Company lists · Data refreshed September 2026

Top 25 Manhattan cybersecurity firms based in the United Kingdom

Name: Manhattan cybersecurity firms 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 148 companies tracked

RevenueBase identified 148 manhattan cybersecurity firms headquartered in the United Kingdom as of September 2026 and tracks 2,912 professional contacts across them, including 825 with verified work emails. London is the largest hub.

This list covers manhattan cybersecurity firms 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

148Companies

2,912Contacts tracked

825Verified emails

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The 25 largest manhattan cybersecurity firms based in the United Kingdom

Ranked by team size

Top 25 of 148 manhattan cybersecurity firms 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 manhattan cybersecurity firms: 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	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
2	Cyberfort	Indirect evidence	Thatcham, United KingdomHQ checked Sep 21, 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 21, 2026
3	Wavenet Cyberguard	Indirect evidence	Stourport-on-severn, United KingdomHQ checked Sep 21, 2026	201-500	86 contacts →
	Indirect evidence “CyberGuard Technologies is the security division of Wavenet.” Source: RevenueBase Database · checked Sep 21, 2026
4	Foregenix	Indirect evidence	Swindon, United KingdomHQ checked Sep 21, 2026	51-200	80 contacts →
	Indirect 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
5	Reliance Cyber	Indirect evidence	Waterloo, United KingdomHQ checked Sep 21, 2026	51-200	80 contacts →
	Indirect evidence “At Reliance Cyber, we believe in truly partnering with our customers.” Source: RevenueBase Database · checked Sep 21, 2026
6	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
7	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
8	Core To Cloud	Partial evidence	Cirencester, United KingdomHQ checked Sep 21, 2026	11-50	39 contacts →
	Partial evidence “We help organisations understand, optimise, and strengthen their cybersecurity.” Source: RevenueBase Database · checked Sep 21, 2026
9	Mitigo Group	Indirect evidence	Cheadle, United KingdomHQ checked Sep 21, 2026	51-200	38 contacts →
	Indirect evidence “Mitigo Group keeps professional services firms safe from cyberattack and operationally resilient.” Source: RevenueBase Database · checked Sep 21, 2026
10	Ergos UK	Indirect evidence	Crawley, United KingdomHQ checked Sep 21, 2026	11-50	35 contacts →
	Indirect evidence “ERGOS is an award-winning IT Managed Service Provider.” Source: RevenueBase Database · checked Sep 21, 2026
11	Intrinsic Security	Partial evidence	Peterborough, United KingdomHQ checked Sep 21, 2026	51-200	32 contacts →
	Partial evidence “Intrinsic Security is a UK-headquartered cybersecurity firm delivering 24/7 threat detection, incident response, and resilience across cloud, hybrid, OT, IoT, and identity…” Source: RevenueBase Database · checked Sep 21, 2026
12	Procheckup PCU	Indirect evidence	Portsmouth, United KingdomHQ checked Sep 21, 2026	11-50	29 contacts →
	Indirect evidence “Imagine a world where cyber threats are simply another challenge that you're fully equipped to handle.” Source: RevenueBase Database · checked Sep 21, 2026
13	Encode	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	25 contacts →
	Indirect evidence “Encode is now part of Obrela Security Industries collectively delivering cutting edge Cyber Security Services, empowering organizations to better protect against cyber threats.” Source: RevenueBase Database · checked Sep 21, 2026
14	Toro Solutions	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	23 contacts →
	Indirect evidence “Toro was founded on creating the UK's first Red Team penetration test - and then attacking hundreds of clients by hacking their systems, influencing / social engineering staff and…” Source: RevenueBase Database · checked Sep 21, 2026
15	Blue Cube Security LTD	Indirect evidence	East Grinstead, United KingdomHQ checked Sep 21, 2026	11-50	22 contacts →
	Indirect evidence “Blue Cube Security is a trusted UK cyber security partner with over 25 years of experience helping organisations stay secure in an increasingly complex digital world.” Source: RevenueBase Database · checked Sep 21, 2026
16	Sinevis	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	17 contacts →
	Partial evidence “We are a leading cybersecurity services organization with more than a decade of proven expertise in consulting, solution implementation and managed services.” Source: RevenueBase Database · checked Sep 21, 2026
