Company lists · Data refreshed September 2026

Top 25 Payroll outsourcing companies based in the United States

RevenueBase identified 1,062 payroll outsourcing companies headquartered in the United States as of September 2026 and tracks 124,573 professional contacts across them, including 44,482 with verified work emails and 37,256 with mobile numbers. New York is the largest hub.

This list covers payroll outsourcing companies headquartered in the United States, 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, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 Match evidence on every row Refreshed Sep 5, 2026 86% judged on-target in blind review
1,062Companies
124,573Contacts tracked
44,482Verified emails
37,256Mobile numbers
Unlock all 1,062 companies Free signup · no credit card · 500 free credits

The 25 largest payroll outsourcing companies based in the United States

Ranked by team size
Top 25 of 1,062 payroll outsourcing companies based in the United States, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names payroll outsourcing companies: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
ADPIndirect evidence
Roseland, NJ, United StatesHQ checked Sep 5, 202610001+84,166

“Designing better ways to work through cutting-edge products, premium services and exceptional experiences that enable people to reach their full potential.”

Source: company website · checked Sep 5, 2026
2
PaychexPartial evidence
Rochester, NY, United StatesHQ checked Sep 5, 202610001+17,911

“As the future of work continues to evolve, Paychex leads the way by making complex HR, payroll, and benefits brilliantly simple.”

Source: company website · checked Sep 5, 2026
3
TrinetIndirect evidence
Dublin, CA, United StatesHQ checked Sep 5, 20261,001-5,0004,056

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

Source: company website · checked Sep 5, 2026
4
GUSTOIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 20261,001-5,0003,543

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

Source: company website · checked Sep 5, 2026
5
CoadvantageIndirect evidence
Bradenton, FL, United StatesHQ checked Sep 5, 2026201-500586

“CoAdvantage is now CoAd.”

Source: company website · checked Sep 5, 2026
6Richfield, OH, United StatesHQ checked Sep 5, 2026501-1,000535

“We provide comprehensive HR solutions to companies of all sizes throughout the United States.”

Source: company website · checked Sep 5, 2026
7
InfosyncIndirect evidence
Wichita, KS, United StatesHQ checked Sep 5, 2026501-1,000525

“In today's fast-paced business landscape, multi-unit companies demand more than just basic operations-they need expert guidance and cutting-edge technology to thrive.”

Source: company website · checked Sep 5, 2026
8
PrismhrPartial evidence
Chandler, AZ, United StatesHQ checked Sep 5, 2026201-500436

“PrismHR creates exceptional software and services, empowering human resource outsourcing service providers such as Professional Employer Organizations (PEOs) and HR outsourcers to…”

Source: company website · checked Sep 5, 2026
9
FrankcrumPartial evidence
Clearwater, FL, United StatesHQ checked Sep 5, 2026201-500383

“FrankCrum offers outsourced HR, payroll and payroll administration, employee benefits and benefits administration, 401(k), workers compensation and HR Solutions.”

Source: company website · checked Sep 5, 2026
10
BASICIndirect evidence
Monona, WI, United StatesHQ checked Sep 5, 202651-200324

“BASIC's integrated HR solutions come full-circle for employers nationwide.”

Source: company website · checked Sep 5, 2026
11
Experian Employer ServicesIndirect evidence
Costa Mesa, CA, United StatesHQ checked Sep 5, 2026501-1,000291

“Employers need a partner they can rely on to face today’s new challenges.”

Source: company website · checked Sep 5, 2026
12
Questco CompaniesPartial evidence
The Woodlands, TX, United StatesHQ checked Sep 5, 202651-200279

Outsourcing HR through a PEO is a strong option for growing businesses.”

Source: company website · checked Sep 5, 2026
13
SurepayrollPartial evidence
Rochester, NY, United StatesHQ checked Sep 5, 2026201-500276

“From start-up to scale-up, SurePayroll online payroll, tax management, HR and benefits solutions give small business and household employers the freedom to succeed.”

Source: company website · checked Sep 5, 2026
14
INOVAStrong evidence
Nashville, TN, United StatesHQ checked Sep 5, 2026201-500271

“Inova Payroll is a leading employer services company, integrating payroll and human capital management (HCM) technology with personalized support and full-service HR outsourcing.”

