Company lists · Data refreshed September 2026

Top 25 Critical infrastructure protection companies based in the United Kingdom

Name: Critical infrastructure protection 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 19, 2026 462 companies tracked

RevenueBase identified 462 critical infrastructure protection companies headquartered in the United Kingdom as of September 2026 and tracks 11,199 professional contacts across them, including 3,039 with verified work emails. London is the largest hub.

This list covers critical infrastructure protection 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 19, 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 19, 2026 86% judged on-target in blind review

462Companies

11,199Contacts tracked

3,039Verified emails

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The 25 largest critical infrastructure protection companies based in the United Kingdom

Ranked by team size

Top 25 of 462 critical infrastructure protection companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to critical infrastructure protection 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	Frazer-Nash Consultancy	Indirect evidence	Leatherhead, United KingdomHQ checked Sep 19, 2026	1,001-5,000	1,437 contacts →
	Indirect evidence “With offices in the UK and Australia, Frazer-Nash is a leading systems, engineering and technology company.” Source: RevenueBase Database · checked Sep 19, 2026
2	MTI	Indirect evidence	Staines-upon-thames, United KingdomHQ checked Sep 19, 2026	201-500	764 contacts →
	Indirect evidence “MTI provides award-winning, end-to-end technology solutions and services in cyber security and data centre for over 35 years.” Source: RevenueBase Database · checked Sep 19, 2026
3	Securityhq	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	501-1,000	502 contacts →
	Indirect evidence “SecurityHQ, a global cybersecurity company pioneering Security Performance Engineering for stronger operational performance and resilience.” Source: RevenueBase Database · checked Sep 19, 2026
4	Lodge Security	Partial evidence	Cirencester, United KingdomHQ checked Sep 19, 2026	1,001-5,000	422 contacts →
	Partial evidence “Unlike traditional security providers, we're redefining what protection means in today's world.” Source: RevenueBase Database · checked Sep 19, 2026
5	Bridewell	Strong evidence	Reading, United KingdomHQ checked Sep 19, 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 19, 2026
6	Obrela	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	201-500	242 contacts →
	Indirect evidence “Obrela Security Industries is a global provider of cyber security services.” Source: RevenueBase Database · checked Sep 19, 2026
7	Pilgrims Risk Management Group	Indirect evidence	Woking, United KingdomHQ checked Sep 19, 2026	201-500	205 contacts →
	Indirect evidence “Pilgrims are a global security, risk management and service support company that identifies and manages risks for clients across all sectors, including oil & gas, telecoms…” Source: RevenueBase Database · checked Sep 19, 2026
8	Openview Security Solutions Limited	Indirect evidence	Romford, United KingdomHQ checked Sep 19, 2026	201-500	200 contacts →
	Indirect evidence “OpenView Security Solutions is the UK’S largest privately owned independent security company and provides unique, innovative and technologically excellent solutions to meet…” Source: RevenueBase Database · checked Sep 19, 2026
9	Sapphire	Indirect evidence	Newcastle Upon Tyne, United KingdomHQ checked Sep 19, 2026	51-200	168 contacts →
	Indirect evidence “Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.” Source: RevenueBase Database · checked Sep 19, 2026
10	Cyberfort	Partial evidence	Thatcham, United KingdomHQ checked Sep 19, 2026	51-200	159 contacts →
	Partial 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 19, 2026
11	Trpglobal	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	126 contacts →
	Indirect evidence “We are TRPGLOBAL, your strategic partner in helping you with the complexities of risk management.” Source: RevenueBase Database · checked Sep 19, 2026
12	Total Security Protection LTD	Indirect evidence	Watford, United KingdomHQ checked Sep 19, 2026	51-200	116 contacts →
	Indirect evidence “TSP has a reputation for providing enterprise security solutions, as well as excellent system integration standards and exceptional aftercare support, since its founding in 1988.” Source: RevenueBase Database · checked Sep 19, 2026
13	Solace Global	Indirect evidence	Poole, United KingdomHQ checked Sep 19, 2026	201-500	115 contacts →
	Indirect evidence “Solace Global Risk began in 2010 with a simple belief: when people face risk, they need partners who act quickly and stand by their word.” Source: RevenueBase Database · checked Sep 19, 2026
14	Conosco	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	105 contacts →
	Indirect evidence “Cybersecurity specialists providing technology and telecoms solutions that gives you the leadership, experience and resilience you need to build and secure the future of work.” Source: RevenueBase Database · checked Sep 19, 2026
15	ITC Secure	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	87 contacts →
	Indirect evidence “ITC Secure is an advisory-led cyber security services company.” Source: RevenueBase Database · checked Sep 19, 2026
16	Peregrine Risk Management	Indirect evidence	Plymouth, United KingdomHQ checked Sep 19, 2026	201-500	79 contacts →
