A web application is software people use in a browser — a customer portal, a booking system, an internal tool that replaces a spreadsheet. Unlike a website, it has accounts, data and rules, and that is what you are paying for.
What UK web applications cost in 2026
Softomate's guide (updated October 2026) breaks it down by type. Their figures, not ours:
| Type | Typical cost | Typical time |
|---|---|---|
| MVP or proof of concept | £15,000–£35,000 | 6–12 weeks |
| Internal tool or workflow app | £15,000–£30,000 | 6–10 weeks |
| Customer portal | £30,000–£80,000 | 3–6 months |
| Bespoke CRM | £35,000–£100,000 | 4–7 months |
| Custom e-commerce | £50,000–£150,000 | 4–8 months |
| SaaS or enterprise platform | £100,000–£500,000+ | 9–18 months |
Peachr lands in the same place for first versions: £10,000–£25,000 for a simple web app and £25,000–£60,000 for a web-based SaaS MVP.
Day rates
Most quotes are days multiplied by a rate. Softomate's 2026 UK figures:
- Junior developer: £250–£350 a day
- Mid-level: £400–£550
- Senior: £550–£750
- Lead architect: £600–£900
What moves the price
- Roles and permissions. One kind of user is simple. Customers, staff, managers and admins who each see different data multiply the screens and the testing.
- Integrations. Connecting to Xero, HubSpot, Stripe or Microsoft 365 is routine; connecting to an old in-house system with no documentation is not.
- Data migration. Moving years of records out of spreadsheets or an old system, and cleaning them on the way, is often underestimated.
- Reporting. Dashboards and exports are frequently the feature people care about most, and the one added last.
- Compliance. Personal data, payments and health data each add design and documentation work.
The cost nobody quotes: running it
Softomate puts maintenance at 15–25% of the build cost every year, hosting at £50–£500 a month, and argues that post-launch costs make up 60–70% of what an application costs over its life. Their worked example: a £50,000 build that costs £131,600 over five years.
That is not a reason to avoid building. It is a reason to compare a quote against the off-the-shelf subscription it would replace over the same five years — we walk through that in bespoke vs off-the-shelf software.
How to keep the cost down
- Launch the smallest useful version. Replace the one spreadsheet that hurts most, not the whole operation at once.
- Prototype first. A clickable prototype finds the misunderstandings while they are cheap to fix.
- Own the code and the accounts. It keeps the next supplier — or your first in-house developer — from having to start again.
Sources
- The True Cost of a Custom Web Application for UK Businesses — Softomate Solutions, 7 June 2026, updated 1 October 2026
- How Much Does It Cost to Build an MVP in the UK? (2026 Guide) — Peachr, 2 June 2026