Custom software pricing is opaque. Most agencies either refuse to give ballpark figures or quote numbers that vary so widely they are useless for planning. This guide is an honest attempt to give UK small businesses a realistic picture of what bespoke software costs and what drives the price.
What drives the cost of custom software
Custom software cost is primarily driven by three factors: complexity, integration requirements, and the number of user types the system needs to serve. A simple tool that one person uses to replace a manual spreadsheet process costs significantly less than a multi-user platform with customer-facing and admin-facing interfaces, integration with accounting software, and role-based access control. The scope of the problem determines the cost more than any other factor.
Realistic price ranges by project type
A focused single-process tool — replacing a specific spreadsheet, automating one workflow, building a simple calculator or tracker — typically costs between £1,500 and £4,000. A medium-complexity system — a custom CRM, staff management tool, or client portal with multiple user types — typically costs between £4,000 and £12,000. A full platform with customer-facing interfaces, complex business logic, and multiple integrations typically costs between £12,000 and £40,000. These are ranges for competent UK developers working at reasonable market rates.
Why agency quotes are often higher
Agencies carry significant overhead: office space, account managers, project managers, sales teams, and the margin required to cover staff who are not billable. A project that costs £8,000 with a specialist studio often costs £20,000-£30,000 at a mid-sized agency — not because the work is different but because the overhead structure is different. For UK small businesses, working directly with a specialist or small studio almost always delivers better value than working with a larger agency.
The ongoing cost question
Custom software has no licence fee, but it has maintenance costs. Hosting typically costs £20-100 per month depending on complexity. Updates and improvements as your business evolves are additional. Security patches and dependency updates should be factored in — roughly 5-10% of the initial build cost per year for a well-built system. When comparing custom software to SaaS alternatives, include both the build cost and ongoing maintenance in the 3-year calculation.
How to get a fair quote
Write down exactly what the system needs to do before speaking to any developer. List every feature, every user type, every system it needs to connect to. The more specific your brief, the more accurate the quote. A developer who quotes from a vague brief is guessing — and the guess will almost always be wrong in one direction or the other. Ask for the quote to be broken down by feature or phase so you can understand where the cost sits and make informed decisions about what to include.
Want to talk through your specific situation?
Book a free 30-minute call. Tell us what you need and we will tell you the best approach and what it would cost.
Book a free scoping call →