Product discovery
We start by mapping how your business actually runs today. People, processes and pain points come first, before a single screen is designed or a line of code is written.
[ CUSTOM SOFTWARE ]123DIGI · Service
Custom Software Development
123Digi is a UK custom software development company. We design and build bespoke software around your business processes, your team and your growth goals, so the technology fits the business instead of the other way round.
- Studio
- 123DIGI
- Based
- Colchester, UK
- Coverage
- UK-wide
- Engagement
- Sprint or retainer
[ THE PROBLEM ]
What we usually see when clients reach out.
Off-the-shelf tools only solve half the problem. You end up gluing spreadsheets to SaaS, duplicating data across inboxes, and paying skilled people to push information between systems. The software starts to shape how the business runs, rather than supporting how it should run.
[ HOW WE FIX IT ]
A measured, senior-led approach.
We start with a short discovery, map your real workflows, and then design and build custom software that genuinely fits. We use a typed, modern stack with clean architecture and proper documentation, so the system is fast today, easy for a future developer to maintain, and ready to scale with the business for years.
Specific, repeatable work, not vague promises.
System architecture
Clean, typed architecture that is secure by default, fast under real load and ready to scale as your customer base and team grows.
Design and engineering
Senior UK product designers and engineers work together and ship in small, reviewable releases, so you see progress every couple of weeks.
Launch and support
We do not disappear after launch. We monitor, support and evolve the software as your business changes, with clear SLAs and a single senior point of contact.
[ WHO WE WORK WITH ]
Built around the people who actually buy this work.
- Founders and CEOs
- Managing directors
- Operations leaders
- Heads of IT
[ INDUSTRIES ]
Where we have the deepest pattern recognition.
- Automotive and service
- Wholesale and trade
- Professional services
- Field operations
- Healthcare and clinics
[ PROCESS ]How we work
From idea to live software in five honest steps.
Discover, design, develop, launch and grow. A simple process that takes your idea, turns it into real software your team uses every day, and keeps improving the system after it goes live.
01Act 1
Discover
We sit down with you, map how your business runs today and agree exactly what the software needs to do for your team and your customers.
01 / 05
02Act 2
Design
We plan the user experience, design the screens and agree the system architecture before a single line of production code is written.
02 / 05
03Act 3
Develop
We build the software, web app, mobile app or integration on modern, typed technology, shipping in small releases you can review and test.
03 / 05
04Act 4
Launch
We test, deploy and support the new system so it works the day it goes live and keeps working under real-world use.
04 / 05
05Act 5
Grow
We help you grow the system after launch with SEO, performance improvements, new features and ongoing automation.
05 / 05
The questions buyers ask us most often about custom software.
How much does custom software development cost in the UK?
Most UK custom software projects with 123Digi start around £18,000 for a focused MVP and typically sit between £35,000 and £120,000 for a full production system. We always agree a fixed scope and a transparent price before engineering starts.
How long does a custom software project take?
Most projects go from discovery to the first usable release within 6 to 12 weeks. We ship in small, reviewable releases so you can see and test progress well before the full build is complete.
Do you work alongside our internal IT or developers?
Yes. We regularly work with in-house IT, product and operations teams. We hand over clean Git repositories, document our architecture decisions and provide training so your team can own the system if you ever need to.
What technology do you build on?
We build on modern, typed stacks including Next.js, TypeScript, Node, Postgres and Prisma, hosted on Vercel or AWS. Everything is secure by default and easy for another senior engineer to pick up.
Will we own the code and the data?
Yes. You own the source code, the infrastructure and the data. We support and maintain it for as long as you want us to, and you are never locked in.
Custom Software in the wild. Selected case studies.
Brand · Website · Web App · SEOWebsite · Local SEO · UXWebsite · Booking · UX
Keystone Tyre
A wholesale tyre brand and trade platform serving customers across the United Kingdom.
Mobile Tyre Pro
Mobile tyre fitting across Essex with a website built for local search and quick bookings.
Tyres24
A 24/7 mobile tyre fitting website for cars, vans, trucks and heavy vehicles.
Pair this with another service for compounding results.
ServiceServiceService
Web Application Development
123Digi builds secure, scalable web applications for UK businesses. Dashboards, customer portals, booking systems and internal tools, designed around how your team actually works and engineered to run at real production scale.
AI Integration
123Digi is a UK AI integration company. We design practical AI chatbots, smart tools and workflow automations and wire them directly into your websites, apps and business systems, so AI earns its keep instead of sitting on a demo slide.
Business Automation
123Digi automates UK businesses. We map the busywork, connect your tools and build the workflows, so your team stops moving data between systems and starts focusing on customers and growth.
Ready to scope a custom software engagement? Send a short brief and we will reply within one business day.
[ NOW BOOKING 2026 · UK-WIDE ]
Readytobuildsmarterdigitalsystemsforyourbusiness?
Whether it is a custom web app, a new mobile app, an AI integration or a full digital overhaul, tell us what you want to build. We reply within one working day with a clear next step and a ballpark timeline.
Free consultation call
Transparent quote & timeline
UK-based senior team