Quotes for the same piece of bespoke (custom) software can differ several times over. On the projects we have measured, typical UK agency quotes ranged from £4,000 for a marketing website with an enquiry system to £35,000 for a connected mobile and web platform. The price is driven by scope, the systems the software has to connect to, how sensitive the data is, and how the team works, which now includes how well it uses AI.
Real projects: the typical quote and what it cost
Every engagement we complete is benchmarked against the typical agency quote for the same scope. These are the measured projects so far, with links to the full case studies.
| Project | Typical agency quote | LiteByte delivered |
|---|---|---|
| Chameleon AccessConnected Mobile & Web Platform Engineering | £35,000 · 6 months | £5,000 · 5 weeks |
| GET IN!Online Assessment & Interview Training Platform | £25,000 · 4 months | £3,000 · 3 weeks |
| Danzee CollectionProperty Marketing & Enquiry Website | £4,000 · 1 month | £500 · 10 days |
| Locked InFull-Stack Mobile Product Engineering | £18,000 · 8 months | £6,000 · 6 weeks |
| Bantham RadarRegulated Clinical Platform Engineering | £34,000 · 6 weeks | £4,000 · 2 weeks |
| London ShoeshineWebsite, Commerce & Operations CRM | 3 monthsCost not published | 5 daysCost not published |
Two things stand out. First, the typical quotes vary by almost nine times across these projects, because the scopes are very different. Second, the gap between a traditional quote and an AI-assisted build is large, but it depends on the work being specified and reviewed by experienced engineers. Speed without that review is where AI-built software goes wrong.
What does each type of project cost?
Grouped by type of project, the same figures give a rough guide. Every range comes from a project we have delivered and measured. Where we haven't measured a type of project yet, the table says so rather than guess.
| Type of project | Typical agency quote | LiteByte delivered |
|---|---|---|
| Marketing website with an enquiry systemFrom: Danzee Collection | £4,000 | £500 |
| Website with bookings, memberships and an operations CRMFrom: London Shoeshine | Not published | Not published |
| Web platform with sign-in, payments and AI featuresFrom: GET IN! | £25,000 | £3,000 |
| Mobile app with its backendFrom: Locked In | £18,000 | £6,000 |
| Business system: connected platforms, CRM or regulated workflowsFrom: Chameleon Access, Bantham Radar | £34,000–£35,000 | £4,000–£5,000 |
| Legacy system rebuildNo measured rebuild published yet. Every rebuild starts with a free system audit and a written proposal. | Not published | Not published |
Why do quotes for the same software vary so much?
Most of the variation comes from what each team assumes the brief means. A vague brief gets priced for risk: the team adds time for the parts it can't see yet. A clear brief gets priced for the work.
- Scope: how many types of user, how many screens and workflows, and what happens at the edges (refunds, cancellations, permissions).
- Integrations: connecting to your existing systems (accounting, CRM, Microsoft 365, payment providers, or specialist systems such as clinical records) is often the largest single cost.
- Data: migrating data from an old system, and keeping it accurate while both systems run, takes careful work.
- Compliance and security: software that handles personal or special category data needs access control, audit trails and testing built in from the start.
- Platforms: a website, a web application and a mobile app each carry different costs; doing all three on one shared data model is cheaper than building them separately.
- The team's process: how much is senior time, how much is junior time, and how much of the routine work is done with AI under review.
What costs do people forget?
The build is only part of the cost of owning software. Before you compare quotes, check that each one covers:
- Hosting and infrastructure, which grow with your usage.
- Monitoring, maintenance, security updates and bug fixes after launch.
- Changes you will want once real users arrive: there are always some.
- Third-party services the software relies on, such as payments, email, maps or AI models, which usually bill you directly.
- Who owns the code and the intellectual property when the project ends.
Fixed price, day rate or monthly rate: which is better?
- Fixed price: one figure for a defined scope. Predictable, but any change becomes a variation, and the price includes a buffer for the risk the agency is taking.
- Day rate (time and materials): you pay for time spent. Flexible, but the total is hard to predict and you carry the risk of overruns.
- Flat monthly rate: the model we use. A written proposal sets the scope and timeline first; development then runs at a fixed monthly rate, and maintenance after launch moves to a lower monthly rate. The cost is predictable month to month and changes can be absorbed as the work evolves.
Whichever model you choose, insist on a written proposal that states what will be built, when it lands and what it costs to run afterwards.
How do you get an accurate quote?
- Describe the problem and the people who will use the software, not just a list of features.
- List the systems it must connect to, and where your data lives today.
- Say what's fixed (a deadline, a budget, a regulation) and what's flexible.
- Ask every team how they handle changes, testing, security and support after launch.
- Ask to see work of similar scope, with what it cost and how long it took.
When is custom software not the right answer?
If your processes are standard and an off-the-shelf product fits them, a subscription is usually cheaper than building. Custom software earns its cost when the off-the-shelf tools force your team to work around them, when you are paying for several tools to do one job, or when the way you work is part of what makes your business different.
Common questions
How much does a simple business website cost?
For a marketing website with an enquiry system, the typical agency quote in our measured projects was £4,000. Costs rise with bookings, payments, accounts and integrations.
How much does a mobile app cost in the UK?
In our measured mobile projects, typical agency quotes were £18,000 and £35,000 (the second included two web platforms and a shared backend). Your quote depends on the platforms, features and backend the app needs.
How much does a bespoke business system or CRM cost?
On the business systems we have measured (connected operations platforms with a CRM, and a regulated clinical platform), typical agency quotes were £34,000 and £35,000. We delivered them for £4,000 and £5,000. The cost depends mostly on the workflows, the integrations and how sensitive the data is.
How much does it cost to modernise a legacy system?
We haven't published a measured legacy rebuild yet, so we won't quote a typical figure. The price depends on how much of the old system is kept, how much data moves and what it connects to. We start with a free system audit and a written proposal.
Is AI-built software cheaper?
It can be much faster and cheaper to build, but only if experienced engineers specify the work and review every line. Unreviewed AI output creates new routes for defects and security issues to reach production.