Source: company website · checked Sep 5, 2026
15San Diego, CA, United StatesHQ checked Sep 5, 202651-200213

“TEAM Risk Management Strategies is the nation’s leading provider of comprehensive, outsourced payroll and human resources services for fiduciaries and advisors whose clients have…”

Source: company website · checked Sep 5, 2026
16
Dominion PayrollPartial evidence
Richmond, VA, United StatesHQ checked Sep 5, 202651-200197

“Dominion Payroll is a leader in payroll and human resource solutions for clients nationwide.”

Source: company website · checked Sep 5, 2026
17
Heartland PayrollPartial evidence
Rochester, NY, United StatesHQ checked Sep 5, 20261,001-5,000159

“Ovation Payroll is now Heartland Payroll.”

Source: company website · checked Sep 5, 2026
18Mansfield, MA, United StatesHQ checked Sep 5, 2026201-500155

“ConnectPay empowers small businesses across America through hassle-free payroll processing.”

Source: company website · checked Sep 5, 2026
19
Payroll VaultPartial evidence
Littleton, CO, United StatesHQ checked Sep 5, 202611-50149

Payroll Vault has Re-Defined Payroll Payroll Vault is a nationally leading vendor that is re-defining the payroll industry with advanced cloud-based technologies, the highest…”

Source: company website · checked Sep 5, 2026
20
Adams Keegan, INCPartial evidence
Memphis, TN, United StatesHQ checked Sep 5, 202651-200139

“Adams Keegan is a leading national provider of cloud-based, integrated solutions for human resources information systems (HRIS), payroll, employee benefits, and benefits…”

Source: company website · checked Sep 5, 2026
21
opoc.usIndirect evidence
Columbus, OH, United StatesHQ checked Sep 5, 2026201-500135

“OPOC.us (One Point of Care™.”

Source: company website · checked Sep 5, 2026
22Peachtree Corners, GA, United StatesHQ checked Sep 5, 202651-200126

“At Corporate Payroll Services, we relieve you of the burden of processing payroll.”

Source: company website · checked Sep 5, 2026
23
Avitus GroupPartial evidence
Billings, MT, United StatesHQ checked Sep 5, 2026201-500123

“Avitus Group is a worldwide company that simplifies, strengthens and grows businesses by providing administrative support (Payroll, accounting, taxes, HR and much more.) When a…”

Source: company website · checked Sep 5, 2026
24
Uzio Technology INCIndirect evidence
Great Falls, VA, United StatesHQ checked Sep 5, 202651-200116

“UZIO | UZIO.ai Empowering People.”

Source: company website · checked Sep 5, 2026
25
Coastal PayrollIndirect evidence
San Diego, CA, United StatesHQ checked Sep 5, 202651-200113

“HR starts with human.”

Source: company website · checked Sep 5, 2026

Showing 25 of 1,062 payroll outsourcing companies based in the United States

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Payroll outsourcing companies based in the United States at a glance

As of Sep 5, 2026
1-10Median size (employees)
New YorkLargest hub · 20 HQs
37,256Contacts with mobile numbers
Sep 5, 2026Data refreshed

Companies by employee count

1-10
574
11-50
336
51-200
90
201-500
23
501-1,000
11
1,001-5,000
13
5,001-10,000
4
10001+
7

Verified emails by last verification

0–30
41,060
31–60
2,746
61–90
25
90–180
26
180+
625

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 payroll outsourcing companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence 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 SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “payroll outsourcing companies”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among payroll outsourcing companies, and records with no verified work email. Companies headquartered outside United States 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 an evidence 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, 44,482 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 5, 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.

Frequently asked

How many payroll outsourcing companies are there based in the United States?

RevenueBase identified 1,062 payroll outsourcing companies headquartered in the United States 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 city has the most payroll outsourcing companies?

New York leads with 20 headquartered companies, followed by Houston (14) and Rochester (13).

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 44,482 verified decision-maker contacts tracked across these 1,062 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 5, 2026.

Ready to reach these companies? Verified emails and direct dials for all 1,062 payroll outsourcing companies based in the United States. Start with a free account, no credit card.

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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 SmartSearch, 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.