Company lists · Data refreshed September 2026

Top 24 Data center security system installers based in London, United Kingdom

Name: Data center security system installers based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 156 companies tracked

RevenueBase identified 156 data center security system installers headquartered in London, United Kingdom as of September 2026 and tracks 1,157 professional contacts across them, including 345 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers data center security system installers 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 28, 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 28, 2026 86% judged on-target in blind review

156Companies

1,157Contacts tracked

345Verified emails

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The 24 largest data center security system installers based in London, United Kingdom

Ranked by team size

Top 24 of 156 data center security system installers based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to data center security system installers: 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	The Keyholding Company	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	137 contacts →
	Partial evidence “The Keyholding Company are a tech-enabled mobile security services company, specialising in alarm response, mobile patrols, locks and unlocks, emergency and temporary guarding…” Source: RevenueBase Database · checked Sep 28, 2026
2	Custom Intelligent Security	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	51 contacts →
	Partial evidence “Established in Custom Intelligent Security is a technology driven ISO27001 & NSi Gold Accredited independent electronic security specialist with a proven track record of…” Source: RevenueBase Database · checked Sep 28, 2026
3	Sensetech Systems LTD	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	50 contacts →
	Strong evidence “Sensetech Systems Ltd is an LPS1014 Accredited independent Fire Alarm, Security and Structured Data Cabling Company.” Source: RevenueBase Database · checked Sep 28, 2026
4	Electranet UK Limited	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	49 contacts →
	Indirect evidence “Electranet’s mission is to be a preferred partner to the public and private sectors, bringing competitively priced, secure and innovative solutions to the market.” Source: RevenueBase Database · checked Sep 28, 2026
5	Ak9 Security And FM Solutions LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	501-1,000	43 contacts →
	Partial evidence “AK9 Security and FM Solutions offers comprehensive security solutions for businesses, governmental organizations, and residential areas.” Source: RevenueBase Database · checked Sep 28, 2026
6	Gratte Brothers Security Systems & Software	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	39 contacts →
	Partial evidence “Gratte Brothers is an experienced provider of integrated security solutions, which are Built on Strong Values and ultimately deliver a measurable return on investment.” Source: RevenueBase Database · checked Sep 28, 2026
7	Universal Security Systems LTD	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	39 contacts →
	Strong evidence “Universal Security Systems Limited is a specialist provider of installation and maintenance services for all types of security systems including Access Control, Closed Circuit…” Source: RevenueBase Database · checked Sep 28, 2026
8	Pafi LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	32 contacts →
	Partial evidence “Pafi Ltd, Was formed in 1995 to design, install and maintain integrated security solutions for the commercial market.” Source: RevenueBase Database · checked Sep 28, 2026
9	DS Security Group LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	27 contacts →
	Partial evidence “CCTV and Access Control Service and installation specialists Established in 1993 DS Security prides itself on customer service.” Source: RevenueBase Database · checked Sep 28, 2026
10	Welcome Gate	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	23 contacts →
	Strong evidence “Who are you… Most likely you are a Workplace or IT Professional with a lot on your plate including physical electronic security systems, such as - Access control - CCTV - Intruder…” Source: RevenueBase Database · checked Sep 28, 2026
11	Dennis Johns Service Group	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	20 contacts →
	Indirect evidence “The Dennis Johns Service Group is a forward thinking group of companies providing, Electrical, CCTV and Access Control, installation and maintenance contracting services.” Source: RevenueBase Database · checked Sep 28, 2026
12	Integrated Visual Protection Limited	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	16 contacts →
	Partial evidence “Integrated Visual Protection Limited (IVP) is a privately owned Company, which has been established since 2002, providing all types of Fire and Security Services to a variety of…” Source: RevenueBase Database · checked Sep 28, 2026
13	Definitive Security Solutions LTD	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	13 contacts →
	Strong 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 28, 2026
14	OPEM	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	13 contacts →
	Partial evidence “We design, install and maintain CCTV and access control systems across a variety of commercial office sectors including coworking, serviced offices and traditional office design.” Source: RevenueBase Database · checked Sep 28, 2026
15	Square Mile Fire & Security	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	13 contacts →
	Strong evidence “We are an independent business specialising in the delivery of fire systems, as well as a comprehensive range of security systems.” Source: RevenueBase Database · checked Sep 28, 2026
16	Securico Fire & Security	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	12 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
17	The Security Group	Partial evidence	London, United KingdomHQ checked Sep 28, 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 28, 2026
18	Guarding Professionals LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	10 contacts →
	Partial evidence “Guarding Professionals is a customer focused security services company providing cost effective advanced security solutions using technical excellence and superior customer…” Source: RevenueBase Database · checked Sep 28, 2026
19	LDN Security Solutions Limited	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	10 contacts →
	Strong evidence “London-based security company specialising in the design, installation, service and maintenance of single domestic, multi-occupancy residential and commercial security systems.” Source: RevenueBase Database · checked Sep 28, 2026
20	NM Cabling Solutions	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	9 contacts →
	Strong evidence “NM Cabling are a leading data cabling installer assisting IT, Technology, Value Added Re-sellers and Telephone Systems Companies in the London, South and surrounding areas with a…” Source: RevenueBase Database · checked Sep 28, 2026
21	Delta Security 1962 LTD	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	8 contacts →
	Indirect evidence “Our goal is so simple we can sum it up in one word - quality.” Source: RevenueBase Database · checked Sep 28, 2026
22	Pacific Business Solutions LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	8 contacts →
	Partial evidence “We take your security seriously and ensure that you and your property are safe and in secure hands.” Source: RevenueBase Database · checked Sep 28, 2026
23	NES Security Limited	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	7 contacts →
	Strong evidence “An independent electrical services company providing bespoke and high-quality CCTV, Security, Access control and Automation technology systems to private and corporate clients in…” Source: RevenueBase Database · checked Sep 28, 2026
24	Virtus	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	7 contacts →
	Strong 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 28, 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: data center security system installers. 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 data center security system installers.
Partial evidence: Its own public description names part of data center security system installers, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name data center security system installers. 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 24 of 156 data center security system installers based in London, United Kingdom

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Data center security system installers based in London, United Kingdom at a glance

As of Sep 28, 2026

29.8%Verified-email coverage

7.4Average contacts per company

1-10Median size (employees)

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

501-1,000

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 156 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 data center security system installers, 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 “data center security system installers”. 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 data center security system installers), 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 data center security system installers, 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, 345 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 28, 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.

Data center security system installers by metro in the United Kingdom

Data center security system installers in Manchester28

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 data center security system installers, 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 data center security system installers are there based in London, United Kingdom?

RevenueBase identified 156 data center security system installers 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?

The Keyholding Company, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most data center security system installers?

London leads the United Kingdom with 156 headquartered companies, followed by Manchester (28) and Leeds (20).

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 345 verified decision-maker contacts tracked across these 156 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 28, 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.