Company lists · Data refreshed September 2026

Top 24 Consulting firms based in London, United Kingdom

Name: 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 8, 2026 6,777 companies tracked

RevenueBase identified 6,777 consulting firms headquartered in London, United Kingdom as of September 2026 and tracks 102,822 professional contacts across them, including 41,209 with verified work emails and 9,198 with mobile numbers. London is the largest hub.

This list covers 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 8, 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 8, 2026 86% judged on-target in blind review

6,777Companies

102,822Contacts tracked

41,209Verified emails

9,198Mobile numbers

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The 24 largest consulting firms based in London, United Kingdom

Ranked by team size

Top 24 of 6,777 consulting firms based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 8, 2026. RevenueBase Smart Search rates how each company's information relates to 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-Parthenon	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	10001+	17,070 contacts →
	Indirect evidence “Our unique combination of transformative strategy, transactions and corporate finance delivers real-world value – solutions that work in practice, not just on paper.” Source: RevenueBase Database · checked Sep 8, 2026
2	Acuity Knowledge Partners	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	5,001-10,000	5,009 contacts →
	Indirect evidence “Acuity Knowledge Partners (Acuity) is a leading provider of bespoke research, analytics and technology solutions to the financial services sector, including asset managers…” Source: RevenueBase Database · checked Sep 8, 2026
3	Baringa	Strong evidence	London, United KingdomHQ checked Sep 8, 2026	1,001-5,000	2,179 contacts →
	Strong evidence “Baringa is a global consulting firm that helps leaders drive meaningful change and create value.” Source: RevenueBase Database · checked Sep 8, 2026
4	Antal International	Indirect evidence	London, United KingdomHQ checked Sep 8, 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 8, 2026
5	Avance Consulting	Strong evidence	London, United KingdomHQ checked Sep 8, 2026	501-1,000	1,927 contacts →
	Strong 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 8, 2026
6	Barnett Waddingham	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	1,001-5,000	1,331 contacts →
	Indirect evidence “We are a leading UK professional services consultancy at the forefront of risk, pensions, investment and insurance.” Source: RevenueBase Database · checked Sep 8, 2026
7	Efficio	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	1,001-5,000	1,304 contacts →
	Indirect evidence “Efficio is a global leader in procurement and supply chain management and transformation.” Source: RevenueBase Database · checked Sep 8, 2026
8	Blackmont Consulting	Strong evidence	London, United KingdomHQ checked Sep 8, 2026	201-500	1,221 contacts →
	Strong evidence “Blackmont Consulting provides 100% free advisory services to NGO´s, NPO´s and start-ups.” Source: RevenueBase Database · checked Sep 8, 2026
9	Oc&c Strategy Consultants	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	501-1,000	1,011 contacts →
	Indirect 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 8, 2026
10	Delta Capita	Strong evidence	London, United KingdomHQ checked Sep 8, 2026	1,001-5,000	976 contacts →
	Strong 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 8, 2026
11	PKF Littlejohn	Indirect evidence	London, United KingdomHQ checked Sep 8, 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 8, 2026
12	Strategy Insights	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	51-200	528 contacts →
	Indirect evidence “Strategy Insights is a specialist business and economic development consultancy.” Source: RevenueBase Database · checked Sep 8, 2026
13	Mazars In The UK	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	1,001-5,000	505 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 8, 2026
14	Frontier Economics	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	201-500	477 contacts →
	Indirect evidence “We help companies with their biggest challenges – market strategies, regulatory reviews, competition inquiries.” Source: RevenueBase Database · checked Sep 8, 2026
15	Analysys Mason	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	201-500	459 contacts →
	Indirect 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 8, 2026
16	Transearch	Strong evidence	London, United KingdomHQ checked Sep 8, 2026	501-1,000	450 contacts →
	Strong evidence “TRANSEARCH International is a global executive search and leadership consulting organisation.” Source: RevenueBase Database · checked Sep 8, 2026
17	GRS	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	51-200	425 contacts →
	Indirect 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 8, 2026
18	Hirexa Solutions	Indirect evidence	London, United KingdomHQ checked Sep 8, 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 8, 2026
19	Softwire	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	201-500	360 contacts →
	Indirect evidence “Softwire exists to help organisations use technology to deliver meaningful outcomes and a positive impact for themselves, their users and the world.” Source: RevenueBase Database · checked Sep 8, 2026
20	Kovaion Consulting	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	201-500	353 contacts →
	Indirect evidence “Kovaion is a global AI-powered solutions and innovation company focused on Oracle technologies, enterprise applications, intelligent automation, and digital transformation.” Source: RevenueBase Database · checked Sep 8, 2026
21	Emergn	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	501-1,000	351 contacts →
	Indirect evidence “Emergn is a global technology and management consultancy built on a simple conviction: the only sustainable competitive advantage is the way you work.” Source: RevenueBase Database · checked Sep 8, 2026
22	PSD Group	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	51-200	335 contacts →
	Indirect 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 8, 2026
23	Ubique Systems	Strong evidence	London, United KingdomHQ checked Sep 8, 2026	501-1,000	333 contacts →
	Strong 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 8, 2026
24	Mercer UK	Indirect evidence	London, United KingdomHQ checked Sep 8, 2026	10001+	329 contacts →
	Indirect evidence “At Mercer, A Marsh business, we’re helping our clients realize their investment objectives, shape the future of work, and enhance health and retirement outcomes for their people.” Source: RevenueBase Database · checked Sep 8, 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: 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 consulting firms.
Partial evidence: Its own public description names part of consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name 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 6,777 consulting firms based in London, United Kingdom

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Consulting firms based in London, United Kingdom at a glance

As of Sep 8, 2026

40.1%Verified-email coverage

8.9%Mobile-number coverage

15.2Average contacts per company

1-10Median size (employees)

98.7%Largest-city concentration · London

Sep 8, 2026Page data refreshed

Companies by employee count

1-10

5,024

11-50

1,299

51-200

304

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Freshness & accuracy

How recently the business emails were verified and the company information checked

Email last verified

Median 11.0d

37,1980–30

3,60631–60

2761–90

4590–180

333180+

Company record updated

Median 59.0d

00–30

58,53531–60

31,36761–90

7,06190–180

5,859180+

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 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 “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 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 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, 41,209 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 8, 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.

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 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 consulting firms are there based in London, United Kingdom?

RevenueBase identified 6,777 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-Parthenon, headquartered in London, tops this list with the largest team on record.

Which city has the most consulting firms?

London leads with 6692 headquartered companies, followed by Manchester (362) and Birmingham (213).

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 41,209 verified decision-maker contacts tracked across these 6,777 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 8, 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.