Company lists · Data refreshed September 2026

Top 25 Professional service companies worldwide

Name: Professional service companies worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 20, 2026 25,915 companies tracked

RevenueBase identified 25,915 professional service companies worldwide as of September 2026 and tracks 891,361 professional contacts across them, including 311,132 with verified work emails. The United States is the largest market and Sao Paulo the largest hub.

This list covers professional service companies worldwide, 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 20, 2026. Country and city lists for professional service companies follow the table.

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 RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review

25,915Companies

891,361Contacts tracked

311,132Verified emails

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The 25 largest professional service companies worldwide

Ranked by team size

Top 25 of 25,915 professional service companies worldwide, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to professional service 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	Deloitte	Indirect evidence	United StatesHQ checked Sep 20, 2026	10001+	480,083 contacts →
	Indirect evidence “Deloitte drives progress.” Source: RevenueBase Database · checked Sep 20, 2026
2	Kpmg India	Strong evidence	Gurugram, IndiaHQ checked Sep 20, 2026	10001+	28,997 contacts →
	Strong evidence “KPMG entities in India are established under the laws of India and are owned and managed (as the case may be) by established Indian professionals.” Source: RevenueBase Database · checked Sep 20, 2026
3	Kpmg Deutschland	Strong evidence	Berlin, GermanyHQ checked Sep 20, 2026	10001+	8,886 contacts →
	Strong evidence “KPMG is a network of professional firms with about employees in 146 countries and territories.” Source: RevenueBase Database · checked Sep 20, 2026
4	Protiviti	Indirect evidence	Menlo Park, CA, United StatesHQ checked Sep 20, 2026	5,001-10,000	8,779 contacts →
	Indirect evidence “Protiviti is a global consulting firm that delivers deep expertise, objective insights, a tailored approach and unparalleled collaboration to help leaders confidently face the…” Source: RevenueBase Database · checked Sep 20, 2026
5	CBIZ	Strong evidence	Independence, OH, United StatesHQ checked Sep 20, 2026	10001+	6,369 contacts →
	Strong evidence “CBIZ, Inc.(NYSE: CBZ) is a leading professional services advisor to middle-market businesses nationwide.” Source: RevenueBase Database · checked Sep 20, 2026
6	Management Solutions	Indirect evidence	Madrid, SpainHQ checked Sep 20, 2026	1,001-5,000	4,468 contacts →
	Indirect evidence “Management Solutions is a leading provider of business consulting services for regulated industries.” Source: RevenueBase Database · checked Sep 20, 2026
7	Eisneramper	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	1,001-5,000	4,199 contacts →
	Indirect evidence “EisnerAmper, one of the largest business consulting firms in the world, is comprised of EisnerAmper LLP, a licensed independent CPA firm that provides client attest services; and…” Source: RevenueBase Database · checked Sep 20, 2026
8	PWC Luxembourg	Strong evidence	LuxembourgHQ checked Sep 20, 2026	1,001-5,000	3,413 contacts →
	Strong evidence “PwC Luxembourg is the largest professional services firm in Luxembourg with over 3,600 people employed from 90 different countries.” Source: RevenueBase Database · checked Sep 20, 2026
9	In Extenso	Indirect evidence	Lyon, FranceHQ checked Sep 20, 2026	5,001-10,000	3,278 contacts →
	Indirect evidence “Crée en 1991 In Extenso est l’un des leaders de l’expertise comptable en France.” Source: RevenueBase Database · checked Sep 20, 2026
10	Citrin Cooperman	Strong evidence	New York, United StatesHQ checked Sep 20, 2026	1,001-5,000	2,996 contacts →
	Strong evidence “Citrin Cooperman is one of the nation’s largest and fastest-growing professional services firms.” Source: RevenueBase Database · checked Sep 20, 2026
11	PWC Malaysia	Indirect evidence	Kuala Lumpur, MalaysiaHQ checked Sep 20, 2026	1,001-5,000	2,858 contacts →
	Indirect evidence “At PwC, we measure success by having a positive reputation.” Source: RevenueBase Database · checked Sep 20, 2026
12	Uhy-Us	Strong evidence	New York, NY, United StatesHQ checked Sep 20, 2026	1,001-5,000	2,035 contacts →
	Strong evidence “UHY is one of the nation’s largest professional services firms providing audit, tax, consulting and advisory services to clients primarily in the dynamic middle market.” Source: RevenueBase Database · checked Sep 20, 2026
13	J.S. Held LLC	Indirect evidence	Jericho, NY, PalestineHQ checked Sep 20, 2026	1,001-5,000	1,954 contacts →
	Indirect evidence “J.S.” Source: RevenueBase Database · checked Sep 20, 2026
14	PWC Norway	Indirect evidence	Oslo, NorwayHQ checked Sep 20, 2026	1,001-5,000	1,824 contacts →
	Indirect evidence “PwC er et ledende globalt kompetansehus som bidrar med kunnskap, innsikt og verdiskapning.” Source: RevenueBase Database · checked Sep 20, 2026
15	Kpmg Poland	Indirect evidence	Warsaw, PolandHQ checked Sep 20, 2026	1,001-5,000	1,696 contacts →
	Indirect evidence “KPMG jest globalną organizacją niezależnych firm świadczących profesjonalne usługi z zakresu audytu, doradztwa podatkowego, finansowego, prawnego oraz consultingu.” Source: RevenueBase Database · checked Sep 20, 2026
16	Sikich	Strong evidence	Chicago, IL, United StatesHQ checked Sep 20, 2026	1,001-5,000	1,688 contacts →
