Top 10 IT Companies in the UK 2026

A lot of things in the UK run on software: payroll, medical records, railways, banking, even council tax. Thousands of IT companies keep all of it running, and most people never think about them.

The scale is bigger than you might think. Computacenter alone reported revenue of £9.2 billion in 2025, an increase of 32% on the previous year. Sage, Softcat and Kainos all posted double-digit growth in their latest results, and AI work is now showing up as a real line in their numbers.

The market isn’t one thing, though. Some of these companies sell hardware and cloud services in large quantities. Others create the software used by small and mid-sized businesses, and some help defend organizations from cyberattacks.

That’s why, when we put this list together, we looked at what each company does and what it excels at. Below you’ll find each company’s current revenue, UK headcount and headquarters, along with its 2026 news. This guide looks at the top 10 IT companies in the UK for 2026, from FTSE 100 giants to specialists that punch above their size.

Why Businesses Work With the Top IT Companies in the UK

Scale and Buying Power

The largest resellers, such as Computacenter, Softcat and Bytes, buy from Microsoft and other major vendors in huge volumes. That lets them offer better pricing and stock availability, and they have specialist staff who understand licensing.

Security That Keeps Pace

Cyberattacks on UK organizations have made security a board-level issue. Companies such as Darktrace and NCC Group specialize in keeping organizations protected with tools and testing skills most in-house teams can’t build alone.

Delivery Capacity on Demand

Companies like TCS, Capita, Endava and Kainos can supply engineers in large numbers to meet a client’s needs, whether that means migrating a platform or creating a new digital service on a fixed deadline.

Practical AI Adoption

Many businesses want to bring AI into their day-to-day work without starting over. The top 10 IT companies in the UK are now building AI into accounting software, security platforms and managed services to make that possible.

Top 10 IT Companies in the UK at a Glance

Top 10 IT Companies in the UK (2026)

Here is how the top 10 IT companies in the UK compare, with the facts that matter for buyers.

1. Computacenter

Computacenter was established in 1981 by Philip Hulme and Peter Ogden. Headquartered in Hatfield, Hertfordshire, it has around 20,000 employees and is a FTSE 100 company. It supplies large business and government clients with technology, services and support across the UK, Germany, France and North America.

In 2025 the company posted a big jump in revenue, up 32% to £9.2 billion, while group invoiced income reached £13 billion. Technology sourcing grew 40.9% to £7.5 billion and services grew to £1.7 billion. The UK business returned to growth after a weak 2024. In January 2026 Computacenter completed its $120 million acquisition of AgreeYa to grow its professional services offering, and it entered 2026 with a record committed order pipeline of £7.1 billion.

Key IT Solutions
✔ Technology sourcing and supply chain
✔ Managed services and service desk
✔ Professional services and data center projects
✔ Workplace and device lifecycle management

Best for: Large enterprises and public bodies that need one partner for buying, deploying and running IT at scale.

2. Sage Group

Sage was established in Newcastle upon Tyne in 1981 and has kept its headquarters there. Known for its accounting software, it is one of the biggest software companies in the UK, a FTSE 100 member that employs more than 11,000 people. Sage provides accounting, payroll, HR and financial management software to small and mid-sized businesses around the world.

For the year ended September 30, 2025, Sage grew revenue 8% to £2.513 billion, and statutory operating profit rose 17% to £530 million. Growth then picked up. In the nine months to June 2026, revenue rose 11% to £2.06 billion, cloud native revenue increased 25% to £794 million, and revenue in the UK, Ireland and Africa region grew 10% to £602 million. Sage Copilot and new AI agents now help customers with everyday finance tasks, under long-serving CEO Steve Hare.

Key Software Solutions
✔ Sage Accounting for small businesses
✔ Sage Intacct for mid-sized firms
✔ Payroll and HR software
✔ Sage Copilot AI assistant

Best for: Small and mid-sized businesses that want proven cloud accounting and payroll software.

3. Tata Consultancy Services (UK)

Tata Consultancy Services is headquartered in Mumbai, but its UK operation is one of the largest IT employers in the country. TCS has worked with UK enterprises for more than five decades. It employs about 15,300 people in technology roles across 19 UK sites, and its activity supports roughly 42,700 jobs directly and indirectly.

The UK accounted for 18% of TCS revenue in the quarter ending June 2025. TCS says it added £3.3 billion to the UK economy in FY2024 and paid more than £780 million in UK taxes. In October 2025 it announced 5,000 new UK jobs over the next three years and opened its AI Experience Zone and Design Studio in London. Clients include Virgin Atlantic, which has worked with TCS for more than 20 years.

