Company lists · Data refreshed September 2026

Top 19 Infrastructure security companies based in the United Kingdom

RevenueBase identified 1,173 infrastructure security companies headquartered in the United Kingdom as of September 2026 and tracks 21,073 professional contacts across them, including 8,215 with verified work emails and 2,421 with mobile numbers. London is the largest hub.

This list covers infrastructure security 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, how directly it supports the match, and when it was last checked. Data refreshed September 3, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 Match evidence on every row Refreshed Sep 3, 2026 86% judged on-target in blind review
1,173Companies
21,073Contacts tracked
8,215Verified emails
2,421Mobile numbers
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The 19 largest infrastructure security companies based in the United Kingdom

Ranked by team size
Top 19 of 1,173 infrastructure security companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 3, 2026. Evidence rates how directly each company's own description names infrastructure security companies: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
SophosIndirect evidence
Abingdon, United KingdomHQ checked Sep 3, 20265,001-10,0004,963

“Sophos is a cybersecurity leader defending organizations globally with an AI-driven platform and expert-led services.”

Source: company website · checked Sep 3, 2026
2
BridewellStrong evidence
Reading, United KingdomHQ checked Sep 3, 2026201-500304

“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: company website · checked Sep 3, 2026
3
Quorum CyberIndirect evidence
Edinburgh, United KingdomHQ checked Sep 3, 2026201-500292

“At Quorum Cyber, we're on a mission to help good people win.”

Source: company website · checked Sep 3, 2026
4
ROC TechnologiesIndirect evidence
United KingdomHQ checked Sep 3, 2026201-500245

“Roc Technologies delivers transformational IT solutions to public and private sector organisations across the UK.”

Source: company website · checked Sep 3, 2026
5Romford, United KingdomHQ checked Sep 3, 2026201-500200

“OpenView Security Solutions is the UK’S largest privately owned independent security company and provides unique, innovative and technologically excellent solutions to meet…”

Source: company website · checked Sep 3, 2026
6
FournetIndirect evidence
Manchester, United KingdomHQ checked Sep 3, 2026201-500173

“FourNet transforms the customer and citizen services people rely on every day.”

Source: company website · checked Sep 3, 2026
7
Exclusive Networks UKPartial evidence
Alton, United KingdomHQ checked Sep 3, 2026201-500168

“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: company website · checked Sep 3, 2026
8
SapphireIndirect evidence
Newcastle Upon Tyne, United KingdomHQ checked Sep 3, 202651-200165

“Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.”

Source: company website · checked Sep 3, 2026
9
CyberfortStrong evidence
Thatcham, United KingdomHQ checked Sep 3, 202651-200160

“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: company website · checked Sep 3, 2026
10
LOGIQStrong evidence
Bradley Stoke, United KingdomHQ checked Sep 3, 2026201-500142

“Logiq is a UK-based cyber security consultancy and secure managed services provider supporting defence, government, and critical national infrastructure (CNI) organisations where…”

Source: company website · checked Sep 3, 2026
11
Khipu NetworksPartial evidence
Fleet, United KingdomHQ checked Sep 3, 202651-200129

“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: company website · checked Sep 3, 2026
12
Bulletproof Cyber SecurityIndirect evidence
London, United KingdomHQ checked Sep 3, 202651-200118

“Bulletproof is now part of WorkNest Secure.”

Source: company website · checked Sep 3, 2026
13
Appcheck LTDPartial evidence
Leeds, United KingdomHQ checked Sep 3, 202651-20097

“AppCheck is a Complete Enterprise Security Testing Solution that provides up to the minute vulnerability coverage for your entire estate.”

Source: company website · checked Sep 3, 2026
14London, United KingdomHQ checked Sep 3, 2026201-50097

“As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.”

Source: company website · checked Sep 3, 2026
15
OptilanPartial evidence
Royal Leamington Spa, United KingdomHQ checked Sep 3, 2026201-50094

“Optilan is a leading independent security and communications systems integrator worldwide.”

Source: company website · checked Sep 3, 2026
16
Titania LTDPartial evidence
London, United KingdomHQ checked Sep 3, 202651-20089

“Dedicated to securing the networks society depends on.”

Source: company website · checked Sep 3, 2026
17
ITC SecurePartial evidence
London, United KingdomHQ checked Sep 3, 202651-20087

“ITC Secure is an advisory-led cyber security services company.”

Source: company website · checked Sep 3, 2026
18
Wavenet CyberguardPartial evidence
Stourport-on-severn, United KingdomHQ checked Sep 3, 2026201-50086

“CyberGuard Technologies is the security division of Wavenet.”

Source: company website · checked Sep 3, 2026
19
Amethyst Risk ManagementIndirect evidence
Basingstoke, United KingdomHQ checked Sep 3, 202611-5084

“Amethyst Risk Management is a leading cybersecurity consultancy supplying expert services and support to the UK Government, Defence, Operators of Essential Services, and the…”

Source: company website · checked Sep 3, 2026

Showing 19 of 1,173 infrastructure security companies based in the United Kingdom

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Infrastructure security companies based in the United Kingdom at a glance

As of Sep 3, 2026
1-10Median size (employees)
LondonLargest hub · 438 HQs
2,421Contacts with mobile numbers
Sep 3, 2026Data refreshed

Companies by employee count

1-10
679
11-50
340
51-200
103
201-500
27
501-1,000
9
1,001-5,000
4
5,001-10,000
2
10001+
1

Verified emails by last verification

0–30
0
31–60
688
61–90
4,766
90–180
2,641
180+
120

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 infrastructure security companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence 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 SmartSearch, 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 “infrastructure security companies”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among infrastructure security 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 an evidence 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, 8,215 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 3, 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.

Infrastructure security companies by metro

  • Infrastructure security companies in London438
  • Infrastructure security companies in Manchester40

Frequently asked

How many infrastructure security companies are there based in the United Kingdom?

RevenueBase identified 1,173 infrastructure security 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 infrastructure security companies?

London leads with 438 headquartered companies, followed by Manchester (40) and Birmingham (23).

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 8,215 verified decision-maker contacts tracked across these 1,173 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 3, 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 SmartSearch, 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.