Company lists · Data refreshed September 2026

Top 25 Cybersecurity companies based in the United Kingdom

Name: Cybersecurity 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 14, 2026 2,121 companies tracked

Our directory lists 2,121 cybersecurity companies based in the United Kingdom, with 40,035 professional contacts and 15,494 email addresses. The list was last updated in September 2026, and London is the single most-represented city among the companies listed.

Cybersecurity companies provide products and services that protect systems, networks, applications, devices, and data from unauthorized access, disruption, or misuse. This list covers companies that provide cybersecurity products, services, consulting, assessments, monitoring, incident response, or related protection for digital systems and data. Ranked by team size, largest first. Data current as of September 14, 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 14, 2026 86% judged on-target in blind review

2,121Companies

40,035Contacts tracked

15,494Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest cybersecurity companies based in the United Kingdom

Ranked by team size

Top 25 of 2,121 cybersecurity companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 14, 2026. RevenueBase Smart Search rates how each company's information relates to cybersecurity 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	Strong evidence	Abingdon, United KingdomHQ checked Sep 14, 2026	5,001-10,000	4,925 contacts →
	Strong evidence “Sophos is a cybersecurity leader defending organizations globally with an AI-driven platform and expert-led services.” Source: RevenueBase Database · checked Sep 14, 2026
2	Darktrace	Strong evidence	Cambridge, United KingdomHQ checked Sep 14, 2026	1,001-5,000	2,355 contacts →
	Strong evidence “Darktrace is a global leader in AI cybersecurity, providing the essential cybersecurity platform to secure organizations today and for an ever-changing future.” Source: RevenueBase Database · checked Sep 14, 2026
3	Mimecast	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	1,001-5,000	2,304 contacts →
	Indirect evidence “organizations.” Source: RevenueBase Database · checked Sep 14, 2026
4	Hack The BOX	Strong evidence	Folkestone, United KingdomHQ checked Sep 14, 2026	n/a	1,975 contacts →
	Strong evidence “Hack The Box is the leading AI-powered cybersecurity readiness and upskilling platform, trusted by 1,500+ organizations worldwide, including Fortune 500 enterprises, government…” Source: RevenueBase Database · checked Sep 14, 2026
5	MTI	Indirect evidence	Staines-upon-thames, United KingdomHQ checked Sep 14, 2026	201-500	764 contacts →
	Indirect 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 14, 2026
6	ROKE	Indirect evidence	Romsey, United KingdomHQ checked Sep 14, 2026	1,001-5,000	679 contacts →
	Indirect evidence “At Roke, we stand at the forefront of defence and security, delivering cutting-edge intelligence and engineering solutions that protect nations, troops, borders, and businesses.” Source: RevenueBase Database · checked Sep 14, 2026
7	MASS	Indirect evidence	St Neots, United KingdomHQ checked Sep 14, 2026	201-500	640 contacts →
	Indirect evidence “MASS, part of the Cohort plc group, helps you realise the value of your data.” Source: RevenueBase Database · checked Sep 14, 2026
8	Securityhq	Strong evidence	London, United KingdomHQ checked Sep 14, 2026	501-1,000	502 contacts →
	Strong evidence “SecurityHQ, a global cybersecurity company pioneering Security Performance Engineering for stronger operational performance and resilience.” Source: RevenueBase Database · checked Sep 14, 2026
9	S-Rm	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	201-500	351 contacts →
	Indirect evidence “S-RM is a global intelligence and cyber security consultancy.” Source: RevenueBase Database · checked Sep 14, 2026
10	Bridewell	Indirect evidence	Reading, United KingdomHQ checked Sep 14, 2026	201-500	303 contacts →
	Indirect evidence “Bridewell is the trusted cyber security partner for organisations operating within Critical National Infrastructure (CNI), as well as companies who want the highest standard of…” Source: RevenueBase Database · checked Sep 14, 2026
11	Quorum Cyber	Indirect evidence	Edinburgh, United KingdomHQ checked Sep 14, 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 14, 2026
12	Kape Technologies	Strong evidence	London, United KingdomHQ checked Sep 14, 2026	201-500	296 contacts →
	Strong evidence “Kape is a cybersecurity company focused on helping everyone have a better digital experience with greater privacy and protection.” Source: RevenueBase Database · checked Sep 14, 2026
13	Xalient	Indirect evidence	Leeds, United KingdomHQ checked Sep 14, 2026	201-500	260 contacts →
	Indirect evidence “We are a global boutique, specializing exclusively in the convergence of identity-driven security and networking.” Source: RevenueBase Database · checked Sep 14, 2026
14	Obrela	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	201-500	242 contacts →
	Indirect evidence “Obrela Security Industries is a global provider of cyber security services.” Source: RevenueBase Database · checked Sep 14, 2026
15	Netcraft	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	201-500	211 contacts →
