Company lists · Data refreshed September 2026

Top 25 HR outsourcing companies based in London, United Kingdom

Name: HR outsourcing companies based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 12, 2026 578 companies tracked

RevenueBase identified 578 HR outsourcing companies headquartered in London, United Kingdom as of September 2026 and tracks 14,071 professional contacts across them, including 1,555 with verified work emails and 900 with mobile numbers. Across the United Kingdom, London is the largest hub for this category.

This list covers HR outsourcing companies headquartered in London, 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 12, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 12, 2026 86% judged on-target in blind review

578Companies

14,071Contacts tracked

1,555Verified emails

900Mobile numbers

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The 25 largest HR outsourcing companies based in London, United Kingdom

Ranked by team size

Top 25 of 578 HR outsourcing companies based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 12, 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Robert Walters	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	1,001-5,000	4,423 contacts →
	Indirect evidence “Robert Walters is the world’s most trusted talent solutions business.” Source: RevenueBase Database · checked Sep 12, 2026
2	NGA Human Resources, An Alight Company	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	1,001-5,000	2,734 contacts →
	Partial evidence “At Alight \| NGA Human Resources our mission is to make HR work better.” Source: RevenueBase Database · checked Sep 12, 2026
3	Hirexa Solutions	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	377 contacts →
	Indirect evidence “Hirexa Solutions is a leading group of companies committed to delivering exceptional services to Fortune 500 clients worldwide.” Source: RevenueBase Database · checked Sep 12, 2026
4	Ubique Systems	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	501-1,000	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 12, 2026
5	GI Outsourcing	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	311 contacts →
	Partial evidence “GI Outsourcing is a UK-based accountants outsourcing firm.” Source: RevenueBase Database · checked Sep 12, 2026
6	Huntress	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	289 contacts →
	Indirect evidence “Since our establishment in Huntress has been at the forefront of recruitment across a range of specialist sectors.” Source: RevenueBase Database · checked Sep 12, 2026
7	Potentiam LTD	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	150 contacts →
	Indirect evidence “At Potentiam, we help businesses unlock growth by building nearshore and offshore teams that empower organisations to scale faster, operate smarter and stay ahead of the…” Source: RevenueBase Database · checked Sep 12, 2026
8	Ixceed Solutions	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	137 contacts →
	Indirect evidence “iXceed Solutions is a global, end-to-end Talent Solutions, RPO, EOR, Enterprise Services, and Digital Transformation partner trusted by Fortune 100 and high-growth organizations…” Source: RevenueBase Database · checked Sep 12, 2026
9	Newforce Global Services	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	128 contacts →
	Indirect evidence “Newforce provides global recruitment and workforce staffing solutions that help organizations access skilled talent across multiple markets.” Source: RevenueBase Database · checked Sep 12, 2026
10	Omnipresent	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	124 contacts →
	Indirect evidence “Omnipresent was acquired by Deel in October of 2025.” Source: RevenueBase Database · checked Sep 12, 2026
11	Remoteli	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	115 contacts →
	Partial evidence “At Remoteli, we’re revolutionising staffing, recruitment, and outsourcing.” Source: RevenueBase Database · checked Sep 12, 2026
12	Outsourcery	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	84 contacts →
	Indirect evidence “UK businesses are under pressure- Hiring is slower- Costs are rising- And internal teams are stretched thin.” Source: RevenueBase Database · checked Sep 12, 2026
13	Invedus Outsourcing	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	70 contacts →
	Partial evidence “Invedus Outsourcing is a remote employees outsourcing company.” Source: RevenueBase Database · checked Sep 12, 2026
14	The Portfolio Group	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	66 contacts →
	Partial 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 12, 2026
15	Qormotho	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	66 contacts →
	Partial evidence “QORMOTHO is a global outsourcing company.” Source: RevenueBase Database · checked Sep 12, 2026
16	SCEDE	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	64 contacts →
	Indirect evidence “Scede is a trusted scaling partner for tech companies globally, offering a breadth of talent acquisition, people operations and training services, designed to solve key growth…” Source: RevenueBase Database · checked Sep 12, 2026
17	Oakleaf Partnership	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	57 contacts →
	Partial evidence “Since 2005, Oakleaf Partnership has been successfully placing people into jobs across every HR discipline, in every sector imaginable.” Source: RevenueBase Database · checked Sep 12, 2026
18	Hunter Adams	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	51-200	53 contacts →
	Partial evidence “Hunter Adams is an employee-owned HR consultancy, Interim and recruitment business.” Source: RevenueBase Database · checked Sep 12, 2026
19	Warriorz Technologies	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	51 contacts →
	Indirect evidence “In a highly technical industry of Information Technology, Warriorz Technologies Ltd is paving the way in Human Resource and Software consulting across the globe.” Source: RevenueBase Database · checked Sep 12, 2026
20	Project Recruit	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	11-50	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 12, 2026
21	Teamed	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	11-50	40 contacts →
	Indirect evidence “At Teamed, we simplify the process of building teams - no matter where they are in the world.” Source: RevenueBase Database · checked Sep 12, 2026
22	Aviserv	Indirect evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	40 contacts →
	Indirect evidence “We help multi-national and SME's to help manage their complex staff and human resource needs in some of the most challenging environment such as Airports and Hospitals.” Source: RevenueBase Database · checked Sep 12, 2026
23	Fitzgerald	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	11-50	38 contacts →
	Partial evidence “We’re the full-service HR consultancy that synchronises seamlessly with your business.” Source: RevenueBase Database · checked Sep 12, 2026
24	Work For Impact	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	201-500	36 contacts →
	Partial evidence “Work for Impact helps growing companies build high-performing global teams through staffing, recruitment, and ethical outsourcing.” Source: RevenueBase Database · checked Sep 12, 2026
25	Whitecollars	Partial evidence	London, United KingdomHQ checked Sep 12, 2026	11-50	35 contacts →
	Partial evidence “We are Whitecollars, the global Human Resource consulting and recruitment agency that supports your business growth with affordable, flat-fee recruitment solutions and tailored HR…” Source: RevenueBase Database · checked Sep 12, 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: HR 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 HR outsourcing companies.
Partial evidence: Its own public description names part of HR outsourcing companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name HR 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 578 HR outsourcing companies based in London, United Kingdom

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HR outsourcing companies based in London, United Kingdom at a glance

As of Sep 12, 2026

11.1%Verified-email coverage

6.4%Mobile-number coverage

24.3Average contacts per company

1-10Median size (employees)

Sep 12, 2026Page data refreshed

Companies by employee count

1-10

379

11-50

127

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Freshness & accuracy

How recently the business emails were verified and the company information checked

Email last verified

Median 15.0d

1,2850–30

24331–60

461–90

090–180

23180+

Company record updated

Median 77.0d

00–30

5,01931–60

6,93361–90

1,45390–180

666180+

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.
What qualifies: Companies headquartered in London, United Kingdom 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. Companies headquartered outside London 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, 1,555 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 12, 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 metro in the United Kingdom

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 based in London, United Kingdom?

RevenueBase identified 578 HR outsourcing companies headquartered in London, 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?

Robert Walters, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most HR outsourcing companies?

London leads the United Kingdom with 570 headquartered companies, followed by Manchester (56) and Bristol (40).

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 1,555 verified decision-maker contacts tracked across these 578 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 12, 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.