	Indirect evidence “Peregrine Risk Management is a leading provider of physical security, risk consultancy, travel risk management, security intelligence, and specialist training services.” Source: RevenueBase Database · checked Sep 19, 2026
17	Esmart Networks	Indirect evidence	Braintree, United KingdomHQ checked Sep 19, 2026	51-200	75 contacts →
	Indirect evidence “Securing your power needs to deliver your electrification plans with certainty.” Source: RevenueBase Database · checked Sep 19, 2026
18	Synoptix	Indirect evidence	Bristol, United KingdomHQ checked Sep 19, 2026	51-200	75 contacts →
	Indirect evidence “Synoptix was formed in 2011 to provide engineering solutions across various technical industries.” Source: RevenueBase Database · checked Sep 19, 2026
19	Daintta	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	60 contacts →
	Indirect evidence “We provide deep expertise with technical and business specialists to help clients secure and protect the UK.” Source: RevenueBase Database · checked Sep 19, 2026
20	Assist Security Group	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	11-50	58 contacts →
	Indirect evidence “Assist Security Group (ASG) helps clients build resilient, comprehensive security strategies that protect their people and assets, business continuity and reputation.” Source: RevenueBase Database · checked Sep 19, 2026
21	Black Diamond Security	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	201-500	58 contacts →
	Indirect evidence “Black Diamond Security - Safeguarding Your World.” Source: RevenueBase Database · checked Sep 19, 2026
22	SQR Group Security Solutions LTD	Strong evidence	Barnet, United KingdomHQ checked Sep 19, 2026	501-1,000	58 contacts →
	Strong evidence “In today’s advanced, interconnected world, protecting the infrastructure that allows society to function is crucial.” Source: RevenueBase Database · checked Sep 19, 2026
23	Cyberlab	Indirect evidence	Alderley Edge, United KingdomHQ checked Sep 19, 2026	51-200	57 contacts →
	Indirect evidence “CyberLab is the UK-leading cyber security consultancy and managed services provider, trusted by over 1,200 enterprise businesses, government departments, and household names to…” Source: RevenueBase Database · checked Sep 19, 2026
24	Cyberowl	Strong evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	52 contacts →
	Strong evidence “CyberOwl helps asset operators in the maritime and critical national infrastructure sectors gain visibility, cyber security and cyber compliance of systems on their distributed…” Source: RevenueBase Database · checked Sep 19, 2026
25	Frankton Group LTD	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	48 contacts →
	Indirect evidence “In today’s complex threat environment, businesses, individuals, and organisations require trusted partners to provide the ultimate assurance that their assets are well protected.” Source: RevenueBase Database · checked Sep 19, 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: critical infrastructure protection 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 critical infrastructure protection companies.
Partial evidence: Its own public description names part of critical infrastructure protection companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name critical infrastructure protection 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 462 critical infrastructure protection companies based in the United Kingdom

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Critical infrastructure protection companies based in the United Kingdom at a glance

As of Sep 19, 2026

27.1%Verified-email coverage

24.2Average contacts per company

1-10Median size (employees)

38.3%Largest-city concentration · London

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

249

11-50

118

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 462 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 critical infrastructure protection 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 “critical infrastructure protection 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 critical infrastructure protection 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 critical infrastructure protection 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, 3,039 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 19, 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.

Critical infrastructure protection companies by metro

Critical infrastructure protection companies in London177

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 critical infrastructure protection 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 critical infrastructure protection companies are there based in the United Kingdom?

RevenueBase identified 462 critical infrastructure protection 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?

Frazer-Nash Consultancy, headquartered in Leatherhead, tops this list with the largest team on record.

Which city has the most critical infrastructure protection companies?

London leads with 177 headquartered companies, followed by Manchester (9) and Cambridge (7).

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 3,039 verified decision-maker contacts tracked across these 462 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 19, 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.