Company lists · Data refreshed September 2026

Top 24 IT services and consulting firms based in London, United Kingdom

Name: IT services and consulting firms based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 27, 2026 4,477 companies tracked

RevenueBase identified 4,477 IT services and consulting firms headquartered in London, United Kingdom as of September 2026 and tracks 483,316 professional contacts across them, including 171,196 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers IT services and consulting 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 27, 2026 86% judged on-target in blind review

4,477Companies

483,316Contacts tracked

171,196Verified emails

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The 24 largest IT services and consulting firms based in London, United Kingdom

Ranked by team size

Top 24 of 4,477 IT services and consulting firms based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 27, 2026. RevenueBase Smart Search rates how each company's information relates to IT services and consulting firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	EY	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	10001+	375,085 contacts →
	Indirect evidence “EY is building a better working world by creating new value for clients, people, society, the planet, while building trust in the capital markets.” Source: RevenueBase Database · checked Sep 27, 2026
2	Endava	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	10001+	9,653 contacts →
	Indirect evidence “For over two decades, we have been harnessing technology to drive meaningful change.” Source: RevenueBase Database · checked Sep 27, 2026
3	CAPCO	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	5,001-10,000	7,396 contacts →
	Indirect evidence “Capco, a Wipro company, is a global technology and management consultancy specializing in driving digital transformation in the financial services industry.” Source: RevenueBase Database · checked Sep 27, 2026
4	Computer Futures	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	501-1,000	2,673 contacts →
	Indirect evidence “Building tomorrow’s tech landscape together Computer Futures is a Technology specialist, part of SThree, the global STEM workforce consultancy.” Source: RevenueBase Database · checked Sep 27, 2026
5	Baringa	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	2,179 contacts →
	Partial evidence “Baringa is a global consulting firm that helps leaders drive meaningful change and create value.” Source: RevenueBase Database · checked Sep 27, 2026
6	Avance Consulting	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	501-1,000	1,927 contacts →
	Partial evidence “Avance Consulting is a global organization focused on delivering innovative talent solution services to some of the most renowned companies in the world, across industries that…” Source: RevenueBase Database · checked Sep 27, 2026
7	Nashtech	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	1,611 contacts →
	Indirect evidence “We are experts in technology, delivering smart solutions that solve business challenges and create value.” Source: RevenueBase Database · checked Sep 27, 2026
8	CSC UKI	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	10001+	1,569 contacts →
	Partial evidence “HPE Enterprise Services and CSC are now @DXCTechnology, the leading independent, end-to-end #IT services company.” Source: RevenueBase Database · checked Sep 27, 2026
9	Noventiq	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	5,001-10,000	1,508 contacts →
	Indirect evidence “Noventiq (Noventiq Holdings PLC) is a leading global solutions and services provider in digital transformation and cybersecurity, headquartered in London.” Source: RevenueBase Database · checked Sep 27, 2026
10	K2 Partnering Solutions	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	1,417 contacts →
	Indirect evidence “K2 Partnering Solutions is a global provider of unique end-to-end consultative solutions in the enterprise applications, AI, and cloud space.” Source: RevenueBase Database · checked Sep 27, 2026
11	JLT Group	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	n/a	1,361 contacts →
	Indirect evidence “As of April 1, 2019, JLT Group is now part of Marsh & McLennan Companies (MMC).” Source: RevenueBase Database · checked Sep 27, 2026
12	Genisys Group	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	1,178 contacts →
	Indirect evidence “Genisys Group is a new age global information technology and business process services company.” Source: RevenueBase Database · checked Sep 27, 2026
13	Equal Experts	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	1,172 contacts →
	Indirect evidence “We are honoured to be recognised as one of the Top 10 Best Places to Work in the UK for the third year running, according to Glassdoor’s prestigious 2026 list.” Source: RevenueBase Database · checked Sep 27, 2026
14	NSC Global	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	1,039 contacts →
	Indirect evidence “Global business doesn’t have to be complicated.” Source: RevenueBase Database · checked Sep 27, 2026
15	Delta Capita	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	976 contacts →
	Partial evidence “Delta Capita is a leading global Capital Markets consulting, managed services, and technology provider with a unique combination of experience in financial services and capability…” Source: RevenueBase Database · checked Sep 27, 2026
16	Advania UK	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	910 contacts →
	Indirect evidence “We empower people to create sustainable value with the clever use of technology.” Source: RevenueBase Database · checked Sep 27, 2026
17	KERV	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	501-1,000	742 contacts →
	Indirect evidence “Kerv exists to use the power of technology for good: for our customers, our people, our communities and the planet.” Source: RevenueBase Database · checked Sep 27, 2026
18	Huxley	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	201-500	736 contacts →
	Partial evidence “Shaping the future of finance Huxley is an IT specialist, part of SThree, the global STEM workforce consultancy.” Source: RevenueBase Database · checked Sep 27, 2026
19	VML Enterprise Solutions	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	5,001-10,000	697 contacts →
	Indirect evidence “Follow us now at WPP Enterprise Solutions, WPP’s global business transformation unit, designing, building and operating the growth systems that competitive businesses rely on.” Source: RevenueBase Database · checked Sep 27, 2026
20	Excis Compliance	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	616 contacts →
	Partial evidence “Excis is a trusted global IT services company, delivering agile, multilingual support across 150+ countries.” Source: RevenueBase Database · checked Sep 27, 2026
21	Acuvate	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	201-500	545 contacts →
	Indirect evidence “At Acuvate, we empower enterprises to accelerate their Next gen transformation journeys with an AI-First approach.” Source: RevenueBase Database · checked Sep 27, 2026
22	Alten LTD - UK	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	10001+	529 contacts →
	Partial evidence “We are a leading Engineering and IT consultancy operating across all sectors in 30 different countries.” Source: RevenueBase Database · checked Sep 27, 2026
23	Mazars In The UK	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	1,001-5,000	505 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 27, 2026
24	Hitachi Solutions UK	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	501-1,000	422 contacts →
	Indirect evidence “Our team of world-class professionals across the globe work together to innovate and enable sustainable business transformation.” Source: RevenueBase Database · checked Sep 27, 2026

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 and consulting 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 and consulting firms.
Partial evidence: Its own public description names part of IT services and consulting 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 and consulting 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 24 of 4,477 IT services and consulting firms based in London, United Kingdom

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IT services and consulting firms based in London, United Kingdom at a glance

As of Sep 27, 2026

35.4%Verified-email coverage

108.0Average contacts per company

1-10Median size (employees)

Sep 27, 2026Page data refreshed

Companies by employee count

1-10

2,633

11-50

1,187

51-200

433

201-500

103

501-1,000

1,001-5,000

5,001-10,000

10001+

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 4,477 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 and consulting 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 and consulting 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 and consulting 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 and consulting 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, 171,196 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 and consulting firms by metro in the United Kingdom

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 and consulting 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 and consulting firms are there based in London, United Kingdom?

RevenueBase identified 4,477 IT services and consulting 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?

EY, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most IT services and consulting firms?

London leads the United Kingdom with 4,477 headquartered companies, followed by Manchester (271) and Birmingham (187).

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 171,196 verified decision-maker contacts tracked across these 4,477 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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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.