	Strong evidence “Sikich offers the public and private sectors a diverse platform of professional services across consulting, technology, and compliance.” Source: RevenueBase Database · checked Sep 20, 2026
17	JTC Group	Strong evidence	St Helier, JerseyHQ checked Sep 20, 2026	1,001-5,000	1,574 contacts →
	Strong evidence “JTC is a publicly listed, global professional services business with deep expertise in fund, corporate and private client services.” Source: RevenueBase Database · checked Sep 20, 2026
18	BDO Norge	Indirect evidence	Oslo, NorwayHQ checked Sep 20, 2026	1,001-5,000	1,530 contacts →
	Indirect evidence “We see great value in having a local presence and roots, factors which enable us to work closely with our clients.” Source: RevenueBase Database · checked Sep 20, 2026
19	BDO In Indonesia	Strong evidence	Jakarta, IndonesiaHQ checked Sep 20, 2026	501-1,000	1,508 contacts →
	Strong evidence “BDO is the leading provider of professional services within the mid-tier of our profession.” Source: RevenueBase Database · checked Sep 20, 2026
20	RSM Ebner Stolz	Indirect evidence	Stuttgart, GermanyHQ checked Sep 20, 2026	1,001-5,000	1,442 contacts →
	Indirect evidence “Wollen Sie jemanden, der Sie auch beim Sprung in neue Märkte und bei allen anstehenden Herausforderungen begleitet?” Source: RevenueBase Database · checked Sep 20, 2026
21	EXL Services LTD	Indirect evidence	n/a	n/a	1,373 contacts →
	Indirect evidence “Established in 1994, we provide a blend of business strategy, marketing services, behavioural change and executive coaching services and techniques to help grow the business of…” Source: RevenueBase Database · checked Sep 20, 2026
22	Rehmann	Strong evidence	Troy, MI, United StatesHQ checked Sep 20, 2026	501-1,000	1,323 contacts →
	Strong evidence “Rehmann is a professional advisory firm that provides accounting and assurance, business solutions and outsourcing, specialized consulting, and wealth management services.” Source: RevenueBase Database · checked Sep 20, 2026
23	Knights	Strong evidence	Newcastle-under-lyme, United KingdomHQ checked Sep 20, 2026	1,001-5,000	1,322 contacts →
	Strong evidence “We're the business people turn to for professional services everywhere across the UK.” Source: RevenueBase Database · checked Sep 20, 2026
24	BPM LLP	Indirect evidence	San Francisco, CA, United StatesHQ checked Sep 20, 2026	1,001-5,000	1,303 contacts →
	Indirect evidence “Hi there, we're BPM!” Source: RevenueBase Database · checked Sep 20, 2026
25	Mallette	Indirect evidence	Québec, QC, CanadaHQ checked Sep 20, 2026	1,001-5,000	1,268 contacts →
	Indirect evidence “Mallette compte plus de 40 bureaux solidement implantés dans plusieurs régions du Québec et regroupe plus de 1 600 ressources œuvrant dans différents secteurs d’activité.” Source: RevenueBase Database · checked Sep 20, 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: professional service 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 professional service companies.
Partial evidence: Its own public description names part of professional service companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name professional service 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 25,915 professional service companies worldwide

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Professional service companies worldwide at a glance

As of Sep 20, 2026

34.9%Verified-email coverage

34.4Average contacts per company

1-10Median size (employees)

1.9%Largest-city concentration · Sao Paulo

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

14,559

11-50

8,621

51-200

1,920

201-500

402

501-1,000

122

1,001-5,000

113

5,001-10,000

10001+

Email recency is reported on each country list linked below.

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 professional service 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.
Coverage: Every country. Country and city lists for professional service companies are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “professional service 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 professional service 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 professional service companies, and records with no verified work email.
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, 311,132 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 20, 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.

Professional service companies by location

112 lists · largest first

Every Professional service companies list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 professional service 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 professional service companies are there worldwide?

RevenueBase identified 25,915 professional service companies worldwide 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?

Deloitte, headquartered in Worldwide, tops this list with the largest team on record.

Which country has the most professional service companies?

The United States leads with 2,819 companies, followed by Brazil (2,235) and India (1,724). Every professional service companies list by country and city is linked on this page.

Which city has the most professional service companies?

Sao Paulo leads with 505 headquartered companies, followed by London (278) and Paris (276).

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 311,132 verified decision-maker contacts tracked across these 25,915 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 20, 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.