Company lists · Data refreshed September 2026

Top 25 HR outsourcing companies worldwide

RevenueBase identified 27,208 HR outsourcing companies worldwide as of September 2026 and tracks 716,062 professional contacts across them, including 148,631 with verified work emails and 97,237 with mobile numbers. The United States is the largest market and Sao Paulo the largest hub.

This list covers HR outsourcing 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 3, 2026. Country and city lists for HR outsourcing 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 HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 3, 2026 86% judged on-target in blind review
27,208Companies
716,062Contacts tracked
148,631Verified emails
97,237Mobile numbers
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The 25 largest HR outsourcing companies worldwide

Ranked by team size
Top 25 of 27,208 HR outsourcing companies worldwide, ranked by team size, largest first. Data refreshed Sep 3, 2026. RevenueBase Smart Search rates how each company's information relates to HR outsourcing 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceZurich, SwitzerlandHQ checked Sep 3, 202610001+139,746 contacts →

Indirect evidence

“Perfect placements.”

Source: RevenueBase Database · checked Sep 3, 2026
2Indirect evidenceRoseland, United StatesHQ checked Sep 3, 202610001+84,254 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 3, 2026
3Partial evidenceRochester, NY, United StatesHQ checked Sep 3, 202610001+17,921 contacts →

Partial 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 3, 2026
4Indirect evidenceJacksonville, United StatesHQ checked Sep 3, 202610001+12,698 contacts →

Indirect evidence

“At LHH, we believe work should be meaningful, fulfilling, and connected.”

Source: RevenueBase Database · checked Sep 3, 2026
5Indirect evidenceOklahoma City, OK, United StatesHQ checked Sep 3, 202610001+12,667 contacts →

Indirect evidence

“Founded in 1983 and corporately headquartered in Oklahoma City, Express Employment International supports the Express Employment Professionals franchise and related brands.”

Source: RevenueBase Database · checked Sep 3, 2026
6Indirect evidenceThe Woodlands, TX, United StatesHQ checked Sep 3, 20265,001-10,0005,553 contacts →

Indirect evidence

“With over 30 years as a global people, payroll, and technology leader, Strada specializes in removing complexity to simplify workforce management.”

Source: RevenueBase Database · checked Sep 3, 2026
7Indirect evidenceLondon, CA, United KingdomHQ checked Sep 3, 20261,001-5,0004,626 contacts →

Indirect evidence

“Robert Walters is the world’s most trusted talent solutions business.”

Source: RevenueBase Database · checked Sep 3, 2026
8Partial evidenceDublin, CA, United StatesHQ checked Sep 3, 20261,001-5,0004,102 contacts →

Partial evidence

“TriNet (NYSE: TNET) provides small and medium-size businesses (SMBs) with full-service HR solutions tailored by industry.”

Source: RevenueBase Database · checked Sep 3, 2026
9Indirect evidenceSan Francisco, CO, United StatesHQ checked Sep 3, 20261,001-5,0003,554 contacts →

Indirect evidence

“Gusto has been growing the small business economy for 15+ years.”

Source: RevenueBase Database · checked Sep 3, 2026
10Indirect evidenceMadrid, SpainHQ checked Sep 3, 20261,001-5,0003,068 contacts →

Indirect evidence

“Randstad es la empresa líder en España en soluciones de Recursos Humanos, haciendo posible que cada día personas en nuestro país tengan un empleo.”

Source: RevenueBase Database · checked Sep 3, 2026
11Indirect evidenceHanover, United StatesHQ checked Sep 3, 20261,001-5,0002,930 contacts →

Indirect evidence

“At Allegis Global Solutions (AGS), we’re in the human enterprise business.”

Source: RevenueBase Database · checked Sep 3, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 3, 20261,001-5,0002,730 contacts →

Partial evidence

“At Alight | NGA Human Resources our mission is to make HR work better.”

Source: RevenueBase Database · checked Sep 3, 2026
13Indirect evidenceAntwerp, BelgiumHQ checked Sep 3, 20265,001-10,0002,554 contacts →

Indirect evidence

“We spark success at the heart of your business so you and your people can thrive.”

Source: RevenueBase Database · checked Sep 3, 2026
14Indirect evidenceHanover, United StatesHQ checked Sep 3, 20261,001-5,0002,451 contacts →

Indirect evidence

“Aston Carter provides world-class corporate talent solutions to thousands of clients across the globe.”

Source: RevenueBase Database · checked Sep 3, 2026
15Indirect evidenceCesson-Sevigne, FranceHQ checked Sep 3, 202610001+2,370 contacts →

Indirect evidence

“Since 1986, the development of Samsic has been entirely due to the skills of the 70 mens and women who make up our company.”