	Indirect evidence “Netcraft provides powerful phishing detection, cybercrime disruption and website takedown solutions to the world's largest organizations” Source: RevenueBase Database · checked Sep 14, 2026
16	Intragen	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	201-500	190 contacts →
	Indirect evidence “Intragen is a cyber security business focused on managed Identity solutions and services.” Source: RevenueBase Database · checked Sep 14, 2026
17	Gorilla Technology Group	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	51-200	187 contacts →
	Indirect evidence “Headquartered in London U.K, Gorilla is a global solution provider in Security Intelligence, Network Intelligence, Business Intelligence and IoT technology.” Source: RevenueBase Database · checked Sep 14, 2026
18	Deepcytes Cyber Labs UK	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	51-200	177 contacts →
	Indirect evidence “Whether you’re a business or an individual, digital threats to your precious data and assets can come in any form - external or internal.” Source: RevenueBase Database · checked Sep 14, 2026
19	Security Blue Team	Indirect evidence	London, United KingdomHQ checked Sep 14, 2026	n/a	171 contacts →
	Indirect evidence “Security Blue Team is now Centri.” Source: RevenueBase Database · checked Sep 14, 2026
20	Texecom LTD	Indirect evidence	Haslingden, United KingdomHQ checked Sep 14, 2026	201-500	170 contacts →
	Indirect evidence “Looking after the things people care about, wherever they are’.” Source: RevenueBase Database · checked Sep 14, 2026
21	Sapphire	Indirect evidence	Newcastle Upon Tyne, United KingdomHQ checked Sep 14, 2026	51-200	168 contacts →
	Indirect evidence “Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.” Source: RevenueBase Database · checked Sep 14, 2026
22	Exclusive Networks UK	Strong evidence	Alton, United KingdomHQ checked Sep 14, 2026	201-500	165 contacts →
	Strong evidence “Exclusive Networks is a global trusted cybersecurity specialist for digital infrastructure helping to drive the transition to a totally trusted digital future for all people and…” Source: RevenueBase Database · checked Sep 14, 2026
23	Cyberfort	Indirect evidence	Thatcham, United KingdomHQ checked Sep 14, 2026	51-200	159 contacts →
	Indirect 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 14, 2026
24	Performanta	Strong evidence	Maidenhead, United KingdomHQ checked Sep 14, 2026	51-200	156 contacts →
	Strong evidence “Performanta is a global cybersecurity and data risk management company dedicated to protecting people where data matters most.” Source: RevenueBase Database · checked Sep 14, 2026
25	LOGIQ	Indirect evidence	Bradley Stoke, United KingdomHQ checked Sep 14, 2026	201-500	143 contacts →
	Indirect evidence “Logiq is a UK-based cyber security consultancy and secure managed services provider supporting defence, government, and critical national infrastructure (CNI) organisations where…” Source: RevenueBase Database · checked Sep 14, 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: cybersecurity 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 cybersecurity companies.
Partial evidence: Its own public description names part of cybersecurity companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name cybersecurity 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 2,121 cybersecurity companies based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 15,494 reachable decision-makers.

Free signup · no credit card

View the full list →

Cybersecurity companies based in the United Kingdom at a glance

As of Sep 14, 2026

38.7%Verified-email coverage

18.9Average contacts per company

1-10Median size (employees)

41.1%Largest-city concentration · London

Sep 14, 2026Page data refreshed

Companies by employee count

1-10

1,264

11-50

611

51-200

170

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 2,121 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 cybersecurity 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 “cybersecurity 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 cybersecurity 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 cybersecurity 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, 15,494 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 14, 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.

Cybersecurity companies by metro

Frequently asked

How many cybersecurity companies are in the directory?

The directory lists 2,121 cybersecurity companies based in the United Kingdom.

Which city has the most cybersecurity companies?

London is the single most-represented city among the cybersecurity companies on the list.

How many contacts are available for cybersecurity companies?

The directory includes 40,035 professional contacts and 15,494 email addresses for the listed cybersecurity companies.

Ready to reach these companies? Verified emails and direct dials for all 2,121 cybersecurity companies based in the United Kingdom. Start with a free account, no credit card.

Download this list →

Related lists

Cybersecurity companies by geography

Browse the directory

Browse: Companies home · All United Kingdom lists · All Cybersecurity companies lists · New lists

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.