Company lists · Data refreshed September 2026

Top 22 Network security companies based in London, United Kingdom

Name: Network security companies based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 13, 2026 65 companies tracked

RevenueBase identified 65 network security companies headquartered in London, United Kingdom as of September 2026 and tracks 599 professional contacts across them, including 121 with verified work emails and 27 with mobile numbers. Across the United Kingdom, London is the largest hub for this category.

This list covers network security companies headquartered in London, 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 13, 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 13, 2026 86% judged on-target in blind review

65Companies

599Contacts tracked

121Verified emails

27Mobile numbers

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The 22 largest network security companies based in London, United Kingdom

Ranked by team size

Top 22 of 65 network security companies based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 13, 2026. RevenueBase Smart Search rates how each company's information relates to network 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	Titania LTD	Strong evidence	London, United KingdomHQ checked Sep 13, 2026	51-200	88 contacts →
	Strong evidence “Dedicated to securing the networks society depends on.” Source: RevenueBase Database · checked Sep 13, 2026
2	Garrison NOW A Part Of Everfox	Indirect evidence	London, United KingdomHQ checked Sep 13, 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 13, 2026
3	Dnssense	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	51-200	29 contacts →
	Partial evidence “DNSSense, positioned under Noventiq during 2024–2025, completed a 100% local-ownership restructuring in 2025 and evolved into a Turkey-based, R&D-driven DNS security company.” Source: RevenueBase Database · checked Sep 13, 2026
4	Nanjgel Solutions	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	51-200	24 contacts →
	Partial evidence “Nanjgel Solutions is focused on delivering the best IT security for businesses.” Source: RevenueBase Database · checked Sep 13, 2026
5	Cyberrey	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	18 contacts →
	Partial evidence “Your Trusted Distribution & Security Solutions in Building and Securing Your Digital Ecosystem Cyberrey is a leading distributor of comprehensive cybersecurity solutions…” Source: RevenueBase Database · checked Sep 13, 2026
6	CST Limited Computer Security Technology	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	17 contacts →
	Partial evidence “We are a London based specialist supplier of cyber defence solution and information security services.” Source: RevenueBase Database · checked Sep 13, 2026
7	Tranchulas	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	15 contacts →
	Partial evidence “Founded in 2006, Tranchulas is a multinational cyber security company having its offices in London, San Francisco, Budapest and Islamabad.” Source: RevenueBase Database · checked Sep 13, 2026
8	vdc.cloud	Strong evidence	London, United KingdomHQ checked Sep 13, 2026	1-10	12 contacts →
	Strong evidence “Our mission is to provide business customers with effective cloud network security solutions that enhance productivity, eliminate silos, reduce costs, and achieve digital…” Source: RevenueBase Database · checked Sep 13, 2026
9	Disclosure Cybersecurity	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	11 contacts →
	Partial evidence “Disclosure Cybersecurity Ltd is a specialist cyber security company, formed by professionals with extensive experience and wide exposure in the cyber security market.” Source: RevenueBase Database · checked Sep 13, 2026
10	PC Power International LTD	Strong evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	10 contacts →
	Strong evidence “PC POWER INTERNATIONAL LTD is a computer & network security company based in the City, London, United Kingdom.” Source: RevenueBase Database · checked Sep 13, 2026
11	Defenx	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	10 contacts →
	Partial evidence “Defenx is an IT company that has an extensive background in providing businesses with cloud based security solutions and support for their digital infrastructure.” Source: RevenueBase Database · checked Sep 13, 2026
12	Threat Protect	Indirect evidence	London, United KingdomHQ checked Sep 13, 2026	1-10	7 contacts →
	Indirect evidence “Threat Protect is a vendor-agnostic cybersecurity, compliance and AI governance partner based in London, working with organisations across finance, legal, energy, pharma…” Source: RevenueBase Database · checked Sep 13, 2026
13	Ultra Horizon	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	1-10	4 contacts →
	Partial evidence “Ultra Horizon Ltd is a cyber security company comprised of computer scientists who design bespoke security solutions for the maritime and defence sector.” Source: RevenueBase Database · checked Sep 13, 2026
14	Grove Group	Indirect evidence	London, United KingdomHQ checked Sep 13, 2026	51-200	3 contacts →
	Indirect evidence “Grove unlocks business success by defending our customers with the most advanced cybersecurity solutions in the market place today.” Source: RevenueBase Database · checked Sep 13, 2026
15	Threatproof	Indirect evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	2 contacts →
	Indirect evidence “At Threatproof, our mission is to redefine cybersecurity for businesses of all sizes.” Source: RevenueBase Database · checked Sep 13, 2026
16	Sesseto Limited	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	2 contacts →
	Partial evidence “Good security consultants are difficult to find, expensive to employ and hard to keep, but we believe that your business doesn’t have to incur a high cost of delivery in order to…” Source: RevenueBase Database · checked Sep 13, 2026
17	Cansol Consulting	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	2 contacts →
	Partial evidence “Founded in 2017, Cansol is a Cyber Security company with office in London and Dubai.” Source: RevenueBase Database · checked Sep 13, 2026
18	Centilon LTD	Strong evidence	London, United KingdomHQ checked Sep 13, 2026	1-10	2 contacts →
	Strong evidence “Centilon Limited provides leading edge security solutions, consultancy and bespoke training to organisations that have a requirement to secure & manage their network…” Source: RevenueBase Database · checked Sep 13, 2026
19	Essential Security UK LTD	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	1-10	2 contacts →
	Partial evidence “Essential Security is a unique company in that we offer a specialised and confidential service meeting your bespoke technological and communications requirements.” Source: RevenueBase Database · checked Sep 13, 2026
20	Secunity Group	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	1 contacts →
	Partial evidence “Managed Cyber Security Services” Source: RevenueBase Database · checked Sep 13, 2026
21	soc.os	Indirect evidence	London, United KingdomHQ checked Sep 13, 2026	11-50	1 contacts →
	Indirect evidence “SOC.OS has joined the Sophos family!” Source: RevenueBase Database · checked Sep 13, 2026
22	Alion4	Partial evidence	London, United KingdomHQ checked Sep 13, 2026	1-10	1 contacts →
	Partial evidence “Alion4 is a leading provider of holistic enterprise-level IT security solutions.” Source: RevenueBase Database · checked Sep 13, 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: network 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 network security companies.
Partial evidence: Its own public description names part of network security companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name network 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 22 of 65 network security companies based in London, United Kingdom

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Network security companies based in London, United Kingdom at a glance

As of Sep 13, 2026

20.2%Verified-email coverage

4.5%Mobile-number coverage

9.2Average contacts per company

11-50Median size (employees)

Sep 13, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

Freshness & accuracy

How recently the business emails were verified and the company information checked

Email last verified

Median 16.0d

850–30

3331–60

061–90

190–180

2180+

Company record updated

Median 78.0d

00–30

19931–60

27661–90

9890–180

26180+

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 network 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 London, United Kingdom whose own description of what they do matches “network 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 network 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 network security companies, and records with no verified work email. Companies headquartered outside London 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, 121 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 13, 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.

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 network 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 network security companies are there based in London, United Kingdom?

RevenueBase identified 65 network security companies headquartered in London, 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?

Titania LTD, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most network security companies?

London leads the United Kingdom with 208 headquartered companies, followed by Manchester (23) 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 121 verified decision-maker contacts tracked across these 65 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 13, 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.