Company lists · Data refreshed September 2026

Top 25 Enterprise security companies based in the United Kingdom

Name: Enterprise security companies based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 592 companies tracked

RevenueBase identified 592 enterprise security companies headquartered in the United Kingdom as of September 2026 and tracks 12,931 professional contacts across them, including 5,284 with verified work emails. London is the largest hub.

This list covers enterprise security 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, 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

592Companies

12,931Contacts tracked

5,284Verified emails

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The 25 largest enterprise security companies based in the United Kingdom

Ranked by team size

Top 25 of 592 enterprise security companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to enterprise security 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	Sophos	Indirect evidence	Abingdon, United KingdomHQ checked Sep 21, 2026	5,001-10,000	4,925 contacts →
	Indirect evidence “Sophos is a cybersecurity leader defending organizations globally with an AI-driven platform and expert-led services.” Source: RevenueBase Database · checked Sep 21, 2026
2	MTI	Partial evidence	Staines-upon-thames, United KingdomHQ checked Sep 21, 2026	201-500	764 contacts →
	Partial evidence “MTI provides award-winning, end-to-end technology solutions and services in cyber security and data centre for over 35 years.” Source: RevenueBase Database · checked Sep 21, 2026
3	Securityhq	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	501-1,000	502 contacts →
	Partial evidence “SecurityHQ, a global cybersecurity company pioneering Security Performance Engineering for stronger operational performance and resilience.” Source: RevenueBase Database · checked Sep 21, 2026
4	Quorum Cyber	Indirect evidence	Edinburgh, United KingdomHQ checked Sep 21, 2026	201-500	297 contacts →
	Indirect evidence “At Quorum Cyber, we're on a mission to help good people win.” Source: RevenueBase Database · checked Sep 21, 2026
5	Obrela	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	201-500	242 contacts →
	Partial evidence “Obrela Security Industries is a global provider of cyber security services.” Source: RevenueBase Database · checked Sep 21, 2026
6	Cyberfort	Partial evidence	Thatcham, United KingdomHQ checked Sep 21, 2026	51-200	159 contacts →
	Partial evidence “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: RevenueBase Database · checked Sep 21, 2026
7	Performanta	Indirect evidence	Maidenhead, United KingdomHQ checked Sep 21, 2026	51-200	156 contacts →
	Indirect evidence “Performanta is a global cybersecurity and data risk management company dedicated to protecting people where data matters most.” Source: RevenueBase Database · checked Sep 21, 2026
8	Khipu Networks	Partial evidence	Fleet, United KingdomHQ checked Sep 21, 2026	51-200	125 contacts →
	Partial evidence “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: RevenueBase Database · checked Sep 21, 2026
9	Bulletproof Cyber Security	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	123 contacts →
	Indirect evidence “Bulletproof is now part of WorkNest Secure.” Source: RevenueBase Database · checked Sep 21, 2026
10	Total Security Protection LTD	Strong evidence	Watford, United KingdomHQ checked Sep 21, 2026	51-200	116 contacts →
	Strong evidence “TSP has a reputation for providing enterprise security solutions, as well as excellent system integration standards and exceptional aftercare support, since its founding in 1988.” Source: RevenueBase Database · checked Sep 21, 2026
11	Conosco	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	105 contacts →
	Indirect evidence “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: RevenueBase Database · checked Sep 21, 2026
12	Caretower An Integrity360 Company	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	201-500	97 contacts →
	Partial evidence “As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.” Source: RevenueBase Database · checked Sep 21, 2026
13	Sep2	Partial evidence	Leeds, United KingdomHQ checked Sep 21, 2026	51-200	95 contacts →
	Partial evidence “SEP2 is an award-winning UK-based cyber security specialist service provider, powered by a dedicated team of experts available 24/7/365.” Source: RevenueBase Database · checked Sep 21, 2026
14	ITC Secure	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	87 contacts →
	Partial evidence “ITC Secure is an advisory-led cyber security services company.” Source: RevenueBase Database · checked Sep 21, 2026
15	Foregenix	Partial evidence	Swindon, United KingdomHQ checked Sep 21, 2026	51-200	80 contacts →
	Partial evidence “When your business relies on security, compliance and a strong reputation for taking care of your customers, you need a partner that understands your ethos, your challenges and…” Source: RevenueBase Database · checked Sep 21, 2026
16	Telesoft	Indirect evidence	Blandford, United KingdomHQ checked Sep 21, 2026	51-200	68 contacts →
