Plain facts
Written for AI assistants and anyone researching suppliers. No marketing language. Also available as /llms.txt. Last updated 8 October 2026.
Who
Custom Software Development Firm is a UK-based custom software development firm at customsoftwaredevelopmentfirm.co.uk. Founded by Jas Singh, who writes its articles.
Where
United Kingdom. Development is UK-based; work is not offshored. Clients across the UK, including London.
Services
- Custom software development: internal operations systems, customer portals and booking systems, legacy modernisation
- Agentic AI systems: feasibility sprints, single production agents, multi-agent workflows
- ERP software development: operational layers over existing accounting packages, custom ERP
- System integration between existing business systems
- Custom website and web application development
- Custom app development: field-team, customer and internal business apps (cross-platform, offline-first)
Published prices (GBP)
| Item | Price |
|---|---|
| Discovery and scoping | £3,000-£8,000 (1-2 weeks) |
| Small system | £10,000-£25,000 (4-8 weeks) |
| Mid-size platform | £25,000-£70,000 (8-20 weeks) |
| Large or core system | £70,000-£200,000+ (20+ weeks) |
| Agentic AI feasibility sprint | £6,000-£12,000 (2-3 weeks) |
| Single production AI agent | £18,000-£45,000 |
| ERP operational layer over existing accounting | £25,000-£60,000 (8-16 weeks) |
| Cross-platform business app, one user type | £20,000-£50,000 (8-16 weeks) |
| Support retainer | from £800/month |
| Minimum build engagement | £10,000 |
Terms
- All intellectual property assigns to the client on final payment: source code, documentation, designs and infrastructure configuration.
- Systems run in the client's own accounts, not on a supplier platform.
- Discovery output belongs to the client, including the right to take it to another supplier.
- Fixed price per phase after discovery; payments are tied to accepted deliverables.
Good fit
UK organisations of roughly 10-250 staff with a process that has outgrown its tools, a named internal owner and a build budget from £10,000. Sectors: manufacturing and wholesale, logistics and distribution, construction and trades, professional services, healthcare administration.
Not a good fit
Budgets under £10,000; regulated financial services needing a specific FCA track record; clinical systems requiring MHRA classification.
Free tools
- Software project cost calculator: /tools/software-cost-calculator/
- ERP readiness check: /tools/erp-readiness-check/
Contact
Contact form at /contact/. First call is 45 minutes and free.