Company lists · Data refreshed September 2026
Top 25 Employee relations outsourcing companies based in the United Kingdom
RevenueBase identified 1,639 employee relations outsourcing companies headquartered in the United Kingdom as of September 2026 and tracks 31,771 professional contacts across them, including 7,909 with verified work emails. London is the largest hub.
This list covers employee relations outsourcing companies headquartered in the United Kingdom, 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 28, 2026.
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.
The 25 largest employee relations outsourcing companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 20,824 contacts → | ||||
Indirect evidence “Capita is an outsourcer, helping clients across the public and private sectors run complex business processes more efficiently, creating better consumer experiences.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 2 | 1,075 contacts → | ||||
Partial evidence “Peninsula is the worldwide leader and most trusted provider of employment law, HR and health & safety services, supporting over small businesses in the U.K.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 3 | 400 contacts → | ||||
Indirect evidence “Our award winning HR and health & safety services free you from workforce admin and help keep you on the right side of the law.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 4 | 333 contacts → | ||||
Partial evidence “Ubique Systems is a fast growing multifaceted organization which offers a comprehensive array of outsourcing and consulting services for its customers, including recruitment…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 5 | 311 contacts → | ||||
Partial evidence “GI Outsourcing is a UK-based accountants outsourcing firm.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 6 | 169 contacts → | ||||
Indirect evidence “Welcome to The HR Dept.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 7 | 127 contacts → | ||||
Partial evidence “Avensure provides UK businesses with bespoke outsourced HR, Employment Law, and Health & Safety services, built around the principle that protection is personal.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 8 | 120 contacts → | ||||
Indirect evidence “Talent Solutions combines ManpowerGroup's leading global offerings RPO, TAPFIN-MSP and Right Management to provide end-to-end, data-driven capabilities across the talent lifecycle.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 9 | 103 contacts → | ||||
Indirect evidence “At Talent Works, we’re changing the way RPO & MSP programs are accessed, delivered and deployed - delivering smarter, scalable talent solutions to help you build your future…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 10 | 103 contacts → | ||||
Partial evidence “we redefine business process outsourcing, empowering companies to broaden their horizons.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 11 | 99 contacts → | ||||
Indirect evidence “We’ve got a lot to offer our customers; global reach, local expertise, bags of commitment and a huge degree of flexibility and know-how.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 12 | 91 contacts → | ||||
Indirect evidence “Since 1989, CMP has helped organisations resolve workplace conflict professionally, fairly and effectively.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 13 | 79 contacts → | ||||
Indirect evidence “Hire talent; whoever and wherever in the world they are.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 14 | 74 contacts → | ||||
Indirect evidence “SAMpeople, SAMpeople Recruit and SAMpeople Payroll” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 15 | 70 contacts → | ||||
Strong evidence “Invedus Outsourcing is a remote employees outsourcing company.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 16 | 67 contacts → | ||||
Indirect evidence “PayEscape is one of the UK’s fastest growing outsourced Payroll, HR and Time Management providers.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 17 | 66 contacts → | ||||
Indirect evidence “The Portfolio Group is a specialist recruitment agency dedicated to sourcing exceptional talent across four key divisions: Payroll, Credit Control, Procurement and HR, Benefits &…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 18 | 61 contacts → | ||||
Indirect evidence “Based in Europe, Everett Sky specializes in helping businesses scale their teams for growth through transformative solutions and exceptional customer service.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 19 | 59 contacts → | ||||
Indirect evidence “Darwin Rhodes has an unrivalled heritage and was one of the first recruitment firms to specialize in the Insurance market.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 20 | 58 contacts → | ||||
Partial evidence “Award winning RPO – the UK’s leading outsourced recruitment partner ResourceBank is the UK’s leading RPO (Recruitment Process Outsourcing) business.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 21 | 53 contacts → | ||||
Partial evidence “Hunter Adams is an employee-owned HR consultancy, Interim and recruitment business.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 22 | 51 contacts → | ||||
Indirect evidence “Randstad is the world's largest HR services provider and is driven to become the world's most valued 'working life partner', supporting people all over the world to find their…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 23 | 47 contacts → | ||||
Indirect evidence “Leading providers of specialist support services.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 24 | 45 contacts → | ||||
Indirect evidence “At Project Recruit, getting to know our clients is at the heart of what we do.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 25 | 45 contacts → | ||||
Indirect evidence “Safe Computing, now part of Access Group is a vibrant Leicester-based software & services company.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
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: employee relations outsourcing 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 employee relations outsourcing companies.
- Partial evidence
- Its own public description names part of employee relations outsourcing companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name employee relations outsourcing 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 1,639 employee relations outsourcing companies based in the United Kingdom
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 7,909 reachable decision-makers.
Free signup · no credit card
Employee relations outsourcing companies based in the United Kingdom at a glance
As of Sep 28, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 1,639 companies.
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 employee relations 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.
- What qualifies
- Companies headquartered in the United Kingdom whose own description of what they do matches “employee relations 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 employee relations 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 employee relations outsourcing companies, and records with no verified work email. Companies headquartered outside United Kingdom 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 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, 7,909 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 28, 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.
Employee relations outsourcing companies by metro
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 employee relations 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 employee relations outsourcing companies are there based in the United Kingdom?
RevenueBase identified 1,639 employee relations outsourcing companies headquartered in the United Kingdom 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?
Capita, headquartered in London, tops this list with the largest team on record.
Which city has the most employee relations outsourcing companies?
London leads with 348 headquartered companies, followed by Manchester (46) and Leeds (23).
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 7,909 verified decision-maker contacts tracked across these 1,639 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 28, 2026.
Ready to reach these companies? Verified emails and direct dials for all 1,639 employee relations outsourcing companies based in the United Kingdom. Start with a free account, no credit card.
Download this list →Related lists
Employee relations outsourcing companies by geography
- Employee relations outsourcing companies based in Brisbane, Australia
- Employee relations outsourcing companies based in Melbourne, Australia
- Employee relations outsourcing companies based in Perth, Australia
- Employee relations outsourcing companies based in Sydney, Australia
- Employee relations outsourcing companies based in Belo Horizonte, Brazil
- Employee relations outsourcing companies based in Campinas, Brazil
- Employee relations outsourcing companies based in Curitiba, Brazil
- Employee relations outsourcing companies based in Porto Alegre, Brazil
- Employee relations outsourcing companies based in Rio De Janeiro, Brazil
- Employee relations outsourcing companies based in Sao Paulo, Brazil
- Employee relations outsourcing companies based in Calgary, Canada
- Employee relations outsourcing companies based in Edmonton, Canada
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.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Employee relations outsourcing companies based in Brisbane, Australia
- Employee relations outsourcing companies based in Melbourne, Australia
- Employee relations outsourcing companies based in Perth, Australia
- Employee relations outsourcing companies based in Sydney, Australia
- Employee relations outsourcing companies based in Belo Horizonte, Brazil
- Employee relations outsourcing companies based in Campinas, Brazil