Company lists · Data refreshed September 2026
Top 25 Managed security services companies based in the United Kingdom
RevenueBase identified 1,058 managed security services companies headquartered in the United Kingdom as of September 2026 and tracks 25,048 professional contacts across them, including 7,361 with verified work emails and 2,074 with mobile numbers. London is the largest hub.
This list covers managed security services 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, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 managed security services companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 4,925 | ||||
“Sophos is a cybersecurity leader defending organizations globally with an AI-driven platform and expert-led services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 2 | 852 | ||||
“VSG are one of the UK's leading security solutions providers with a heritage in manned guarding.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 3 | 847 | ||||
“Corps Security - experts in security with social value Built on over 165 years of experience, Corps provides specialist security services, across the UK, to ensure the safety of…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 4 | 502 | ||||
“SecurityHQ, a global cybersecurity company pioneering Security Performance Engineering for stronger operational performance and resilience.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 5 | 419 | ||||
“Ward is an award winning, privately owned business, providing bespoke risk and security solutions including protective security personnel, explosive search dogs, narcotic search…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 6 | 392 | ||||
“SSGC is a leading innovator in the Manned Guarding industry, specialising in the application of new technology to improve the performance of its Management team, deployed staff…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 7 | 297 | ||||
“At Quorum Cyber, we're on a mission to help good people win.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 8 | 242 | ||||
“Obrela Security Industries is a global provider of cyber security services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 9 | 190 | ||||
“Intragen is a cyber security business focused on managed Identity solutions and services.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 10 | 178 | ||||
“24 x 7 Cloud Service Provider & Managed Security Service Provider delivering technology transformation.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 11 | Unitrust Protection ServicesPartial evidence | 175 | |||
“We are able to supply a one stop security service for all types of security requirement.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 12 | 168 | ||||
“Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 13 | 166 | ||||
“We are GUK.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 14 | 162 | ||||
“One of the largest independent security companies in the UK.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 15 | 159 | ||||
“At Cyberfort we are passionate about the cyber security services we deliver for our customers which keeps their people, data, systems and technology infrastructure secure…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 16 | 156 | ||||
“Performanta is a global cybersecurity and data risk management company dedicated to protecting people where data matters most.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 17 | 127 | ||||
“Vespasian Security was formed in February 2006.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 18 | 125 | ||||
“KHIPU Networks is an award winning international Cyber Security Company delivering a wide range of network, wireless and security solutions, technologies and services across…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 19 | 123 | ||||
“Bulletproof is now part of WorkNest Secure.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 20 | 113 | ||||
“Doherty Associates is a Managed Service Provider delivering IT support, cyber security and AI enablement ‘beyond the call’.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 21 | 105 | ||||
“Cybersecurity specialists providing technology and telecoms solutions that gives you the leadership, experience and resilience you need to build and secure the future of work.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 22 | 96 | ||||
“CyberOne is a Microsoft Security Elite Partner and one of only 100 global Microsoft partners recognised with Microsoft-Verified Managed XDR solution status.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 23 | 95 | ||||
“SEP2 is an award-winning UK-based cyber security specialist service provider, powered by a dedicated team of experts available 24/7/365.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 24 | 88 | ||||
“Cobweb Solutions is a leading managed service provider helping SMEs across the UK and Middle East improve productivity, strengthen cyber security, and unlock the value of AI and…” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
| 25 | 87 | ||||
“ITC Secure is an advisory-led cyber security services company.” Source: company website · checked Sep 5, 2026Thanks. The Data Team will review it. | |||||
Showing 25 of 1,058 managed security services companies based in the United Kingdom
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Managed security services companies based in the United Kingdom at a glance
As of Sep 5, 2026Companies by employee count
Verified emails by last verification
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 managed security services companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence 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 SmartSearch, 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 “managed security services companies”. Matching reads each company's description, not its industry code or its name.
- What we exclude
- Companies whose own description does not clearly place them among managed security services 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 an evidence 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, 7,361 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 5, 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.
Managed security services companies by metro
Frequently asked
How many managed security services companies are there based in the United Kingdom?
RevenueBase identified 1,058 managed security services 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?
Sophos, headquartered in Abingdon, tops this list with the largest team on record.
Which city has the most managed security services companies?
London leads with 331 headquartered companies, followed by Manchester (37) and Birmingham (27).
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 7,361 verified decision-maker contacts tracked across these 1,058 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 5, 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 SmartSearch, 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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