Company lists · Data refreshed September 2026

Top 23 Security systems integrators based in London, United Kingdom

Name: Security systems integrators based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 305 companies tracked

RevenueBase identified 305 security systems integrators headquartered in London, United Kingdom as of September 2026 and tracks 2,188 professional contacts across them, including 765 with verified work emails. London is the largest hub.

This list covers security systems integrators 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 21, 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 21, 2026 86% judged on-target in blind review

305Companies

2,188Contacts tracked

765Verified emails

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The 23 largest security systems integrators based in London, United Kingdom

Ranked by team size

Top 23 of 305 security systems integrators based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to security systems integrators: 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	QCIC	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	159 contacts →
	Strong evidence “QCIC is an award-winning global engineering firm specialising in designing, building and running security systems.” Source: RevenueBase Database · checked Sep 21, 2026
2	Crossover	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	82 contacts →
	Strong evidence “Crossover is a leading audiovisual systems integrator – we deliver AV that’s high quality, powerful, simple to use, and reliable.” Source: RevenueBase Database · checked Sep 21, 2026
3	WLS	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	61 contacts →
	Partial evidence “WLS (West London Security) has been providing security and solutions to London's homes and businesses for over 40 years.” Source: RevenueBase Database · checked Sep 21, 2026
4	Custom Intelligent Security	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
5	Sensetech Systems LTD	Strong evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
6	Electranet UK Limited	Indirect evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
7	Ak9 Security And FM Solutions LTD	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
8	SMC Smart Homes	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	41 contacts →
	Partial evidence “SMC are a leading custom electronic system design, installation and aftercare company.” Source: RevenueBase Database · checked Sep 21, 2026
9	Gratte Brothers Security Systems & Software	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
10	Universal Security Systems LTD	Strong evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
11	Link Media Systems	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	37 contacts →
	Strong evidence “We are systems integrators.” Source: RevenueBase Database · checked Sep 21, 2026
12	Videxuk	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	36 contacts →
	Partial evidence “We are the experts in door entry and access control and have been supplying and manufacturing systems for 40 years.” Source: RevenueBase Database · checked Sep 21, 2026
13	Pafi LTD	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
14	Okto Technologies	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	32 contacts →
	Strong evidence “Master Systems Integrator OKTO Technologies is a leader in the design, development & installation of Smart Building Technology for- SuperPrime Residential - Luxury Hospitality -…” Source: RevenueBase Database · checked Sep 21, 2026
15	Torpedo Factory Group	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	27 contacts →
	Strong evidence “AMAZING DIGITAL EXPERIENCES THAT WOW BY DESIGN Torpedo Factory Group is a Master Systems Integrator providing professional services for Intelligent Environments & Smart Buildings…” Source: RevenueBase Database · checked Sep 21, 2026
16	DS Security Group LTD	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
17	Principle Networks	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	24 contacts →
	Partial evidence “Principle Networks works with commercial and regulated organisations to reduce cyber risk and cost by simplifying security and network architecture.” Source: RevenueBase Database · checked Sep 21, 2026
18	Interlinked Group	Partial evidence	London, United KingdomHQ checked Sep 21, 2026	51-200	24 contacts →
	Partial evidence “Specialise in Electrical, AV/IT, Wireless Networks, Smart Buildings, Fire & Security in the construction sector, over the UK & Europe.” Source: RevenueBase Database · checked Sep 21, 2026
19	Welcome Gate	Strong evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
20	Dennis Johns Service Group	Indirect evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
21	SW Security Solutions LTD	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	11-50	17 contacts →
	Strong evidence “SW Security Solutions SA - Integrators of electronic security systems in 18 countries around the world.” Source: RevenueBase Database · checked Sep 21, 2026
22	Integrated Visual Protection Limited	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
23	Alchem Technologies LTD	Strong evidence	London, United KingdomHQ checked Sep 21, 2026	1-10	14 contacts →
	Strong evidence “Alchem is a data and systems integrator providing high-end technical capabilities in the national security, defence, and critical infrastructure sectors.” Source: RevenueBase Database · checked Sep 21, 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: security systems integrators. 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 security systems integrators.
Partial evidence: Its own public description names part of security systems integrators, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name security systems integrators. 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 305 security systems integrators based in London, United Kingdom

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Security systems integrators based in London, United Kingdom at a glance

As of Sep 21, 2026

35.0%Verified-email coverage

7.2Average contacts per company

1-10Median size (employees)

100.0%Largest-city concentration · London

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

179

11-50

51-200

201-500

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 305 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 security systems integrators, 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 “security systems integrators”. 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 security systems integrators), 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 security systems integrators, 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, 765 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 21, 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.

Security systems integrators by metro in the United Kingdom

Security systems integrators in London305
Security systems integrators in Manchester52
Security systems integrators in Birmingham34
Security systems integrators in Glasgow33
Security systems integrators in Nottingham31
Security systems integrators in Bristol29
Security systems integrators in Leeds29

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 security systems integrators, 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 security systems integrators are there based in London, United Kingdom?

RevenueBase identified 305 security systems integrators 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?

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

Which city has the most security systems integrators?

London leads with 305 headquartered companies, followed by Manchester (52) and Birmingham (34).

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 765 verified decision-maker contacts tracked across these 305 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 21, 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.