Company lists · Data refreshed September 2026

Top 25 Operational technology security companies based in the United Kingdom

Name: Operational technology security 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 5, 2026 96 companies tracked

RevenueBase identified 96 operational technology security companies headquartered in the United Kingdom as of September 2026 and tracks 2,262 professional contacts across them, including 722 with verified work emails and 447 with mobile numbers. London is the largest hub.

This list covers operational technology 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 5, 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 5, 2026 86% judged on-target in blind review

96Companies

2,262Contacts tracked

722Verified emails

447Mobile numbers

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The 25 largest operational technology security companies based in the United Kingdom

Ranked by team size

Top 25 of 96 operational technology security companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names operational technology 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.
#	Company	Headquarters	Employees	Contacts
1	BridewellPartial evidence	Reading, United KingdomHQ checked Sep 5, 2026	201-500	303
	“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 5, 2026
2	SapphireIndirect evidence	Newcastle Upon Tyne, United KingdomHQ checked Sep 5, 2026	51-200	168
	“Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.” Source: company website · checked Sep 5, 2026
3	CyberfortStrong evidence	Thatcham, United KingdomHQ checked Sep 5, 2026	51-200	159
	“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 5, 2026
4	Reliance CyberIndirect evidence	Waterloo, United KingdomHQ checked Sep 5, 2026	51-200	80
	“At Reliance Cyber, we believe in truly partnering with our customers.” Source: company website · checked Sep 5, 2026
5	CyberowlPartial evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	52
	“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: company website · checked Sep 5, 2026
6	NothreatPartial evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	36
	“The future of IoT/OT security is here.” Source: company website · checked Sep 5, 2026
7	Barrier NetworksIndirect evidence	Glasgow, United KingdomHQ checked Sep 5, 2026	11-50	34
	“We are your strategic cybersecurity partner – going beyond traditional models to deliver agile, expert-led protection tailored to the needs of regulated industries and critical…” Source: company website · checked Sep 5, 2026
8	Device AuthorityPartial evidence	Reading, United KingdomHQ checked Sep 5, 2026	11-50	32
	“Device Authority enables end to end cyber resilience for connected devices through the discovery, visibility and automated security of large IoT/OT deployments.” Source: company website · checked Sep 5, 2026
9	Intrinsic SecurityPartial evidence	Peterborough, United KingdomHQ checked Sep 5, 2026	51-200	32
	“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: company website · checked Sep 5, 2026
10	MAC Solutions UK LTDIndirect evidence	Redditch, United KingdomHQ checked Sep 5, 2026	11-50	31
	“MAC Solutions empowers industrial organisations to secure, connect, and innovate by delivering trusted IT and OT solutions.” Source: company website · checked Sep 5, 2026
11	Converged Communication SolutionsIndirect evidence	Aberdeen, United KingdomHQ checked Sep 5, 2026	11-50	29
	“Secure, Connect, Empower.” Source: company website · checked Sep 5, 2026
12	TekgemStrong evidence	Sedgefield, United KingdomHQ checked Sep 5, 2026	11-50	26
	“Tekgem bridges the gap between Information Technology (IT) and Operational Technology (OT).” Source: company website · checked Sep 5, 2026
13	Sword IacsPartial evidence	Aberdeen, United KingdomHQ checked Sep 5, 2026	11-50	22
	“IACS Consulting are an Aberdeen based Industrial Automation Control System consultancy that specialises exclusively in cyber security for the production and safety critical…” Source: company website · checked Sep 5, 2026
14	Blue Cube Security LTDPartial evidence	East Grinstead, United KingdomHQ checked Sep 5, 2026	11-50	22
	“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: company website · checked Sep 5, 2026
15	Cyber EnergiaPartial evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	20
	“Cyber Energia – Your Comprehensive Cyber Security Solution for a smart & sustainable energy market Cyber Energia is a dynamic managed security service provider offering OT / SCADA…” Source: company website · checked Sep 5, 2026
16	Infosec K2kIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	18
	“Infosec K2K safeguards your organisation’s most valuable assets with tailored cybersecurity solutions.” Source: company website · checked Sep 5, 2026
17	SinevisIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	17
	“We are a leading cybersecurity services organization with more than a decade of proven expertise in consulting, solution implementation and managed services.” Source: company website · checked Sep 5, 2026
18	Datasixth ConsultingIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	15
	“Who We Are DataSixth delivers Cybersecurity Intelligence.” Source: company website · checked Sep 5, 2026
19	Bandgi TechnologiesStrong evidence	Maidenhead, United KingdomHQ checked Sep 5, 2026	11-50	14
	“Operational Technology Expertise (Utilities & Manufacturing Industry) Bandgi Technologies has deep hands-on experience delivering OT solutions for utility and industrial…” Source: company website · checked Sep 5, 2026
20	DeltaflareIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	12
	“deltaflare helps critical infrastructure operators modernise securely.” Source: company website · checked Sep 5, 2026
21	Bells IT SupportPartial evidence	Dartford, United KingdomHQ checked Sep 5, 2026	1-10	11
	“Welcome to Bells IT Support, your trusted partner for cyber security and IT support solutions.” Source: company website · checked Sep 5, 2026
22	OtifydStrong evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	11
	“We are a next-gen Operational Technology (OT) cybersecurity leader focused on safeguarding industrial environments so that we can fulfil our purpose: Provide best-in-class OT…” Source: company website · checked Sep 5, 2026
23	CyberprismStrong evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	11
	“CyberPrism safeguards your business-critical Operational Technology (OT).” Source: company website · checked Sep 5, 2026
24	Swidch LTDPartial evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	10
	“swIDch stops OT attacks at the access layer by securing the most vulnerable endpoints in critical infrastructure.” Source: company website · checked Sep 5, 2026
25	Baserock IT SolutionsIndirect evidence	Stokenchurch, United KingdomHQ checked Sep 5, 2026	11-50	9
	“Enabling digital transformation with cyber secure IT/OT convergence.” Source: company website · checked Sep 5, 2026

Showing 25 of 96 operational technology security companies based in the United Kingdom

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Operational technology security companies based in the United Kingdom at a glance

As of Sep 5, 2026

11-50Median size (employees)

LondonLargest hub · 44 HQs

447Contacts with mobile numbers

Sep 5, 2026Data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

1,001-5,000

Verified emails by last verification

0–30

675

31–60

61–90

90–180

180+

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 operational technology 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 “operational technology 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 operational technology 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, 722 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 5, 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.

Operational technology security companies by metro

Operational technology security companies in London44

Frequently asked

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

RevenueBase identified 96 operational technology 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?

Bridewell, headquartered in Reading, tops this list with the largest team on record.

Which city has the most operational technology security companies?

London leads with 44 headquartered companies, followed by Aberdeen (4) and Bristol (2).

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 722 verified decision-maker contacts tracked across these 96 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 5, 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.