"How much does custom software cost?" might be the most frustrating question in business technology. Most companies answer with "it depends" or "contact us for a quote"—leaving you with no way to budget or evaluate options.
Here's the transparency that question deserves: realistic UK pricing for custom business software in 2025, based on actual project experience.
What Drives Software Costs
Before the numbers, understand what you're paying for:
Complexity determines cost. A simple data capture form is not the same as a full enterprise resource planning system. More features, more integrations, more user types, more complexity—more cost.
Quality has a price. Software can be built quickly and cheaply, or properly and reliably. Cheap usually means cutting corners on testing, security, documentation, and architecture. Those shortcuts create costs later.
Ongoing support matters. Building software is one cost. Maintaining it, hosting it, updating it, and supporting users are recurring costs that last the lifetime of the application.
UK rates are UK rates. Good UK developers charge £60-£120/hour. A web development agency or software development consultancy in London typically bills £80-£150/hour. Offshore options exist but create coordination challenges that often consume the savings.
Now, the numbers.
Simple Internal Tools: £5,000-£20,000
What you get:
- Single-purpose applications (data entry, simple workflows, basic dashboards)
- Limited user roles (typically admin and standard user)
- Integration with one or two existing systems
- Basic mobile responsiveness
- Standard security appropriate for internal use
Examples:
- Equipment booking system
- Simple approval workflow
- Internal knowledge base
- Basic inventory tracker
- Meeting room scheduler
Timeline: 4-8 weeks
Why this range: Complexity varies even within "simple." A booking system with availability logic costs more than a static form. Integration with a well-documented API costs less than integration with legacy systems.
Mid-Level Business Applications: £20,000-£75,000
What you get:
- Multi-purpose applications with several modules
- Multiple user roles with different permissions
- Integration with key business systems (accounting, CRM, etc.)
- Reporting and dashboard capabilities
- Mobile apps or responsive design
- Robust security and audit logging
- User documentation and training materials
Examples:
- Client portal with document management
- Custom CRM tailored to your sales process
- Operations management platform
- Staff scheduling and resource allocation
- Customer self-service application
Timeline: 10-20 weeks
Why this range: This tier covers most SME custom software needs. A client portal with basic document sharing sits at the low end. A portal with e-signatures, payment integration, custom workflows, and detailed reporting sits at the high end.
Full Business Applications: £75,000-£200,000+
What you get:
- Comprehensive platforms replacing or supplementing core business systems
- Complex business logic and workflows
- Extensive integration with multiple systems
- Advanced analytics and business intelligence
- Native mobile applications (iOS and Android)
- Enterprise-grade security and compliance
- Full documentation, training, and support setup
Examples:
- Industry-specific ERP system
- Multi-sided marketplace platform
- Complex booking and fulfilment system
- Financial services application with regulatory compliance
- Field service management with mobile workforce apps
Timeline: 20-40+ weeks
Why this range: At this level, you're building significant business infrastructure. Projects exceed £200,000 when they involve multiple integrated modules, complex compliance requirements, or enterprise-scale architecture.
What's Included (and What's Not)
These prices typically include:
- Requirements gathering and specification
- UX/UI design
- Development and testing
- Deployment and go-live support
- Basic documentation
- Short warranty period for bug fixes (usually 30-90 days)
These prices typically don't include:
- Ongoing hosting (usually £50-£300/month depending on scale)
- Ongoing maintenance and support (usually 10-15% of development cost annually)
- Major feature additions after launch
- Third-party service costs (payment gateways, SMS, email services)
Price vs Quality
You can find developers who quote significantly lower than these ranges. Understand what you're accepting:
Very cheap development typically means:
- Offshore teams with communication challenges
- Junior developers learning on your project
- Minimal testing and quality assurance
- No documentation
- Abandoned support after launch
- Technical debt that creates problems later
We've rebuilt multiple systems that were "done cheap" the first time. The total cost always exceeds doing it properly initially.
How to Budget
When planning a custom software project:
Get clear on requirements first. Vague requirements lead to vague quotes. Document what you need before approaching a bespoke software development agency or web app development consultancy.
Expect 20-30% contingency. Requirements evolve, unexpected complexity surfaces, priorities shift. Budget for reality, not best case.
Include ongoing costs. Development is typically 60-70% of first-year cost. Don't forget hosting, support, and inevitable enhancements.
Compare like with like. Different proposals may include or exclude different elements. Standardise before comparing prices.
The Bottom Line
Custom software is a significant investment—but so is working around inadequate tools for years. A £30,000 application that eliminates £50,000 in annual workarounds pays for itself in under a year.
These prices reflect UK market reality in 2025. Use them to budget realistically, evaluate proposals sensibly, and make informed decisions about whether working with a custom software development agency in London or elsewhere makes sense for your business.