Key IT Solutions
✔ Application development and management
✔ Cloud and infrastructure services
✔ AI and data consulting
✔ Business process services

Best for: Large enterprises running multi-year transformation programs that need global delivery scale.

4. Softcat

Softcat was founded by Peter Kelly in 1993 as Software Catalogue in High Wycombe and is now headquartered in Marlow, Buckinghamshire. It is a FTSE 250 company with more than 2,600 employees, supplying software, hardware, cloud and security products to businesses and public sector bodies.

Softcat had another strong year to July 31, 2026. Revenue increased 35.4% to £1.98 billion, gross invoiced income rose 30.5% to £4.72 billion and underlying operating profit grew 19.4% to £215.1 million. It ended the year with £199.9 million in net cash and raised its full-year dividend by 7.5%. After the year end, Softcat announced the acquisition of GDT, a US multi-vendor IT solutions provider, to expand into the United States. CEO Graham Charlton leads the business.

Key IT Solutions
✔ Software licensing and cloud
✔ Networking and data center infrastructure
✔ Cybersecurity products and services
✔ Managed and professional services

Best for: Mid-market and public sector organizations that want a responsive, single reseller for most of their tech stack.

5. Capita

Capita was founded in 1984 and is headquartered in London. It is one of the UK’s leading technology-led outsourcing groups, providing digital services, contact centers and back-office operations to government, local authorities and businesses. It is led by CEO Adolfo Hernandez.

Capita’s adjusted revenue rose 1.6% to £906.4 million in the six months to June 30, 2026. It won new contracts worth £998 million, up 15% on the prior year, including a £425 million renewal with Transport for London. It also won work with Kent County Council, Staffordshire County Council and the Army Collective Training Service. Capita plans to roll out more AI and “agentification” across client and internal operations in the second half of 2026.

Key IT Solutions
✔ Public service delivery platforms
✔ Customer experience and contact centers
✔ AI-driven process automation
✔ Back-office administration services

Best for: Public bodies and large firms outsourcing complex, high-volume services.

6. Endava

Endava was founded in 2000 and has its headquarters in London. It has been listed on the New York Stock Exchange since 2018 and had 11,225 employees at the end of March 2026. Endava provides custom software development and platform modernization for clients in payments, banking and other industries.

The numbers have been weak in 2026. Revenue fell 8.4% to £178.5 million in the three months to March 31, 2026, and the company booked a large non-cash goodwill impairment. It expects full-year revenue of £721.8 million to £725.8 million. One bright spot is AI: AI-driven work now makes up 15% of revenue, up from 5% a year earlier. Endava recently began a collaboration with Mastercard and was selected by Tyl by NatWest to modernize its payments platform. John Cotterell leads the company as CEO.

Key IT Solutions
✔ Custom software engineering
✔ Payments and banking platforms
✔ Cloud and data modernization
✔ AI-enabled development

Best for: Financial services and payments firms that need deep engineering talent.

7. Kainos

Kainos was established in Belfast in 1986 as a joint venture between Fujitsu and QUBIS, the business incubation unit of Queen’s University Belfast. The company is still based in Belfast, is a FTSE 250 member and has 3,216 staff. It is best known for building digital public services and for its large Workday practice.

For the year ended March 31, 2026, revenue increased 17% to £431.1 million and adjusted profit before tax reached £67.1 million. Kainos grew its workforce by 420, including 120 staff from Davis Pier in Canada. Workday Products annual recurring revenue rose 23% to £89 million, and the company expects it to reach £100 million by the end of 2026. Revenue from AI and data work increased 11% to £45.8 million. CEO Brendan Mooney called it “a positive year for Kainos.”

Key IT Solutions
✔ Digital service design and delivery
✔ Workday deployment and testing products
✔ AI and data engineering
✔ Cloud migration

Best for: Government departments and Workday customers that want a proven UK delivery partner.

8. Darktrace

Darktrace was established in Cambridge in 2013 and is still based there. It is known for self-learning AI that detects unusual activity across networks, email, cloud and industrial systems. US private equity group Thoma Bravo bought the company for $5.3 billion in a deal completed in October 2024.

Darktrace now has nearly 10,000 customers and employs more than 2,300 people. It bought Cado Security in 2025 to strengthen cloud forensics and response. In March 2026 it named Ed Jennings as president and CEO; he previously served as CEO of Quickbase and COO of Mimecast. Darktrace has filed more than 200 patent applications, and its Darktrace / EMAIL product has gained almost 5,000 customers since 2019.

