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.
The 25 largest outsourcing agencies based in London, 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 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 746 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, 2026Thanks. The Data Team will review it. | |||||
| 3 | 333 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, 2026Thanks. The Data Team will review it. | |||||
| 4 | 311 contacts → | ||||
Strong evidence “GI Outsourcing is a UK-based accountants outsourcing firm.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 6 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 115 contacts → | ||||
Strong evidence “At Remoteli, we’re revolutionising staffing, recruitment, and outsourcing.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 114 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, 2026Thanks. The Data Team will review it. | |||||
| 10 | 100 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, 2026Thanks. The Data Team will review it. | |||||
| 11 | 93 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, 2026Thanks. The Data Team will review it. | |||||
| 12 | 90 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, 2026Thanks. The Data Team will review it. | |||||
| 13 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 82 contacts → | ||||
Indirect evidence “Welcome to 9NEXUS- Your Trusted Partner for IT Staff Augmentation & Offshore Solutions.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 77 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, 2026Thanks. The Data Team will review it. | |||||
| 16 | 70 contacts → | ||||
Strong evidence “Invedus Outsourcing is a remote employees outsourcing company.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 68 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, 2026Thanks. The Data Team will review it. | |||||
| 18 | 66 contacts → | ||||
Strong evidence “QORMOTHO is a global outsourcing company.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 63 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, 2026Thanks. The Data Team will review it. | |||||
| 20 | 62 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, 2026Thanks. The Data Team will review it. | |||||
| 21 | 62 contacts → | ||||
Strong evidence “Support Adventure is an outsourcing company that specializes in customer service and support.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 53 contacts → | ||||
Indirect evidence “Most UK SMEs hit the same two walls.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 46 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, 2026Thanks. The Data Team will review it. | |||||
| 24 | 41 contacts → | ||||
Indirect evidence “Welcome to Factotum-your secret weapon for streamlined business success!” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 41 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, 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: outsourcing agencies. 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 outsourcing agencies.
- Partial evidence
- Its own public description names part of outsourcing agencies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name outsourcing agencies. 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 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, 2026Companies by employee count
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
- Outsourcing agencies in London579
- Outsourcing agencies in Manchester61
- Outsourcing agencies in Birmingham26
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.
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