Company lists · Data refreshed September 2026
Top 25 Monitoring companies based in the United Kingdom
RevenueBase identified 135 monitoring companies headquartered in the United Kingdom as of September 2026 and tracks 1,208 professional contacts across them, including 270 with verified work emails. London is the largest hub.
This list covers monitoring 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, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 20, 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 monitoring companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 183 contacts → | ||||
Strong evidence “Allied Universal® Electronic Monitoring is the industry leading technology and service company, offering law enforcement and government agencies the widest variety of cutting-edge…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 2 | 68 contacts → | ||||
Strong evidence “is a security and facilities management business with over 25 years’ experience in monitoring, checking and delivering contractor performance for clients.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 3 | 50 contacts → | ||||
Strong evidence “A global security monitoring brand with sister companies in Holland, Belgium and Australia, we recognise that monitoring is an integral part of your business.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 4 | 47 contacts → | ||||
Strong evidence “We develop monitoring tools that make the Internet a safer place for hundreds of international brands.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 5 | 36 contacts → | ||||
Indirect evidence “Based in Huddersfield, West Yorkshire.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 6 | 29 contacts → | ||||
Strong evidence “Farsight Security Services is a market-leading provider of remote monitoring and ARC services.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 7 | 24 contacts → | ||||
Strong evidence “Nortech supply specialist monitoring technology products and services to utilities, generators and system integrators.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 8 | 21 contacts → | ||||
Strong evidence “Specialist CCTV Monitoring and Alarm Monitoring solutions.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 9 | 18 contacts → | ||||
Strong evidence “For Fire, Alarm & CCTV Installation companies who need reliable monitoring solutions for their clients, Fenix is a completely NEW type of alarm management partnership.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 10 | 16 contacts → | ||||
Indirect evidence “For those who are new to us, here’s Oracle Vision in a nut shell.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 11 | 14 contacts → | ||||
Indirect evidence “Care Protect are dedicated to improving standards of care quality and safety by giving reassurance through greater transparency.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 12 | 14 contacts → | ||||
Strong evidence “Security Services Provider specialising in Remote Monitoring; Installations and Maintenance of CCTV, Fire and Intruder Alarms, Access Controls.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 13 | 13 contacts → | ||||
Indirect evidence “As of June 2021 eSafe became part of the Smoothwall family.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 14 | 12 contacts → | ||||
Strong evidence “Bold Communications develops Gemini, an integrated security and safety monitoring platform to maximise efficiency and interoperability in the control room, utilising legacy as…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 15 | 11 contacts → | ||||
Indirect evidence “Guide Security, based in Darwen, is a well-established security company founded twenty-one years ago by the Walker Family.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 16 | 10 contacts → | ||||
Strong evidence “First County Monitoring (FCM) is one of the leading NSI Gold Accredited alarm monitoring specialists in the UK and Ireland.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 17 | 9 contacts → | ||||
Indirect evidence “Corporate IT Systems (CITSL) helps the organisations society depends on most make trust provable.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 18 | 9 contacts → | ||||
Strong evidence “We are DSOC a CCTV Monitoring and Alarm Receiving Centre based in Doncaster.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 19 | 9 contacts → | ||||
Strong evidence “Hevasure provides 24/7, real-time monitoring of closed circuit water systems, covering a wide range of parameters designed to prevent corrosion and identify issues that, if left…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 20 | 9 contacts → | ||||
Strong evidence “VIS is a monitoring company that brings vision, intelligence and safety to construction sites.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 21 | 8 contacts → | ||||
Indirect evidence “Intelligent Security and Fire are an accredited independent security systems company based in West London with over 20 years experience providing installation, maintenance…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 22 | 8 contacts → | ||||
Strong evidence “Established in 2010, Moniteye is an industry-leading name in structural and environmental monitoring.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 23 | 8 contacts → | ||||
Strong evidence “We're a leading developer of continuous water and gas monitoring technology.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 24 | 7 contacts → | ||||
Indirect evidence “ISUMO leverage industry leading technologies to ensure optimum security, availability and compliance throughout your entire network.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 25 | 7 contacts → | ||||
Indirect evidence “Committed to delivering asset integrity confidence, Sentinel's innovative passive systems enable operators to continuously monitor and manage subsea assets.” Source: RevenueBase Database · checked Sep 20, 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: monitoring 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 monitoring companies.
- Partial evidence
- Its own public description names part of monitoring companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name monitoring 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 25 of 135 monitoring companies based in the United Kingdom
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Monitoring companies based in the United Kingdom at a glance
As of Sep 20, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 135 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 monitoring 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 the United Kingdom whose own description of what they do matches “monitoring 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 monitoring 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 monitoring 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 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, 270 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 20, 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 monitoring 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 monitoring companies are there based in the United Kingdom?
RevenueBase identified 135 monitoring 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?
Allied Universal Electronic Monitoring, headquartered in Leicester, tops this list with the largest team on record.
Which city has the most monitoring companies?
London leads with 23 headquartered companies, followed by Bristol (5) and Manchester (5).
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 270 verified decision-maker contacts tracked across these 135 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 20, 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.