Company lists · Data refreshed September 2026
Top 25 Outsource admin services based in the United Kingdom
RevenueBase identified 990 outsource admin services headquartered in the United Kingdom as of September 2026 and tracks 3,058 professional contacts across them, including 831 with verified work emails. London is the largest hub.
This list covers outsource admin services 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 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 outsource admin services based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 311 contacts → | ||||
Partial evidence “GI Outsourcing is a UK-based accountants outsourcing firm.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 220 contacts → | ||||
Partial evidence “We deliver value by taking care of admin and non-core tasks, enabling the productivity of our clients’ stakeholders.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 3 | 103 contacts → | ||||
Partial evidence “we redefine business process outsourcing, empowering companies to broaden their horizons.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 4 | 74 contacts → | ||||
Indirect evidence “Streamline your business with our bespoke support services.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 49 contacts → | ||||
Indirect evidence “Get Ahead is a trusted partner for busy business owners who want high-quality, flexible support without the cost and commitment of hiring full-time staff.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 6 | 47 contacts → | ||||
Indirect evidence “Leading providers of specialist support services.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 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. | |||||
| 8 | 32 contacts → | ||||
Partial evidence “Almost every business can save time and money with smart outsourcing from Go-To - how much depends on you.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 31 contacts → | ||||
Indirect evidence “Virtual PA and Secretarial Support as and when you need it.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 10 | 25 contacts → | ||||
Partial evidence “At Freedom Outsourcing, we specialise in Business Process Outsourcing (BPO) to help businesses save money and grow faster with UK managed outsourcing solutions.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 24 contacts → | ||||
Partial evidence “Oakford Advisors Ltd, a Centralis Group company, is an outsourced business services firm which specialises in providing back-office support to start-up or existing companies…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 12 | 24 contacts → | ||||
Partial evidence “Welcome to Paragon Scotland Limited, where we provide comprehensive white-labelled admin, marketing, and customer support services to help businesses maintain a professional image…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 22 contacts → | ||||
Partial evidence “Top Resource Group is your one-stop ally for all business outsourcing needs.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 19 contacts → | ||||
Indirect evidence “Designated PA provides flexible business support services to small business owners, consultants and professionals.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 19 contacts → | ||||
Partial evidence “AGO Outsourcing is a leading provider of outsourced business services, including inbound and outbound customer service and outbound sales as well as social media engagement…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 16 contacts → | ||||
Indirect evidence “At VIP, we are committed to providing brilliant customer service, always putting our clients first.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 16 contacts → | ||||
Partial evidence “Kimon Services provides high-quality outsourced staff across various industries and disciplines, including customer service, data entry, call centres, marketing and sales support…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 15 contacts → | ||||
Indirect evidence “Here at Backoffice we offer a choice of services designed to meet both the agency and operative’s needs.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 12 contacts → | ||||
Indirect evidence “We bring our extensive industry experience to the hum-drum of finance, HR, operations, marketing and compliance so that you can focus on delivering the fun to your customers.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 20 | 10 contacts → | ||||
Partial evidence “We are Business Garage: providing business outsourcing and consultancy services for SMEs: Business Strategy, Financial Management, Payroll, Bookkeeping, HR Consultancy and more!” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 10 contacts → | ||||
Indirect evidence “At I'm Your PA, we're not just virtual assistants - we're your dedicated partners in business success.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 10 contacts → | ||||
Partial evidence “Helping businesses achieve big results by outsourcing.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 9 contacts → | ||||
Partial evidence “Operating from both the UK and the Philippines, Agility Outsourcing was founded with the mission of supporting small to medium-sized businesses in the UK in navigating the…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 8 contacts → | ||||
Partial evidence “Efficiency Back Office Services (Pty) Ltd started in 2022 and is an outsourcing back-office administration company that specialises in providing skilled and fully managed…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 8 contacts → | ||||
Indirect evidence “The Office Genie is the UK’s only multi-award-winning, five-star phone and business support service to give you a 100% delighted money-back guarantee.” 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: outsource admin services. 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 outsource admin services.
- Partial evidence
- Its own public description names part of outsource admin services, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name outsource admin services. 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 990 outsource admin services based in the United Kingdom
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Outsource admin services based in the United Kingdom at a glance
As of Sep 21, 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 990 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 outsource admin services, 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 “outsource admin services”. 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 outsource admin services), 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 outsource admin services, 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, 831 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.
Outsource admin services by metro
- Outsource admin services in London170
- Outsource admin services in Manchester26
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 outsource admin services, 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 outsource admin services are there based in the United Kingdom?
RevenueBase identified 990 outsource admin services 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?
GI Outsourcing, headquartered in London, tops this list with the largest team on record.
Which city has the most outsource admin services?
London leads with 170 headquartered companies, followed by Manchester (26) and Bristol (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 831 verified decision-maker contacts tracked across these 990 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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