Company lists · Data refreshed September 2026

Top 25 Cybersecurity AI companies based in the United Kingdom

Name: Cybersecurity AI 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 299 companies tracked

RevenueBase identified 299 cybersecurity AI companies headquartered in the United Kingdom as of September 2026 and tracks 14,030 professional contacts across them, including 7,107 with verified work emails. London is the largest hub.

This list covers cybersecurity AI 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

299Companies

14,030Contacts tracked

7,107Verified emails

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The 25 largest cybersecurity AI companies based in the United Kingdom

Ranked by team size

Top 25 of 299 cybersecurity AI 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 cybersecurity AI 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 21, 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 21, 2026
2	Darktrace	Strong evidence	Cambridge, United KingdomHQ checked Sep 21, 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 21, 2026
3	Mimecast	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	1,001-5,000	2,304 contacts →
	Indirect evidence “organizations.” Source: RevenueBase Database · checked Sep 21, 2026
4	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
5	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
6	Gorilla Technology Group	Indirect evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
7	Deepcytes Cyber Labs UK	Indirect evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
8	RED Sift	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	109 contacts →
	Indirect evidence “Red Sift enables organizations to anticipate, respond to, and recover from cyber attacks while continuing to operate effectively.” Source: RevenueBase Database · checked Sep 21, 2026
9	Marss Group	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	97 contacts →
	Partial evidence “MARSS is a global defence and security technology company specialising in AI-enabled Command and Control (C2/C4I), autonomous mission management, and multi-domain surveillance.” Source: RevenueBase Database · checked Sep 21, 2026
10	Cyberone	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	96 contacts →
	Indirect evidence “CyberOne is a Microsoft Security Elite Partner and one of only 100 global Microsoft partners recognised with Microsoft-Verified Managed XDR solution status.” Source: RevenueBase Database · checked Sep 21, 2026
11	Cybersmart	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	84 contacts →
	Partial evidence “Cybersecurity should be simple.” Source: RevenueBase Database · checked Sep 21, 2026
12	Dionach By Nomios	Indirect evidence	Oxford, United KingdomHQ checked Sep 21, 2026	51-200	73 contacts →
	Indirect evidence “Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.” Source: RevenueBase Database · checked Sep 21, 2026
13	Smartnumbers	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	68 contacts →
	Indirect evidence “We help companies in the fight against fraud.” Source: RevenueBase Database · checked Sep 21, 2026
14	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
15	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
16	Threatspike	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	61 contacts →
	Partial evidence “ThreatSpike is the world's first AI-managed IT and security platform, replacing the legacy MSP model entirely.” Source: RevenueBase Database · checked Sep 21, 2026
17	Senseon	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	54 contacts →
	Indirect evidence “SenseOn deploys alongside all of your existing tools, unifying them into a single investigation plane and augmenting your team with cross-domain correlation, analytics, and…” Source: RevenueBase Database · checked Sep 21, 2026
18	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
19	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
20	Cyberq Group	Partial evidence	Birmingham, United KingdomHQ checked Sep 21, 2026	51-200	42 contacts →
	Partial evidence “CyberQ Group is an award-winning, venture-backed, and globally accredited [ISO27K and CREST] cybersecurity leader dedicated to bridging the "protection gap" for high-stakes…” Source: RevenueBase Database · checked Sep 21, 2026
21	Cybaverse	Partial evidence	Portsmouth, United KingdomHQ checked Sep 21, 2026	51-200	41 contacts →
	Partial evidence “We are on a mission to simplify and scale cyber security by combining AI, automation, expert-led services, in a unified platform: giving every organisation, from MSPs to global…” Source: RevenueBase Database · checked Sep 21, 2026
22	Redhunt Labs	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	36 contacts →
	Strong evidence “RedHunt Labs is a research-driven cybersecurity company delivering Continuous Threat Exposure Management (CTEM), PTaaS, and AI Exposure Security.” Source: RevenueBase Database · checked Sep 21, 2026
23	Nothreat	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	36 contacts →
	Indirect evidence “The future of IoT/OT security is here.” Source: RevenueBase Database · checked Sep 21, 2026
24	defense.com	Indirect evidence	Stevenage, United KingdomHQ checked Sep 21, 2026	51-200	32 contacts →
	Indirect evidence “Defense.com is transforming the way businesses manage cyber security by allowing them to easily identify, prioritise and remediate threats.” Source: RevenueBase Database · checked Sep 21, 2026
25	Device Authority	Indirect evidence	Reading, United KingdomHQ checked Sep 21, 2026	11-50	32 contacts →
	Indirect evidence “Device Authority enables end to end cyber resilience for connected devices through the discovery, visibility and automated security of large IoT/OT deployments.” 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: cybersecurity AI 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 AI companies.
Partial evidence: Its own public description names part of cybersecurity AI companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name cybersecurity AI 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 299 cybersecurity AI companies based in the United Kingdom

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Cybersecurity AI companies based in the United Kingdom at a glance

As of Sep 21, 2026

50.7%Verified-email coverage

46.9Average contacts per company

11-50Median size (employees)

54.5%Largest-city concentration · London

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

145

11-50

107

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

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 299 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 AI 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 AI 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 AI 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 AI 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, 7,107 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.

Cybersecurity AI companies by metro

Cybersecurity AI companies in London163

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 cybersecurity AI 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 cybersecurity AI companies are there based in the United Kingdom?

RevenueBase identified 299 cybersecurity AI 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 cybersecurity AI companies?

London leads with 163 headquartered companies, followed by Manchester (9) and Birmingham (5).

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 7,107 verified decision-maker contacts tracked across these 299 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.