Company lists · Data refreshed September 2026

Top 25 Cloud infrastructure security firms based in the United Kingdom

Name: Cloud infrastructure security 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 27, 2026 409 companies tracked

RevenueBase identified 409 cloud infrastructure security firms headquartered in the United Kingdom as of September 2026 and tracks 10,667 professional contacts across them, including 4,952 with verified work emails. London is the largest hub.

This list covers cloud infrastructure security 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 27, 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 27, 2026 86% judged on-target in blind review

409Companies

10,667Contacts tracked

4,952Verified emails

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The 25 largest cloud infrastructure security firms based in the United Kingdom

Ranked by team size

Top 25 of 409 cloud infrastructure security firms based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 27, 2026. RevenueBase Smart Search rates how each company's information relates to cloud infrastructure security 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	Sophos	Indirect evidence	Abingdon, United KingdomHQ checked Sep 27, 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 27, 2026
2	Iomart	Partial evidence	Glasgow, United KingdomHQ checked Sep 27, 2026	201-500	414 contacts →
	Partial evidence “Iomart combines cutting-edge cloud technology with deep industry expertise to help organisations transform with confidence.” Source: RevenueBase Database · checked Sep 27, 2026
3	Bridewell	Strong evidence	Reading, United KingdomHQ checked Sep 27, 2026	201-500	303 contacts →
	Strong 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 27, 2026
4	Quorum Cyber	Indirect evidence	Edinburgh, United KingdomHQ checked Sep 27, 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 27, 2026
5	Xalient	Partial evidence	Leeds, United KingdomHQ checked Sep 27, 2026	201-500	260 contacts →
	Partial evidence “We are a global boutique, specializing exclusively in the convergence of identity-driven security and networking.” Source: RevenueBase Database · checked Sep 27, 2026
6	Atech Cloud	Strong evidence	Marlow, United KingdomHQ checked Sep 27, 2026	51-200	178 contacts →
	Strong evidence “24 x 7 Cloud Service Provider & Managed Security Service Provider delivering technology transformation.” Source: RevenueBase Database · checked Sep 27, 2026
7	Cyberfort	Strong evidence	Thatcham, United KingdomHQ checked Sep 27, 2026	51-200	159 contacts →
	Strong 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 27, 2026
8	Performanta	Indirect evidence	Maidenhead, United KingdomHQ checked Sep 27, 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 27, 2026
9	Khipu Networks	Partial evidence	Fleet, United KingdomHQ checked Sep 27, 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 27, 2026
10	Bulletproof Cyber Security	Indirect evidence	London, United KingdomHQ checked Sep 27, 2026	51-200	123 contacts →
	Indirect evidence “Bulletproof is now part of WorkNest Secure.” Source: RevenueBase Database · checked Sep 27, 2026
11	RED Sift	Indirect evidence	London, United KingdomHQ checked Sep 27, 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 27, 2026
12	Virtual IT LTD	Partial evidence	South & West Hampstead, United KingdomHQ checked Sep 27, 2026	51-200	79 contacts →
	Partial evidence “Virtual IT are a leading provider of cyber-secure cloud and managed IT services in the UK, entrusted by over 700 businesses and schools as their end-to-end technology partner.” Source: RevenueBase Database · checked Sep 27, 2026
13	Brightsolid	Strong evidence	Dundee, United KingdomHQ checked Sep 27, 2026	51-200	76 contacts →
	Strong evidence “Brightsolid is expert in all things colocation, cloud and cyber security.” Source: RevenueBase Database · checked Sep 27, 2026
14	CIVO	Partial evidence	London, United KingdomHQ checked Sep 27, 2026	51-200	75 contacts →
	Partial evidence “Civo is the Sovereign Cloud and AI platform that frees you to build without limits.” Source: RevenueBase Database · checked Sep 27, 2026
15	Telesoft	Indirect evidence	Blandford, United KingdomHQ checked Sep 27, 2026	51-200	68 contacts →
	Indirect evidence “The organisations that run our world face relentless complexity and evolving threats.” Source: RevenueBase Database · checked Sep 27, 2026
16	Threatspike	Partial evidence	London, United KingdomHQ checked Sep 27, 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 27, 2026
17	Garrison NOW A Part Of Everfox	Indirect evidence	London, United KingdomHQ checked Sep 27, 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 27, 2026
18	Hexegic	Indirect evidence	London, United KingdomHQ checked Sep 27, 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 27, 2026
19	Coretech Security	Partial evidence	Cheltenham, United KingdomHQ checked Sep 27, 2026	51-200	42 contacts →
	Partial evidence “CoreTech is a specialist cyber security company whose people are motivated by the desire to deliver exceptional capabilities coupled with a real sense of mission.” Source: RevenueBase Database · checked Sep 27, 2026
20	Cybaverse	Partial evidence	Portsmouth, United KingdomHQ checked Sep 27, 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 27, 2026
21	Online Support	Strong evidence	Brentford, United KingdomHQ checked Sep 27, 2026	11-50	39 contacts →
	Strong evidence “For over 20 years, we’ve helped businesses stay productive, secure and resilient through reliable IT support, modern cloud solutions and cyber security services designed for…” Source: RevenueBase Database · checked Sep 27, 2026
22	Secarma LTD	Indirect evidence	Manchester, United KingdomHQ checked Sep 27, 2026	11-50	36 contacts →
	Indirect evidence “Secarma exists to keep the world safe.” Source: RevenueBase Database · checked Sep 27, 2026
23	Cyberis	Partial evidence	Tewkesbury, United KingdomHQ checked Sep 27, 2026	11-50	34 contacts →
	Partial evidence “Cyberis are pioneers in customer-focussed information security.” Source: RevenueBase Database · checked Sep 27, 2026
24	Flow Global Solutions	Partial evidence	Hemel Hempstead, United KingdomHQ checked Sep 27, 2026	11-50	32 contacts →
	Partial evidence “Our expert team provide secure datacentre, network and cloud native solutions as well as industry leading managed services.” Source: RevenueBase Database · checked Sep 27, 2026
25	Intrinsic Security	Strong evidence	Peterborough, United KingdomHQ checked Sep 27, 2026	51-200	32 contacts →
	Strong 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 27, 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: cloud infrastructure security 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 cloud infrastructure security firms.
Partial evidence: Its own public description names part of cloud infrastructure security firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name cloud infrastructure security 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 409 cloud infrastructure security firms based in the United Kingdom

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Cloud infrastructure security firms based in the United Kingdom at a glance

As of Sep 27, 2026

46.4%Verified-email coverage

26.1Average contacts per company

1-10Median size (employees)

45.2%Largest-city concentration · London

Sep 27, 2026Page data refreshed

Companies by employee count

1-10

216

11-50

137

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 409 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 cloud infrastructure security 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 “cloud infrastructure security 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 cloud infrastructure security 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 cloud infrastructure security 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, 4,952 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 27, 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 cloud infrastructure security 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 cloud infrastructure security firms are there based in the United Kingdom?

RevenueBase identified 409 cloud infrastructure security 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?

Sophos, headquartered in Abingdon, tops this list with the largest team on record.

Which city has the most cloud infrastructure security firms?

London leads with 185 headquartered companies, followed by Manchester (14) and Birmingham (8).

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 4,952 verified decision-maker contacts tracked across these 409 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 27, 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.