Company lists · Data refreshed September 2026

Top 25 Professional employer organizations worldwide

Name: Professional employer organizations worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 20, 2026 12,713 companies tracked

RevenueBase identified 12,713 professional employer organizations worldwide as of September 2026 and tracks 298,443 professional contacts across them, including 85,556 with verified work emails. The United States is the largest market and Sao Paulo the largest hub.

This list covers professional employer organizations 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 employer organizations 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 HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review

12,713Companies

298,443Contacts tracked

85,556Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest professional employer organizations worldwide

Ranked by team size

Top 25 of 12,713 professional employer organizations worldwide, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to professional employer organizations: 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	ADP	Indirect evidence	Roseland, NJ, United StatesHQ checked Sep 20, 2026	10001+	84,166 contacts →
	Indirect evidence “Designing better ways to work through cutting-edge products, premium services and exceptional experiences that enable people to reach their full potential.” Source: RevenueBase Database · checked Sep 20, 2026
2	Paychex	Indirect evidence	Rochester, NY, United StatesHQ checked Sep 20, 2026	10001+	17,911 contacts →
	Indirect evidence “As the future of work continues to evolve, Paychex leads the way by making complex HR, payroll, and benefits brilliantly simple.” Source: RevenueBase Database · checked Sep 20, 2026
3	Insperity	Indirect evidence	Kingwood, TX, United StatesHQ checked Sep 20, 2026	1,001-5,000	4,761 contacts →
	Indirect evidence “Since 1986, Insperity’s mission has been to help businesses succeed so communities prosper.” Source: RevenueBase Database · checked Sep 20, 2026
4	Trinet	Indirect evidence	Dublin, CA, United StatesHQ checked Sep 20, 2026	1,001-5,000	4,056 contacts →
	Indirect evidence “TriNet (NYSE: TNET) provides small and medium-size businesses (SMBs) with full-service HR solutions tailored by industry.” Source: RevenueBase Database · checked Sep 20, 2026
5	GUSTO	Indirect evidence	San Francisco, CA, United StatesHQ checked Sep 20, 2026	1,001-5,000	3,543 contacts →
	Indirect evidence “Gusto has been growing the small business economy for 15+ years.” Source: RevenueBase Database · checked Sep 20, 2026
6	NGA Human Resources, An Alight Company	Indirect evidence	London, United KingdomHQ checked Sep 20, 2026	1,001-5,000	2,734 contacts →
	Indirect evidence “At Alight \| NGA Human Resources our mission is to make HR work better.” Source: RevenueBase Database · checked Sep 20, 2026
7	SD Worx	Indirect evidence	Antwerp, BelgiumHQ checked Sep 20, 2026	5,001-10,000	2,561 contacts →
	Indirect evidence “SD Worx is your HR, Pay and Time partner in Europe.” Source: RevenueBase Database · checked Sep 20, 2026
8	Vensure Employer Solutions	Partial evidence	Chandler, AZ, United StatesHQ checked Sep 20, 2026	1,001-5,000	2,437 contacts →
	Partial evidence “VensureHR is the direct employer services business unit of Vensure Employer Solutions, the largest privately held organization in the HR technology and services sector, delivering…” Source: RevenueBase Database · checked Sep 20, 2026
9	BUK	Indirect evidence	Miguel Hidalgo, MexicoHQ checked Sep 20, 2026	1,001-5,000	2,057 contacts →
	Indirect evidence “Un software de recursos humanos para atender todas las necesidades de tus colaboradores.” Source: RevenueBase Database · checked Sep 20, 2026
10	Sopra HR Software	Indirect evidence	Courbevoie, FranceHQ checked Sep 20, 2026	1,001-5,000	1,855 contacts →
	Indirect evidence “Sopra HR Software, leader en solutions et services pour la paie et les RH, répond aux enjeux des Directions des Ressources Humaines des organisations de moyennes et grandes…” Source: RevenueBase Database · checked Sep 20, 2026
11	Personio	Indirect evidence	Munich, GermanyHQ checked Sep 20, 2026	1,001-5,000	1,786 contacts →
	Indirect evidence “Founded in 2015 and built in Europe, Personio is the Intelligent HR Platform championing every side of HR's evolution.” Source: RevenueBase Database · checked Sep 20, 2026
12	Fesco Adecco (外企德科)	Indirect evidence	上海, ChinaHQ checked Sep 20, 2026	1,001-5,000	1,687 contacts →
	Indirect evidence “FESCO Adecco is a joint-venture human resources services company combining the strengths of FESCO Group (a China 500 Company and the first Chinese company in the human resources…” Source: RevenueBase Database · checked Sep 20, 2026
13	G-P	Partial evidence	Remote First Company, MexicoHQ checked Sep 20, 2026	1,001-5,000	1,621 contacts →
	Partial evidence “G-P is your co-pilot for global employment providing HR, legal and compliance support at your fingertips so you can build teams anywhere.” Source: RevenueBase Database · checked Sep 20, 2026
14	BBSI	Strong evidence	Vancouver, WA, United StatesHQ checked Sep 20, 2026	501-1,000	1,591 contacts →
	Strong evidence “We started as a staffing company in 1972, and over the past 50 years, evolved into a Professional Employer Organization or PEO.” Source: RevenueBase Database · checked Sep 20, 2026
15	Justworks	Indirect evidence	New York, NY, United StatesHQ checked Sep 20, 2026	1,001-5,000	1,554 contacts →
	Indirect evidence “Justworks takes the busyness out of growing a business and alleviates the unknown.” Source: RevenueBase Database · checked Sep 20, 2026
16	Activos Chile	Indirect evidence	Las Condes, ChileHQ checked Sep 20, 2026	5,001-10,000	1,504 contacts →
	Indirect evidence “Somos una empresa especializada en entregar servicios integrados en el sector de recursos humanos comprometida con los procesos y necesidades de cada uno de nuestros clientes.” Source: RevenueBase Database · checked Sep 20, 2026
17	Zellis	Indirect evidence	Bristol, United KingdomHQ checked Sep 20, 2026	1,001-5,000	1,465 contacts →
	Indirect evidence “Zellis helps organisations unlock better outcomes by creating exceptional experiences for their people.” Source: RevenueBase Database · checked Sep 20, 2026
18	Buzzworks Business Services Pvt. LTD	Indirect evidence	Chennai, IndiaHQ checked Sep 20, 2026	10001+	1,275 contacts →
	Indirect evidence “With buzzworks, find the right people with the right skills at the right time.” Source: RevenueBase Database · checked Sep 20, 2026
19	Tasc Outsourcing	Indirect evidence	Dubai, United Arab EmiratesHQ checked Sep 20, 2026	10001+	1,025 contacts →
	Indirect evidence “TASC Outsourcing is a leading people solutions partner in the GCC, working at the intersection of technology, process, and people to help organisations build agile, compliant, and…” Source: RevenueBase Database · checked Sep 20, 2026
20	Akal Information Systems LTD	Indirect evidence	New Delhi, IndiaHQ checked Sep 20, 2026	1,001-5,000	1,012 contacts →
	Indirect evidence “AKAL Information Systems Ltd is a leading software and business services company with over 25 years of experience, dedicated to transform Indian Human Resource landscape through…” Source: RevenueBase Database · checked Sep 20, 2026
21	Zalaris	Indirect evidence	Oslo, NorwayHQ checked Sep 20, 2026	1,001-5,000	988 contacts →
	Indirect evidence “Simplify work life.” Source: RevenueBase Database · checked Sep 20, 2026
22	Human Quality	Indirect evidence	Monterrey, MexicoHQ checked Sep 20, 2026	1,001-5,000	874 contacts →
	Indirect evidence “At Human Quality, we are known as a leading provider of Human Resources solutions that connect top talent with companies.” Source: RevenueBase Database · checked Sep 20, 2026
23	Labournet	Indirect evidence	Johannesburg, South AfricaHQ checked Sep 20, 2026	201-500	841 contacts →
	Indirect evidence “Labournet – your strategic partner in simplifying human resource management.” Source: RevenueBase Database · checked Sep 20, 2026
24	G&a Partners	Indirect evidence	Houston, TX, United StatesHQ checked Sep 20, 2026	501-1,000	840 contacts →
	Indirect evidence “Managing HR, payroll, benefits, and compliance can stretch your team thin, and mistakes are costly.” Source: RevenueBase Database · checked Sep 20, 2026
25	OASIS	Strong evidence	West Palm Beach, FL, United StatesHQ checked Sep 20, 2026	501-1,000	828 contacts →
	Strong evidence “Oasis, A Paychex Company, is a leading Professional Employer Organization (PEO).” 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 employer organizations. 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 employer organizations.
Partial evidence: Its own public description names part of professional employer organizations, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name professional employer organizations. 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 12,713 professional employer organizations worldwide

