Company lists · Data refreshed September 2026
Top 25 Network security system installers based in London, United Kingdom
RevenueBase identified 130 network security system installers headquartered in London, United Kingdom as of September 2026 and tracks 806 professional contacts across them, including 177 with verified work emails. Across the United Kingdom, London is the largest hub for this category.
This list covers network 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 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.
The 25 largest network security system installers based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 97 contacts → | ||||
Partial evidence “As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 2 | 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 29, 2026Thanks. The Data Team will review it. | |||||
| 3 | 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 29, 2026Thanks. The Data Team will review it. | |||||
| 4 | 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 29, 2026Thanks. The Data Team will review it. | |||||
| 5 | 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 29, 2026Thanks. The Data Team will review it. | |||||
| 6 | 24 contacts → | ||||
Partial evidence “Nanjgel Solutions is focused on delivering the best IT security for businesses.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 7 | 22 contacts → | ||||
Partial evidence “Specialsing in cybersecurity, networks, voice and video, we're on a mission to transform workspaces and deliver exceptional outcomes for our clients.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 8 | 20 contacts → | ||||
Partial evidence “Proxar IT Consulting provides IT services and security solutions for businesses of all sizes.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 9 | 14 contacts → | ||||
Partial evidence “SYLVERSYS is a solutions integration firm with a specialty in providing secure computer and network products/solutions for businesses and organizations in the private and public…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 10 | 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 29, 2026Thanks. The Data Team will review it. | |||||
| 11 | 12 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 12 | 10 contacts → | ||||
Strong evidence “PC POWER INTERNATIONAL LTD is a computer & network security company based in the City, London, United Kingdom.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 13 | 10 contacts → | ||||
Partial evidence “Defenx is an IT company that has an extensive background in providing businesses with cloud based security solutions and support for their digital infrastructure.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 14 | 8 contacts → | ||||
Indirect evidence “Our goal is so simple we can sum it up in one word - quality.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 15 | 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 29, 2026Thanks. The Data Team will review it. | |||||
| 16 | 7 contacts → | ||||
Partial evidence “Security Installation Services Ltd provide a fast and efficient security service across Greater London and North Kent that includes the installation and maintenance of a wide…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 17 | 7 contacts → | ||||
Indirect evidence “Threat Protect is a vendor-agnostic cybersecurity, compliance and AI governance partner based in London, working with organisations across finance, legal, energy, pharma…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 18 | 6 contacts → | ||||
Partial evidence “Ansador Ltd has been privately owned since it was founded in 1982, providing system solutions to corporate and global clients across EMEA.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 19 | 6 contacts → | ||||
Indirect evidence “Since 2010, Bespoke Telecoms have been providing some of the of the finest business and residential properties in the Country with the fastest possible internet services…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 20 | 5 contacts → | ||||
Strong evidence “London based security systems integrator presently engaged on some of the most existing London landmark buildings.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 21 | 5 contacts → | ||||
Indirect evidence “At Rexel Cyber we help businesses fight the constant threat of cyber attack and data breach.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 22 | 4 contacts → | ||||
Strong evidence “is a leading provider of integrated network security and fire detection solutions.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 23 | 4 contacts → | ||||
Partial 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, 2026Thanks. The Data Team will review it. | |||||
| 24 | 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, 2026Thanks. The Data Team will review it. | |||||
| 25 | 3 contacts → | ||||
Indirect evidence “Grove unlocks business success by defending our customers with the most advanced cybersecurity solutions in the market place today.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
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: network 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 network security system installers.
- Partial evidence
- Its own public description names part of network 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 network 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 25 of 130 network security system installers based in London, United Kingdom
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Network security system installers based in London, United Kingdom at a glance
As of Sep 29, 2026Companies by employee count
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 130 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 network 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 “network 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 network 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 network 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, 177 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 network 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 network security system installers are there based in London, United Kingdom?
RevenueBase identified 130 network 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?
Caretower An Integrity360 Company, headquartered in London, tops this list with the largest team on record.
Which city in the United Kingdom has the most network security system installers?
London leads the United Kingdom with 130 headquartered companies, followed by Manchester (18) and Birmingham (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 177 verified decision-maker contacts tracked across these 130 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.
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