Company lists · Data refreshed September 2026
Top 25 IT services firms based in London, United Kingdom
RevenueBase identified 1,441 IT services firms headquartered in London, United Kingdom as of September 2026 and tracks 17,318 professional contacts across them, including 4,037 with verified work emails. London is the largest hub.
This list covers IT services firms headquartered in London, United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 27, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest IT services firms based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,039 contacts → | ||||
Indirect evidence “Global business doesn’t have to be complicated.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 616 contacts → | ||||
Strong evidence “Excis is a trusted global IT services company, delivering agile, multilingual support across 150+ countries.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 377 contacts → | ||||
Indirect evidence “Hirexa Solutions is a leading group of companies committed to delivering exceptional services to Fortune 500 clients worldwide.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 333 contacts → | ||||
Indirect evidence “Ubique Systems is a fast growing multifaceted organization which offers a comprehensive array of outsourcing and consulting services for its customers, including recruitment…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 302 contacts → | ||||
Indirect evidence “Cartesian is a specialist consulting firm focused on the global telecommunications, media, and technology industries and is now part of Bounteous, an AI services firm helping…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 286 contacts → | ||||
Strong evidence “At Total IT Global, we elevate your digital journey with cutting-edge innovation, to achieve your vision of ‘the enterprise of the future’.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 279 contacts → | ||||
Indirect evidence “At Six Degrees we’re all about enabling our clients’ success through technology.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 231 contacts → | ||||
Indirect evidence “Since 2008, Flat Rock Technology, a software engineering, SI, Cloud DevOps, Cyber Security, and Customer Experience (CX) company, has been at the forefront of providing innovative…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 194 contacts → | ||||
Indirect evidence “Linnk Group provides staffing, outsourcing and professional services to our clients.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 141 contacts → | ||||
Strong evidence “Deepscale Technologies provide data center, enterprise & managed IT solutions across the globe that enhance how businesses operate.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 139 contacts → | ||||
Indirect evidence “We are the most trusted consulting & Information Technology service partner, who has been thriving hard to deliver customer-centric and proven global competence to our clients all…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 120 contacts → | ||||
Strong evidence “OpticoreIT is an IT Consultancy founded in 2013 to bridge a gap in the market between the major IT services providers and the consultancy market.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 114 contacts → | ||||
Indirect evidence “Axiom is a global information technology, consulting and outsourcing company and services provider.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 107 contacts → | ||||
Indirect evidence “NETbuilder is a leading provider of specialist software, consulting, and fully managed services to Government, Finance, Healthcare, Education, and Commercial markets.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 102 contacts → | ||||
Indirect evidence “At Techary, we believe technology should move as fast as your business.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 96 contacts → | ||||
Strong evidence “Matsco Solutions is a global managed IT service provider built exclusively for the financial services industry.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 96 contacts → | ||||
Indirect evidence “Promise to deliver Servicing Certainty worldwide.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 92 contacts → | ||||
Strong evidence “Headquartered in London, United Kingdom, Geecon combines a passion for Client Satisfaction, Technology Innovation, Business and Management Consultancy, Software Solution and IT…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 91 contacts → | ||||
Indirect evidence “Ovyo provides rapid access to specialist people and teams in software engineering, operations & delivery throughout the streaming/OTT/media, satellite/space and comms industries.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 89 contacts → | ||||
Strong evidence “SysGroup is the services leader for realising AI transformation, as an award-winning managed IT services, cloud hosting, and IT consultancy provider.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 89 contacts → | ||||
Strong evidence “Ultimate IT solutions.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 86 contacts → | ||||
Strong evidence “OneAPPS Consulting is a global services partner providing IT solutions and building high-performance teams for our clients in the BFSI, Communications, Government and Technology…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 84 contacts → | ||||
Strong evidence “IT'S NOT RECRUITMENT.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 84 contacts → | ||||
Strong evidence “SAT Microsystems is a proven IT Service Provider leader in developing innovative solutions that reduce business costs and complexity in Saudi Arabia, UAE, and 8 other countries.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 82 contacts → | ||||
Strong evidence “Welcome to 9NEXUS- Your Trusted Partner for IT Staff Augmentation & Offshore Solutions.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: IT services firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names IT services firms.
- Partial evidence
- Its own public description names part of IT services firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name IT services firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 1,441 IT services firms based in London, United Kingdom
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IT services firms based in London, United Kingdom at a glance
As of Sep 27, 2026Companies by employee count
Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 1,441 companies.
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among IT services firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in London, United Kingdom whose own description of what they do matches “IT services firms”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names IT services firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among IT services firms, and records with no verified work email. Companies headquartered outside London are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 4,037 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 27, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
IT services firms by metro in the United Kingdom
- IT services firms in London1441
- IT services firms in Manchester98
- IT services firms in Birmingham83
- IT services firms in Bristol59
- IT services firms in Glasgow53
- IT services firms in Leeds46
- IT services firms in Reading44
- IT services firms in Edinburgh42
- IT services firms in Sheffield41
- IT services firms in Milton Keynes40
- IT services firms in Liverpool36
- IT services firms in Nottingham34
- IT services firms in Slough33
- IT services firms in Cambridge32
- IT services firms in Leicester31
- IT services firms in Bournemouth27
- IT services firms in Derby26
- IT services firms in Harrow26
- IT services firms in Northampton25
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names IT services firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many IT services firms are there based in London, United Kingdom?
RevenueBase identified 1,441 IT services firms headquartered in London, United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
NSC Global, headquartered in London, tops this list with the largest team on record.
Which city has the most IT services firms?
London leads with 1441 headquartered companies, followed by Manchester (98) and Birmingham (83).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 4,037 verified decision-maker contacts tracked across these 1,441 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 27, 2026.
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IT services firms by geography
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.