Company lists · Data refreshed September 2026

Top 25 Outsourcing agencies based in London, United Kingdom

RevenueBase identified 579 outsourcing agencies headquartered in London, United Kingdom as of September 2026 and tracks 28,768 professional contacts across them, including 6,425 with verified work emails. London is the largest hub.

This list covers outsourcing agencies 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 21, 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 21, 2026 86% judged on-target in blind review
579Companies
28,768Contacts tracked
6,425Verified emails
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The 25 largest outsourcing agencies based in London, United Kingdom

Ranked by team size
Top 25 of 579 outsourcing agencies based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to outsourcing agencies: 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 evidenceLondon, United KingdomHQ checked Sep 21, 202610001+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 21, 2026
2Indirect evidenceLondon, United KingdomHQ checked Sep 21, 2026501-1,000746 contacts →

Indirect evidence

“Guidant Global delivers dynamic, tailored workforce solutions that empower businesses to thrive in ever-evolving markets.”

Source: RevenueBase Database · checked Sep 21, 2026
3Strong evidenceLondon, United KingdomHQ checked Sep 21, 2026501-1,000333 contacts →

Strong 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 21, 2026
4Strong evidenceLondon, United KingdomHQ checked Sep 21, 2026201-500311 contacts →

Strong evidence

“GI Outsourcing is a UK-based accountants outsourcing firm.”

Source: RevenueBase Database · checked Sep 21, 2026
5Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-200289 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 21, 2026
6Indirect evidenceLondon, United KingdomHQ checked Sep 21, 2026201-500150 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 21, 2026
7Indirect evidenceLondon, United KingdomHQ checked Sep 21, 2026201-500128 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 21, 2026
8Strong evidenceLondon, United KingdomHQ checked Sep 21, 202651-200115 contacts →

Strong evidence

“At Remoteli, we’re revolutionising staffing, recruitment, and outsourcing.”

Source: RevenueBase Database · checked Sep 21, 2026
9Indirect evidenceLondon, United KingdomHQ checked Sep 21, 2026201-500114 contacts →

Indirect evidence

“Iglu is the global hub for tech talent changing how-and where-businesses do their best work.”

Source: RevenueBase Database · checked Sep 21, 2026
10Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-200100 contacts →

Indirect evidence

“Class1 Personnel is committed to being a class above other recruitment agencies, and our skilled consultants consistently strive to achieve the very best results for our clients.”

Source: RevenueBase Database · checked Sep 21, 2026
11Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202611-5093 contacts →

Indirect evidence

“MRP Group have been providing skilled resources to the communications industry for over 20 years and have subsequently built an extensive network of associates, such that we now…”

Source: RevenueBase Database · checked Sep 21, 2026
12Strong evidenceLondon, United KingdomHQ checked Sep 21, 202651-20090 contacts →

Strong evidence

“A world class offshore outsourcing agency, with offices in London and Harare, we have access to some of the best educated, best spoken graduates you will find anywhere in the…”

Source: RevenueBase Database · checked Sep 21, 2026
13Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-20084 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 21, 2026
14Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-20082 contacts →

Indirect evidence

“Welcome to 9NEXUS- Your Trusted Partner for IT Staff Augmentation & Offshore Solutions.”

Source: RevenueBase Database · checked Sep 21, 2026
15Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202611-5077 contacts →

Indirect evidence

“WESolutions was founded by a team of Healthcare professional who believed that the Healthcare sector needed partners in creating cost effective recruitment solutions for the…”

Source: RevenueBase Database · checked Sep 21, 2026
16Strong evidenceLondon, United KingdomHQ checked Sep 21, 202651-20070 contacts →

Strong evidence

“Invedus Outsourcing is a remote employees outsourcing company.”

Source: RevenueBase Database · checked Sep 21, 2026
17Indirect evidenceLondon, United KingdomHQ checked Sep 21, 20261,001-5,00068 contacts →

Indirect evidence

“Resource Solutions is a leading provider of recruitment and consultancy solutions, managing a recruitment budget of over £2 billion on behalf of our clients since 1997, as part of…”

Source: RevenueBase Database · checked Sep 21, 2026
18Strong evidenceLondon, United KingdomHQ checked Sep 21, 202651-20066 contacts →

Strong evidence

“QORMOTHO is a global outsourcing company.”

Source: RevenueBase Database · checked Sep 21, 2026
19Indirect evidenceLondon, United KingdomHQ checked Sep 21, 2026501-1,00063 contacts →

Indirect evidence

“We are a global company established in 2002, that offers Recruitment, Contract and Compliance Solutions for global Companies.”

Source: RevenueBase Database · checked Sep 21, 2026
20Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202611-5062 contacts →

Indirect evidence

“IDPP has been established for over 37 years, and during that time we have become experts in the IT and Telecoms industries supporting customers with a variety of bespoke services.”

Source: RevenueBase Database · checked Sep 21, 2026
21Strong evidenceLondon, United KingdomHQ checked Sep 21, 202651-20062 contacts →

Strong evidence

“Support Adventure is an outsourcing company that specializes in customer service and support.”

Source: RevenueBase Database · checked Sep 21, 2026
22Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-20053 contacts →

Indirect evidence

“Most UK SMEs hit the same two walls.”

Source: RevenueBase Database · checked Sep 21, 2026
23Strong evidenceLondon, United KingdomHQ checked Sep 21, 202651-20046 contacts →

Strong evidence

“Direct Response can provide outsourcing of voice, data and contact centre services for organisation from a global business to a one-man operation, delivering outstanding service…”

Source: RevenueBase Database · checked Sep 21, 2026
24Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-20041 contacts →

Indirect evidence

“Welcome to Factotum-your secret weapon for streamlined business success!”

Source: RevenueBase Database · checked Sep 21, 2026
25Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202611-5041 contacts →

Indirect evidence

“AnyTask.com is on a mission to transform how digital agencies approach client experiences through its specialized freelance platform.”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 579 outsourcing agencies based in London, United Kingdom

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Outsourcing agencies based in London, United Kingdom at a glance

As of Sep 21, 2026
22.3%Verified-email coverage
49.7Average contacts per company
1-10Median size (employees)
100.0%Largest-city concentration · London
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
302
11-50
172
51-200
72
201-500
17
501-1,000
6
1,001-5,000
3
5,001-10,000
1
10001+
5

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 579 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 outsourcing agencies, 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 “outsourcing agencies”. 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 outsourcing agencies), 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 outsourcing agencies, 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, 6,425 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 21, 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.

Outsourcing agencies 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 outsourcing agencies, 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 outsourcing agencies are there based in London, United Kingdom?

RevenueBase identified 579 outsourcing agencies 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?

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

Which city has the most outsourcing agencies?

London leads with 579 headquartered companies, followed by Manchester (61) and Birmingham (26).

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 6,425 verified decision-maker contacts tracked across these 579 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 21, 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.