Key Security Solutions
✔ ActiveAI Security Platform
✔ Darktrace / EMAIL
✔ Darktrace / NETWORK and / OT
✔ Cyber AI Analyst

Best for: Organizations that want AI-led threat detection across email, network and operational technology.

9. Bytes Technology Group

Bytes Technology Group was founded in 1982 out of a small shop in Epsom and is now headquartered in Leatherhead, Surrey. It became a listed company in December 2020 when it demerged from Altron. Bytes operates through two businesses: Bytes Software Services and Phoenix Software, which focuses on the UK public sector.

In the year ended February 28, 2026, gross invoiced income increased 11.5% to £2.34 billion. Operating profit fell 5.6% to £62.7 million, reflecting changes to Microsoft’s partner incentives and Bytes’ investment in its people. Headcount grew 6.9% to 1,331. Bytes is now a Microsoft Frontier Partner and came 14th in the FT’s UK Best Employers list, the highest position of any reseller. From FY2027, Bytes will focus on the private sector and Phoenix on the public sector.

Key IT Solutions
✔ Microsoft licensing and advisory
✔ Cloud and AI services
✔ Security solutions
✔ Software asset management

Best for: Organizations with heavy Microsoft estates that want to control licensing costs.

10. NCC Group

NCC Group was formed in 1999, when the National Computing Centre sold its commercial divisions to management. NCC is headquartered in Manchester, listed in the FTSE 250 and has more than 2,000 employees. It has built its name in penetration testing, security consulting and managed detection.

For the half year ended March 31, 2026, group revenue was up 5% at £151.3 million and cybersecurity revenue reached £118.4 million. The UK and APAC cyber business grew 12.5% to £73.9 million. In May 2026, NCC completed the sale of its Escode software escrow business to TDR Capital for net cash proceeds of £262.8 million, leaving it focused purely on cybersecurity. CEO Mike Maddison described the period as “a solid first half.”

Key Security Solutions
✔ Penetration testing and technical assurance
✔ Managed detection and response
✔ Incident response
✔ Security consulting and integration

Best for: Firms that need independent security testing and expert incident response.

Also read: Top 10 IT Companies in India

How to Choose the Right IT Partner in the UK

Start With the Problem

Decide whether you need a product, people or an outcome. If you need licenses and equipment, look at resellers like Softcat or Bytes. If you’re building something new, a delivery partner such as Kainos or Endava may suit you better.

Check Sector Experience

Ask for references within your industry. Public sector work, payments and healthcare all come with regulations that a generalist may learn slowly and at your expense.

Look at Financial Strength

Look at the provider’s latest results before you sign a long contract. Companies with growing revenue, healthy cash and stable leadership are more likely to be around to support you in the future.

Test Security Credentials

Ask which security accreditations the provider holds and whether it has suffered any incidents. Any partner with access to your systems becomes part of your attack surface, so make sure it can look after your data.

Agree Clear Terms

Put service levels, exit terms and pricing in writing. The best IT companies in the UK will want clear contracts too, because they protect both sides.

Frequently Asked Questions About IT Companies in the UK

Which is the largest IT company in the UK?

Computacenter is one of the largest UK-headquartered IT companies by revenue, with £9.2 billion in 2025. Sage is one of the biggest software companies listed in the UK. TCS is one of the largest IT employers in the country, though it is headquartered in India.

Which UK IT company is best for small businesses?

There is no single best for everyone; it depends on your requirements. Sage is a go-to choice for accounting and payroll software, while resellers such as Softcat serve businesses of many sizes. Smaller firms should make sure they get the level of support they need and compare pricing before signing.

Which UK IT companies specialize in cybersecurity?

Darktrace and NCC Group are the leading security specialists among the top 10 IT companies in the UK. Darktrace focuses on AI-led detection, while NCC is known for testing, consulting and incident response. Many of the larger firms also offer security as part of their services.

How are UK IT companies using AI in 2026?

Most of the top 10 IT companies in the UK are building AI into their current offerings. Sage has launched Copilot and AI agents, Kainos and Endava are reporting growing AI revenue, and Capita plans to expand AI automation. For buyers, it comes down to how AI can cut cost or risk in their own organization.

Conclusion

From supplying products to running the books, the top 10 IT companies in the UK cover very different ground. Computacenter, Softcat and Bytes keep organizations supplied, Sage serves millions of customers, and TCS, Capita, Endava and Kainos deliver large programs. Darktrace and NCC Group help keep it all secure.

The right choice depends on what you need, how fast you need it and how much risk you can carry. Use this list of the top 10 IT companies in the UK as a starting point, then check each shortlisted name against your own requirements.