Source: RevenueBase Database · checked Sep 3, 2026
16Partial evidenceParis La Défense, IL, FranceHQ checked Sep 3, 20261,001-5,0002,333 contacts →

Partial evidence

“HR Path, an expert, and a major player in Human Resources, helps companies for who the human experience is essential to their digital transformation.”

Source: RevenueBase Database · checked Sep 3, 2026
17Indirect evidenceAtlanta, GA, United StatesHQ checked Sep 3, 202610001+1,948 contacts →

Indirect evidence

“Remedy Intelligent Staffing is a nationwide professional staffing organization with more than 50 years of recruiting and selection expertise to match job candidates with positions…”

Source: RevenueBase Database · checked Sep 3, 2026
18Indirect evidenceDublin 4, IrelandHQ checked Sep 3, 202610001+1,835 contacts →

Indirect evidence

“Cpl is a global provider of talent solutions to startup companies, multinationals, and SMEs in every sector from Pharmaceuticals to Fund Accounting.”

Source: RevenueBase Database · checked Sep 3, 2026
19Partial evidenceMunich, GermanyHQ checked Sep 3, 20261,001-5,0001,803 contacts →

Partial 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 3, 2026
20Indirect evidenceTorino, ItalyHQ checked Sep 3, 2026501-1,0001,772 contacts →

Indirect evidence

“L’Italia è piena di talenti: il nostro lavoro è riconoscerli!” Synergie Italia S.p.A.”

Source: RevenueBase Database · checked Sep 3, 2026
21Partial evidenceMilan, ItalyHQ checked Sep 3, 20265,001-10,0001,712 contacts →

Partial evidence

“Gi Group Holding is a global ecosystem of integrated HR Services that aims at evolving the Labour Market by creating sustainable, social and economical value, emphasising the…”

Source: RevenueBase Database · checked Sep 3, 2026
22Indirect evidenceBristol, United KingdomHQ checked Sep 3, 20261,001-5,0001,457 contacts →

Indirect evidence

“Zellis helps organisations unlock better outcomes by creating exceptional experiences for their people.”

Source: RevenueBase Database · checked Sep 3, 2026
23Indirect evidenceSydney, AustraliaHQ checked Sep 3, 20261,001-5,0001,439 contacts →

Indirect evidence

“Established as Australia’s first firm of organisational psychologists, Chandler Macleod has become the market leading provider of fully-integrated human resource services…”

Source: RevenueBase Database · checked Sep 3, 2026
24Indirect evidenceMilano, ItalyHQ checked Sep 3, 20261,001-5,0001,436 contacts →

Indirect evidence

“Grafton is one of the largest recruitment companies worldwide.”

Source: RevenueBase Database · checked Sep 3, 2026
25Indirect evidenceCiudad Autónoma De Buenos Aires, ArgentinaHQ checked Sep 3, 202610001+1,429 contacts →

Indirect evidence

“Desde su formación en 1997, GRUPO GESTIÓN se afianzó en el país, a través de sus diferentes Unidades de Negocio, como uno de los líderes de Compañías especializadas en la…”

Source: RevenueBase Database · checked Sep 3, 2026

Showing 25 of 27,208 HR outsourcing companies worldwide

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HR outsourcing companies worldwide at a glance

As of Sep 3, 2026
20.8%Verified-email coverage
13.6%Mobile-number coverage
26.3Average contacts per company
1-10Median size (employees)
2.7%Largest-city concentration · Sao Paulo
Sep 3, 2026Page data refreshed

Companies by employee count

1-10
17,578
11-50
5,583
51-200
2,186
201-500
821
501-1,000
371
1,001-5,000
359
5,001-10,000
72
10001+
63

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 HR outsourcing 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
41 countries, largest first: the United States, Brazil, the United Kingdom, France, Mexico, Canada, the Netherlands, Australia, Argentina, Germany and 31 more. Country and city lists for HR outsourcing companies are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “HR outsourcing 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 HR outsourcing 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 HR outsourcing 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, 148,631 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 3, 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.

HR outsourcing companies by location

110 lists · largest first

Every HR outsourcing 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 HR outsourcing 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 HR outsourcing companies are there worldwide?

RevenueBase identified 27,208 HR outsourcing 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?

Adecco, headquartered in Bilbo, tops this list with the largest team on record.

Which country has the most HR outsourcing companies?

The United States leads with 7,071 companies, followed by Brazil (3,269) and the United Kingdom (2,192). Every HR outsourcing companies list by country and city is linked on this page.

Which city has the most HR outsourcing companies?

Sao Paulo leads with 733 headquartered companies, followed by London (570) and Paris (359).

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 148,631 verified decision-maker contacts tracked across these 27,208 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 3, 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.