	Indirect evidence “The organisations that run our world face relentless complexity and evolving threats.” Source: RevenueBase Database · checked Sep 21, 2026
17	Eset UK	Indirect evidence	Bournemouth, United KingdomHQ checked Sep 21, 2026	51-200	66 contacts →
	Indirect evidence “We help businesses and individuals stay protected in an increasingly complex digital world.” Source: RevenueBase Database · checked Sep 21, 2026
18	Talk Straight Group	Partial evidence	Ilkley, United KingdomHQ checked Sep 21, 2026	11-50	62 contacts →
	Partial evidence “Talk Straight has been looking after the communications and network security for thousands of public and private sector organisations since 2007.” Source: RevenueBase Database · checked Sep 21, 2026
19	MDSEC	Partial evidence	Macclesfield, United KingdomHQ checked Sep 21, 2026	11-50	61 contacts →
	Partial evidence “MDSec are a UK based consultancy with a passion for information security.” Source: RevenueBase Database · checked Sep 21, 2026
20	Garrison NOW A Part Of Everfox	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	60 contacts →
	Indirect evidence “Garrison is a London-based cybersecurity company founded in 2014 by David Garfield (CEO) and Henry Harrison (Chief Scientist).” Source: RevenueBase Database · checked Sep 21, 2026
21	Cyberlab	Strong evidence	Alderley Edge, United KingdomHQ checked Sep 21, 2026	51-200	57 contacts →
	Strong evidence “CyberLab is the UK-leading cyber security consultancy and managed services provider, trusted by over 1,200 enterprise businesses, government departments, and household names to…” Source: RevenueBase Database · checked Sep 21, 2026
22	Specialist Network Operations	Partial evidence	Oswestry, United KingdomHQ checked Sep 21, 2026	51-200	54 contacts →
	Partial evidence “SNO is a specialist network operations and security partner, helping organisations design, secure, and manage the networks they rely on every day.” Source: RevenueBase Database · checked Sep 21, 2026
23	Hexegic	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	52 contacts →
	Indirect evidence “At Hexegic we are not just passionate about protecting data through our Cyber services we are passionate about helping companies release the potential of the data they hold…” Source: RevenueBase Database · checked Sep 21, 2026
24	Adarma Security	Indirect evidence	Edinburgh, United KingdomHQ checked Sep 21, 2026	201-500	51 contacts →
	Indirect evidence “We are Adarma, independent leaders in detection and response services.” Source: RevenueBase Database · checked Sep 21, 2026
25	Satisnet, A Gamma Company	Partial evidence	Luton, United KingdomHQ checked Sep 21, 2026	51-200	45 contacts →
	Partial evidence “Established in 2004 (acquired by Gamma in 2023), Satisnet, a Gamma company is a pedigree-proven cyber security services and solutions specialist with a fully UK-based 24x7x365 SOC.” Source: RevenueBase Database · checked Sep 21, 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: enterprise security 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 enterprise security companies.
Partial evidence: Its own public description names part of enterprise security companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name enterprise security 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 592 enterprise security companies based in the United Kingdom

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Enterprise security companies based in the United Kingdom at a glance

As of Sep 21, 2026

40.9%Verified-email coverage

21.8Average contacts per company

1-10Median size (employees)

32.6%Largest-city concentration · London

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

326

11-50

179

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

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 592 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 enterprise security 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 the United Kingdom whose own description of what they do matches “enterprise security 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 enterprise security 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 enterprise security 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 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, 5,284 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.

Enterprise security companies by metro

Enterprise security companies in London193

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 enterprise security 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 enterprise security companies are there based in the United Kingdom?

RevenueBase identified 592 enterprise security 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 enterprise security companies?

London leads with 193 headquartered companies, followed by Manchester (19) and Birmingham (12).

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 5,284 verified decision-maker contacts tracked across these 592 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.