Company lists · Data refreshed September 2026

Top 25 Consultancy companies based in London, United Kingdom

Name: Consultancy companies based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 24, 2026 6,437 companies tracked

RevenueBase identified 6,437 consultancy companies headquartered in London, United Kingdom as of September 2026 and tracks 67,290 professional contacts across them, including 26,754 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers consultancy companies 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 24, 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 24, 2026 86% judged on-target in blind review

6,437Companies

67,290Contacts tracked

26,754Verified emails

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The 25 largest consultancy companies based in London, United Kingdom

Ranked by team size

Top 25 of 6,437 consultancy companies based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 24, 2026. RevenueBase Smart Search rates how each company's information relates to consultancy companies: 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	MACE	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	5,001-10,000	8,458 contacts →
	Indirect evidence “Mace Consult launched as a new and independent business on 5 March 2026, through a carve-out from Mace Group.” Source: RevenueBase Database · checked Sep 24, 2026
2	Baringa	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	1,001-5,000	2,179 contacts →
	Indirect evidence “Baringa is a global consulting firm that helps leaders drive meaningful change and create value.” Source: RevenueBase Database · checked Sep 24, 2026
3	Antal International	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	1,001-5,000	1,979 contacts →
	Indirect evidence “Antal International is a global executive search organisation with over 130 offices in more than 30 countries.” Source: RevenueBase Database · checked Sep 24, 2026
4	Barnett Waddingham	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	1,001-5,000	1,331 contacts →
	Strong evidence “We are a leading UK professional services consultancy at the forefront of risk, pensions, investment and insurance.” Source: RevenueBase Database · checked Sep 24, 2026
5	Blackmont Consulting	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	1,221 contacts →
	Indirect evidence “Blackmont Consulting provides 100% free advisory services to NGO´s, NPO´s and start-ups.” Source: RevenueBase Database · checked Sep 24, 2026
6	Oc&c Strategy Consultants	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	501-1,000	1,011 contacts →
	Strong evidence “At OC & C Strategy Consultants we have more than 35 years of experience at unpicking the most complex business challenges with simple, uncommon sense™.” Source: RevenueBase Database · checked Sep 24, 2026
7	PKF Littlejohn	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	501-1,000	702 contacts →
	Indirect evidence “We are a fast-growing firm of accountants and business advisers based in London’s Canary Wharf, Leeds and in Manchester.” Source: RevenueBase Database · checked Sep 24, 2026
8	Waterman Group	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	1,001-5,000	563 contacts →
	Strong evidence “Waterman Group is a multidisciplinary consultancy providing sustainable solutions to meet the planning, engineering design and project delivery needs of the property…” Source: RevenueBase Database · checked Sep 24, 2026
9	Alten LTD - UK	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	10001+	529 contacts →
	Strong evidence “We are a leading Engineering and IT consultancy operating across all sectors in 30 different countries.” Source: RevenueBase Database · checked Sep 24, 2026
10	Strategy Insights	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	51-200	528 contacts →
	Strong evidence “Strategy Insights is a specialist business and economic development consultancy.” Source: RevenueBase Database · checked Sep 24, 2026
11	STEER	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	524 contacts →
	Indirect evidence “Complex challenges.” Source: RevenueBase Database · checked Sep 24, 2026
12	Broadstone	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	501-1,000	497 contacts →
	Strong evidence “Broadstone is a leading, independent UK consultancy delivering expert advice to employers, insurers, pension scheme trustees and lenders.” Source: RevenueBase Database · checked Sep 24, 2026
13	Aspens Services LTD	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	5,001-10,000	497 contacts →
	Indirect evidence “We are a catering company who specialise in the education sector.” Source: RevenueBase Database · checked Sep 24, 2026
14	Analysys Mason	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	459 contacts →
	Strong evidence “Analysys Mason is the leading specialist consultancy, creating lasting value in technology-intensive industries, including telecoms, digital infrastructure, software, IT services…” Source: RevenueBase Database · checked Sep 24, 2026
15	GRS	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	51-200	425 contacts →
	Strong evidence “The GRS Group is an international executive search consultancy whose services include retained search, contingency search, advertised selection and interim solutions.” Source: RevenueBase Database · checked Sep 24, 2026
16	Hirexa Solutions	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	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 24, 2026
17	CPC Project Services	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	342 contacts →
	Strong evidence “CPC is an award-winning project management, cost management and building surveying consultancy.” Source: RevenueBase Database · checked Sep 24, 2026
18	PSD Group	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	51-200	335 contacts →
	Strong evidence “PSD is a leading international executive recruitment consultancy, specialising in executive, management and board level recruitment with over 35 years of experience.” Source: RevenueBase Database · checked Sep 24, 2026
19	Ubique Systems	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	501-1,000	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 24, 2026
20	Cumming Group UK & Europe	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	501-1,000	324 contacts →
	Indirect evidence “At Cumming Group, we are passionate about helping our clients execute large-scale, complex projects on-time and within budget.” Source: RevenueBase Database · checked Sep 24, 2026
21	Cartesian	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	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 24, 2026
22	Timeplan Education Group Limited	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	51-200	297 contacts →
	Indirect evidence “At TimePlan Education we understand that teaching is not just a job, it’s a calling.” Source: RevenueBase Database · checked Sep 24, 2026
23	Elixirr	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	501-1,000	275 contacts →
	Indirect evidence “An award-winning global consulting firm working with clients across a diverse range of markets, industries and geographies.” Source: RevenueBase Database · checked Sep 24, 2026
24	Transform	Indirect evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	255 contacts →
	Indirect evidence “Transform is a fresh alternative to Big Consulting.” Source: RevenueBase Database · checked Sep 24, 2026
25	Sheffield Haworth	Strong evidence	London, United KingdomHQ checked Sep 24, 2026	201-500	244 contacts →
	Strong evidence “Sheffield Haworth is a global consultancy founded in 1993.” Source: RevenueBase Database · checked Sep 24, 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: consultancy companies. 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 consultancy companies.
Partial evidence: Its own public description names part of consultancy companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name consultancy companies. 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 6,437 consultancy companies based in London, United Kingdom

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Consultancy companies based in London, United Kingdom at a glance

As of Sep 24, 2026

39.8%Verified-email coverage

10.5Average contacts per company

1-10Median size (employees)

Sep 24, 2026Page data refreshed

Companies by employee count

1-10

4,819

11-50

1,227

51-200

274

201-500

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 6,437 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 consultancy companies, 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 “consultancy companies”. 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 consultancy companies), 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 consultancy companies, 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, 26,754 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 24, 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.

Consultancy companies 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 consultancy companies, 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 consultancy companies are there based in London, United Kingdom?

RevenueBase identified 6,437 consultancy companies 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?

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

Which city in the United Kingdom has the most consultancy companies?

London leads the United Kingdom with 6,437 headquartered companies, followed by Manchester (502) and Bristol (278).

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 26,754 verified decision-maker contacts tracked across these 6,437 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 24, 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.