Company lists · Data refreshed September 2026

Top 23 Plc security companies based in London, United Kingdom

Name: Plc security companies based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 29, 2026 89 companies tracked

RevenueBase identified 89 plc security companies headquartered in London, United Kingdom as of September 2026 and tracks 772 professional contacts across them, including 277 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers plc security companies headquartered in London, 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 29, 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 29, 2026 86% judged on-target in blind review

89Companies

772Contacts tracked

277Verified emails

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The 23 largest plc security companies based in London, United Kingdom

Ranked by team size

Top 23 of 89 plc security companies based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to plc security 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	Obrela	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	201-500	242 contacts →
	Partial evidence “Obrela Security Industries is a global provider of cyber security services.” Source: RevenueBase Database · checked Sep 29, 2026
2	Black Diamond Security	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	201-500	58 contacts →
	Partial evidence “Black Diamond Security - Safeguarding Your World.” Source: RevenueBase Database · checked Sep 29, 2026
3	Cyber Energia	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	20 contacts →
	Partial evidence “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: RevenueBase Database · checked Sep 29, 2026
4	Definitive Security Solutions LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	13 contacts →
	Partial evidence “Definitive Security Solutions are an established designer, installer and maintainer of security, CCTV, intruder alarms, access control, power and data, and fire detection systems.” Source: RevenueBase Database · checked Sep 29, 2026
5	Deltaflare	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	12 contacts →
	Indirect evidence “deltaflare helps critical infrastructure operators modernise securely.” Source: RevenueBase Database · checked Sep 29, 2026
6	The Security Group	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	11 contacts →
	Partial evidence “The Security Group delivers state-of-the-art security solutions to protect businesses, assets, and people.” Source: RevenueBase Database · checked Sep 29, 2026
7	Otifyd	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	11 contacts →
	Indirect evidence “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: RevenueBase Database · checked Sep 29, 2026
8	Fire Plus Security	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	10 contacts →
	Partial evidence “At Fire Plus Security we are proud to deliver tailored Fire & Security solutions to residential, commercial and public sector organisations throughout the UK & Europe.” Source: RevenueBase Database · checked Sep 29, 2026
9	Cyberseer	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	8 contacts →
	Partial evidence “Cyberseer offers Advanced Threat Detection and a 24×7 Managed Security Service (MSS).” Source: RevenueBase Database · checked Sep 29, 2026
10	Icyberdefence	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	8 contacts →
	Partial evidence “iCyberDefence is a boutique cybersecurity services firm that offers a wide range of security consulting and security engineering services with the necessary products and tools.” Source: RevenueBase Database · checked Sep 29, 2026
11	Virtus	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	7 contacts →
	Partial evidence “Virtus Security are a professional security systems installer with over 20 years of experience within the industry, specialising in the We pride ourselves on the quality of our…” Source: RevenueBase Database · checked Sep 29, 2026
12	Antron Security LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	6 contacts →
	Partial evidence “Antron Security Limited are a respected and reputable security specialist that has been servicing the UK security market since 1988.” Source: RevenueBase Database · checked Sep 29, 2026
13	White Coast Security	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	5 contacts →
	Partial evidence “We Empower Organizations Worldwide with Cutting-Edge Security Solutions.” Source: RevenueBase Database · checked Sep 29, 2026
14	Amovada	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	5 contacts →
	Indirect evidence “Amovada is a leading consultancy specialising in Operational Technology (OT) Cybersecurity for global manufacturing companies.” Source: RevenueBase Database · checked Sep 29, 2026
15	Dram Fire & Security	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	4 contacts →
	Partial evidence “We are one of London’s leading providers of high-quality security and fire detection solutions, DRAM Fire & Security was founded in 2009, and carries a wealth of knowledge and…” Source: RevenueBase Database · checked Sep 29, 2026
16	Ge4orce Fire & Security Solutions	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	4 contacts →
	Indirect evidence “We provide CCTV, alarm systems, access control and fire safety solutions for residential and commercial properties across London.” Source: RevenueBase Database · checked Sep 29, 2026
17	Prime Fire & Security	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	4 contacts →
	Indirect evidence “We provide a comprehensive range of services in Intruder Alarms, Fire Alarms, CCTV, Access Control and much more!” Source: RevenueBase Database · checked Sep 29, 2026
18	Trinity OT Security	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	3 contacts →
	Partial evidence “Trinity OT Security specialises in cybersecurity solutions, system integration and professional services for Operational Technology (OT) environments.” Source: RevenueBase Database · checked Sep 29, 2026
19	G6s Security Limited	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	3 contacts →
	Partial evidence “G6S Security Limited is an Award Winning, Eco-friendly, Digital Security and Fire Installations and Services Company, delivering expertise in CCTV, Access Control, Intruder, Door…” Source: RevenueBase Database · checked Sep 29, 2026
20	Bison Security	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	3 contacts →
	Partial evidence “Bison Security delivers smart, rapid-deployment security systems tailored for construction sites, commercial premises, infrastructure projects, and high-risk environments across…” Source: RevenueBase Database · checked Sep 29, 2026
21	Pbosecure Trading AS Cybersys Technologies Ltd. In UK	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	3 contacts →
	Indirect evidence “PBOSECURE (Trading as CYBERSYS TECHNOLOGIES)** is a UK-based industrial solutions company specialising in Vapor Recovery Units (VRU), emission reduction technologies, and energy…” Source: RevenueBase Database · checked Sep 29, 2026
22	Intelligent Security And Fire Limited	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	2 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 29, 2026
23	Checksec	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	2 contacts →
	Partial evidence “CheckSec is a UK based provider of security services and technologies, with a global focus.” Source: RevenueBase Database · checked Sep 29, 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: plc security 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 plc security companies.
Partial evidence: Its own public description names part of plc security companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name plc security 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 23 of 89 plc security companies based in London, United Kingdom

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Plc security companies based in London, United Kingdom at a glance

As of Sep 29, 2026

35.9%Verified-email coverage

8.7Average contacts per company

11-50Median size (employees)

Sep 29, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 89 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 plc security 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 London, United Kingdom whose own description of what they do matches “plc security 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 plc security 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 plc security companies, and records with no verified work email. Companies headquartered outside London 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, 277 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 29, 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 plc security 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 plc security companies are there based in London, United Kingdom?

RevenueBase identified 89 plc security companies headquartered in London, 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?

Obrela, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most plc security companies?

London leads the United Kingdom with 89 headquartered companies, followed by Birmingham (15) and Manchester (15).

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 277 verified decision-maker contacts tracked across these 89 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 29, 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.