Company lists · Data refreshed September 2026
Top 25 24/7 security monitoring services based in the United Kingdom
RevenueBase identified 438 24/7 security monitoring services headquartered in the United Kingdom as of September 2026 and tracks 3,328 professional contacts across them, including 580 with verified work emails. London is the largest hub.
This list covers 24/7 security monitoring services 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 27, 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 24/7 security monitoring services based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 89 contacts → | ||||
Partial evidence “For a better service and competitive price try K4 Security Services At K4 we offer the following: 1.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 64 contacts → | ||||
Partial evidence “City Security Services (CSS) have more than 25 years’ experience within the corporate security, public sector, education and social housing markets delivering manned guarding…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 52 contacts → | ||||
Strong evidence “Established in 1990, Ace Fire & Security is an end-to-end security, occupant safety, systems integration, monitoring and fire solutions specialist for commercial, industrial site…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 52 contacts → | ||||
Partial evidence “Secur-it is a leading provider of security services and risk management.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 51 contacts → | ||||
Partial evidence “Portal Security is a leading provider of security services dedicated to safeguarding individuals, businesses, and communities.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 49 contacts → | ||||
Indirect evidence “CSS is Scotland’s leading supplier and installer of domestic and commercial intruder and fire alarm systems.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 46 contacts → | ||||
Partial evidence “Risk Management Security Services specialise in providing bespoke security to commercial, residential and Industrial premises.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 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 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 40 contacts → | ||||
Indirect evidence “We are passionate about protecting the things that are important to our customers - their people or family, their properties, their possessions/contents and equipment.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 36 contacts → | ||||
Partial evidence “Doyle Security Ltd is a leading provider of professional security solutions, proudly safeguarding businesses, homeowners, and their properties for over four decades.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 36 contacts → | ||||
Indirect evidence “Based in Huddersfield, West Yorkshire.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 32 contacts → | ||||
Partial evidence “Zicam specialise in state-of-the-art security disciplines covering remotely monitored CCTV, Access Control, Fire Alarms, Permitter Protection and Intruder Alarm Systems.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 32 contacts → | ||||
Strong evidence “Intrinsic Security is a UK-headquartered cybersecurity firm delivering 24/7 threat detection, incident response, and resilience across cloud, hybrid, OT, IoT, and identity…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 32 contacts → | ||||
Partial evidence “Security Specialists A discreet, reliable and effective service Providing highly trained professional security guards and associated round the clock security services and for over…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 32 contacts → | ||||
Partial evidence “Security is what makes people feel most at ease.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 30 contacts → | ||||
Partial evidence “Many security companies pull together different providers to deliver a single service.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 29 contacts → | ||||
Strong evidence “Farsight Security Services is a market-leading provider of remote monitoring and ARC services.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 28 contacts → | ||||
Indirect evidence “Protecting homes and businesses since 1982.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 24 contacts → | ||||
Partial evidence “Close Protection Security is an industry-leading security company, established in 2017 and based in the North East of England, created by Glenn Bartlett.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 23 contacts → | ||||
Strong evidence “At Cougar Monitoring no matter if it's a residential, commercial or industry property, we can provide, install and full monitor a wide range of security solutions, such as; CCTV…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 23 contacts → | ||||
Partial evidence “part of the Obsequio Group At Brunel, we provide advanced security and life protection solutions, ensuring that your business and assets are safeguarded with the highest standards…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 22 contacts → | ||||
Partial evidence “Camera Security Services is a family owned and managed business which has been established since 1998; providing integrated security solutions to companies, local authorities…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 22 contacts → | ||||
Strong evidence “S P E C I A L I S T S E C U R I T Y S E R V I C E S Executive Security Solutions Ltd (ESS) is a specialist security services provider dedicated to delivering 24/7 protection for…” Source: RevenueBase Database · checked Sep 27, 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: 24/7 security monitoring services. 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 24/7 security monitoring services.
- Partial evidence
- Its own public description names part of 24/7 security monitoring services, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name 24/7 security monitoring services. 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 438 24/7 security monitoring services based in the United Kingdom
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24/7 security monitoring services based in the United Kingdom at a glance
As of Sep 27, 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 438 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 24/7 security monitoring services, 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 “24/7 security monitoring services”. 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 24/7 security monitoring services), 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 24/7 security monitoring services, 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, 580 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 27, 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.
24/7 security monitoring services by metro
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 24/7 security monitoring services, 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 24/7 security monitoring services are there based in the United Kingdom?
RevenueBase identified 438 24/7 security monitoring services 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?
The Keyholding Company, headquartered in London, tops this list with the largest team on record.
Which city has the most 24/7 security monitoring services?
London leads with 57 headquartered companies, followed by Manchester (10) and Glasgow (8).
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 580 verified decision-maker contacts tracked across these 438 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 27, 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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