where the floor actually is
AI app builders can produce a working prototype for close to zero. A production-ready, integrated, secure application is a different category. The question isn’t whether AI can build an app — it can sketch one. The question is whether the output will work reliably in the real world over a multi-year lifecycle.
For founders researching costs, the most useful question to ask any agency or developer isn’t “can you build it cheaper with AI?” but “what’s included in the price and who’s responsible if it breaks?”
If you’re scoping a project, the custom software development page covers how we approach budgeting and scoping for UK clients. Or start a conversation.