17	Datasixth Consulting	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	15 contacts →
	Partial evidence “Who We Are DataSixth delivers Cybersecurity Intelligence.” Source: RevenueBase Database · checked Sep 21, 2026
18	Socguardians LTD	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	13 contacts →
	Partial evidence “Our mission at SOCGuardians is to empower organizations to operate confidently in a digital world by providing cutting-edge cybersecurity services.” Source: RevenueBase Database · checked Sep 21, 2026
19	Cyber Armed Security	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	12 contacts →
	Indirect evidence “At Cyber Armed Security, we protect organisations worldwide from evolving cyber threats through intelligence-driven ethical hacking.” Source: RevenueBase Database · checked Sep 21, 2026
20	Disclosure Cybersecurity	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
21	Koncise	Partial evidence	Borehamwood, United KingdomHQ checked Sep 21, 2026	1-10	9 contacts →
	Partial evidence “Award-winning cybersecurity partner.” Source: RevenueBase Database · checked Sep 21, 2026
22	Equilibrium Security	Indirect evidence	Birmingham, United KingdomHQ checked Sep 21, 2026	11-50	9 contacts →
	Indirect evidence “At Equilibrium Security, we’re a team of certified Cyber Security experts dedicated to keeping your business safe.” Source: RevenueBase Database · checked Sep 21, 2026
23	Defensityone	Partial evidence	Milton Keynes, United KingdomHQ checked Sep 21, 2026	11-50	9 contacts →
	Partial evidence “DefensityOne is a cybersecurity solutions provider specializing in proactive threat detection, risk management, and digital defense services.” Source: RevenueBase Database · checked Sep 21, 2026
24	Hytec Information Security, A Civica Company	Indirect evidence	Teddington, United KingdomHQ checked Sep 21, 2026	11-50	8 contacts →
	Indirect evidence “With over 40 years of information security experience, Hytec, a Civica company, is a trusted partner for organisations looking for expert, specialised cyber security protection.” Source: RevenueBase Database · checked Sep 21, 2026
25	Kelltron Consulting Services	Partial evidence	Aylesbury, United KingdomHQ checked Sep 21, 2026	11-50	7 contacts →
	Partial evidence “Kelltron Consulting Services is a globally recognized cybersecurity consulting firm with a strong presence in the United Kingdom, United States, and India.” 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: manhattan cybersecurity firms. 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 manhattan cybersecurity firms.
Partial evidence: Its own public description names part of manhattan cybersecurity firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name manhattan cybersecurity firms. 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 148 manhattan cybersecurity firms based in the United Kingdom

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Manhattan cybersecurity firms based in the United Kingdom at a glance

As of Sep 21, 2026

28.3%Verified-email coverage

19.7Average contacts per company

1-10Median size (employees)

41.9%Largest-city concentration · London

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

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 148 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 manhattan cybersecurity firms, 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 “manhattan cybersecurity firms”. 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 manhattan cybersecurity firms), 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 manhattan cybersecurity firms, 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, 825 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.

Manhattan cybersecurity firms by metro

Manhattan cybersecurity firms in London62

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 manhattan cybersecurity firms, 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 manhattan cybersecurity firms are there based in the United Kingdom?

RevenueBase identified 148 manhattan cybersecurity firms 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?

Securityhq, headquartered in Gb, tops this list with the largest team on record.

Which city has the most manhattan cybersecurity firms?

London leads with 62 headquartered companies, followed by Manchester (7) and Birmingham (3).

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 825 verified decision-maker contacts tracked across these 148 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.