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 85,556 reachable decision-makers.

Free signup · no credit card

View the full list →

Professional employer organizations worldwide at a glance

As of Sep 20, 2026

28.7%Verified-email coverage

23.5Average contacts per company

1-10Median size (employees)

1.0%Largest-city concentration · Sao Paulo

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

7,415

11-50

3,112

51-200

1,117

201-500

447

501-1,000

234

1,001-5,000

232

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 employer organizations, 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 employer organizations are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “professional employer organizations”. 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 employer organizations), 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 employer organizations, 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, 85,556 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 employer organizations by location

58 lists · largest first

Every Professional employer organizations 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 employer organizations, 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 employer organizations are there worldwide?

RevenueBase identified 12,713 professional employer organizations 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?

ADP, headquartered in Roseland, tops this list with the largest team on record.

Which country has the most professional employer organizations?

The United States leads with 3,309 companies, followed by India (1,303) and France (647). Every professional employer organizations list by country and city is linked on this page.

Which city has the most professional employer organizations?

Sao Paulo leads with 128 headquartered companies, followed by Mumbai (116) and London (111).

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 85,556 verified decision-maker contacts tracked across these 12,713 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.

Ready to reach these companies? Verified emails and direct dials for all 12,713 professional employer organizations worldwide. Start with a free account, no credit card.

Download this list →

Related lists

Browse the directory

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.