Company lists · Data refreshed September 2026

Top 25 HR outsourcing service providers worldwide

RevenueBase identified 26,120 HR outsourcing service providers worldwide as of September 2026 and tracks 655,255 professional contacts across them, including 142,959 with verified work emails and 82,422 with mobile numbers. The United States is the largest market and Sao Paulo the largest hub.

This list covers HR outsourcing service providers 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 30, 2026. Country and city lists for HR outsourcing service providers 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 30, 2026 86% judged on-target in blind review
26,120Companies
655,255Contacts tracked
142,959Verified emails
82,422Mobile numbers
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The 25 largest HR outsourcing service providers worldwide

Ranked by team size
Top 25 of 26,120 HR outsourcing service providers worldwide, ranked by team size, largest first. Data refreshed Sep 30, 2026. RevenueBase Smart Search rates how each company's information relates to HR outsourcing service providers: 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 30, 202610001+141,230 contacts →

Indirect evidence

“Perfect placements.”

Source: RevenueBase Database · checked Sep 30, 2026
2Indirect evidenceRoseland, NJ, United StatesHQ checked Sep 30, 202610001+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 30, 2026
3Partial evidenceRochester, NY, United StatesHQ checked Sep 30, 202610001+17,911 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 30, 2026
4Indirect evidenceJacksonville, FL, United StatesHQ checked Sep 30, 202610001+12,889 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 30, 2026
5Indirect evidenceAtlanta, GA, United StatesHQ checked Sep 30, 20261,001-5,0008,522 contacts →

Indirect evidence

“Randstad North America, Inc.”

Source: RevenueBase Database · checked Sep 30, 2026
6Indirect evidenceThe Woodlands, TX, United StatesHQ checked Sep 30, 20265,001-10,0005,585 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 30, 2026
7Indirect evidenceKingwood, TX, United StatesHQ checked Sep 30, 20261,001-5,0004,761 contacts →

Indirect evidence

“Since 1986, Insperity’s mission has been to help businesses succeed so communities prosper.”

Source: RevenueBase Database · checked Sep 30, 2026
8Partial evidenceDublin, CA, United StatesHQ checked Sep 30, 20261,001-5,0004,056 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 30, 2026
9Indirect evidenceMarina Del Rey, CA, United StatesHQ checked Sep 30, 20261,001-5,0004,000 contacts →

Indirect evidence

“PSG is a global leader in recruitment process optimization, delivering high-performance outsourced recruiting solutions that drive real business results.”

Source: RevenueBase Database · checked Sep 30, 2026
10Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 30, 20261,001-5,0003,543 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 30, 2026
11Indirect evidenceMadrid, SpainHQ checked Sep 30, 20261,001-5,0003,083 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 30, 2026
12Indirect evidenceHanover, MD, United StatesHQ checked Sep 30, 20261,001-5,0002,866 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 30, 2026
13Partial evidenceLondon, United KingdomHQ checked Sep 30, 20261,001-5,0002,734 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 30, 2026
14Partial evidenceAntwerp, BelgiumHQ checked Sep 30, 20265,001-10,0002,561 contacts →

Partial evidence

“SD Worx is your HR, Pay and Time partner in Europe.”

Source: RevenueBase Database · checked Sep 30, 2026
15Indirect evidenceCesson-sevigne, FranceHQ checked Sep 30, 202610001+2,386 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 30, 2026
16Partial evidenceParis La Défense, GermanyHQ checked Sep 30, 20261,001-5,0002,324 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 30, 2026
17Indirect evidenceMiguel Hidalgo, MexicoHQ checked Sep 30, 20261,001-5,0002,057 contacts →

Indirect evidence

“Un software de recursos humanos para atender todas las necesidades de tus colaboradores.”

Source: RevenueBase Database · checked Sep 30, 2026
18Indirect evidenceLowell, MA, United StatesHQ checked Sep 30, 20265,001-10,0001,889 contacts →

Indirect evidence

“Built from the merger of Ultimate Software & Kronos Inc, we are now UKG.”

Source: RevenueBase Database · checked Sep 30, 2026
19Partial evidenceCourbevoie, FranceHQ checked Sep 30, 20261,001-5,0001,855 contacts →

Partial 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 30, 2026
20Indirect evidenceDraper, UT, United StatesHQ checked Sep 30, 20261,001-5,0001,812 contacts →

Indirect evidence

“For 16 years, BambooHR has embarked on a mission to help organizations and their employees build better workplaces and achieve their unique missions.”

Source: RevenueBase Database · checked Sep 30, 2026
21Partial evidenceMunich, GermanyHQ checked Sep 30, 20261,001-5,0001,786 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 30, 2026
22Indirect evidenceTurin, ItalyHQ checked Sep 30, 2026501-1,0001,748 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 30, 2026
23Partial evidenceMilan, ItalyHQ checked Sep 30, 20265,001-10,0001,717 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 30, 2026
24Indirect evidenceSanto André, BrazilHQ checked Sep 30, 2026n/a1,695 contacts →

Indirect evidence

“Durante os anos 80, o mundo testemunhou o surgimento de uma nova ordem.”

Source: RevenueBase Database · checked Sep 30, 2026
25Indirect evidenceSan Jose, CA, United StatesHQ checked Sep 30, 20261,001-5,0001,669 contacts →

Indirect evidence

“Empowering Technology Services” Founded in 2003, we are in our 22th year of structured growth.”

Source: RevenueBase Database · checked Sep 30, 2026

Showing 25 of 26,120 HR outsourcing service providers worldwide

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HR outsourcing service providers worldwide at a glance

As of Sep 30, 2026
21.8%Verified-email coverage
12.6%Mobile-number coverage
25.1Average contacts per company
1-10Median size (employees)
2.6%Largest-city concentration · Sao Paulo
Sep 30, 2026Page data refreshed

Companies by employee count

1-10
17,418
11-50
5,130
51-200
1,996
201-500
724
501-1,000
331
1,001-5,000
327
5,001-10,000
71
10001+
66

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 service providers, 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
34 countries, largest first: the United States, Brazil, the United Kingdom, France, the Netherlands, Canada, Mexico, Germany, Australia, Argentina and 24 more. Country and city lists for HR outsourcing service providers are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “HR outsourcing service providers”. 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 service providers), 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 service providers, 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, 142,959 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 30, 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 service providers by location

137 lists · largest first

Every HR outsourcing service providers 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 service providers, 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 service providers are there worldwide?

RevenueBase identified 26,120 HR outsourcing service providers 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 Zurich, tops this list with the largest team on record.

Which country has the most HR outsourcing service providers?

The United States leads with 6,598 companies, followed by Brazil (3,111) and the United Kingdom (2,299). Every HR outsourcing service providers list by country and city is linked on this page.

Which city has the most HR outsourcing service providers?

Sao Paulo leads with 683 headquartered companies, followed by London (571) and Paris (358).

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 142,959 verified decision-maker contacts tracked across these 26,120 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 30, 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.