Company lists · Data refreshed September 2026
Top 25 Security monitoring service providers based in the United Kingdom
RevenueBase identified 1,145 security monitoring service providers headquartered in the United Kingdom as of September 2026 and tracks 103,554 professional contacts across them, including 5,523 with verified work emails and 8,590 with mobile numbers. London is the largest hub.
This list covers security monitoring service providers 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 6, 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 security monitoring service providers based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 79,699 contacts → | ||||
Partial evidence “G4S is a leading security and facility services company that provides proactive security services and cutting-edge smart technology to deliver tailored, integrated security…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 2 | 6,169 contacts → | ||||
Indirect evidence “Making the world a safer place.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 3 | 1,508 contacts → | ||||
Partial evidence “We are an intelligence-led security business.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 4 | 847 contacts → | ||||
Partial evidence “Corps Security - experts in security with social value Built on over 165 years of experience, Corps provides specialist security services, across the UK, to ensure the safety of…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 5 | 422 contacts → | ||||
Partial evidence “Unlike traditional security providers, we're redefining what protection means in today's world.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 6 | 419 contacts → | ||||
Partial evidence “Ward is an award winning, privately owned business, providing bespoke risk and security solutions including protective security personnel, explosive search dogs, narcotic search…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 7 | 392 contacts → | ||||
Indirect evidence “SSGC is a leading innovator in the Manned Guarding industry, specialising in the application of new technology to improve the performance of its Management team, deployed staff…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 8 | 326 contacts → | ||||
Indirect evidence “Kings Secure Technologies (KST) is a high-end, enterprise-level systems integrator.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 9 | 226 contacts → | ||||
Partial evidence “MAN Commercial is a leading security company and Training Academy based in Solihull, West Midlands.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 10 | 205 contacts → | ||||
Partial evidence “Pilgrims are a global security, risk management and service support company that identifies and manages risks for clients across all sectors, including oil & gas, telecoms…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 11 | 172 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 12 | 170 contacts → | ||||
Indirect evidence “Looking after the things people care about, wherever they are’.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 13 | 166 contacts → | ||||
Partial evidence “Providing Exceptional Security Services to Corporate and Retail Customers - Brooknight Security, with over 30 years of experience, is the go-to choice for businesses seeking…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 14 | 166 contacts → | ||||
Partial evidence “Trigion Security Services is the UK provider of Security Guarding and Technical Solutions for Facilicom UK.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 15 | 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 6, 2026Thanks. The Data Team will review it. | |||||
| 16 | 116 contacts → | ||||
Partial evidence “TSP has a reputation for providing enterprise security solutions, as well as excellent system integration standards and exceptional aftercare support, since its founding in 1988.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 17 | 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 6, 2026Thanks. The Data Team will review it. | |||||
| 18 | 87 contacts → | ||||
Partial evidence “Croma Security Solutions Group (CSSG) began in 1970 as a family-run business in Shirley, Southampton, known as County Locksmiths.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 19 | 85 contacts → | ||||
Partial evidence “At Servoca Secure Solutions, we take great pride in delivering a multi-service security business; offering a range of complementary products and services to both the public and…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 20 | 81 contacts → | ||||
Partial evidence “Nationwide Security providing both physical and electrical security services throughout the UK.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 21 | 80 contacts → | ||||
Partial evidence “T3 Security is a leading National Security Company supplying clients across the UK with bespoke security services.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 22 | 70 contacts → | ||||
Partial evidence “With over 50 years’ experience in the security industry, Abel has grown to become one of the UK’s largest privately owned providers of electronic security systems.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 23 | 69 contacts → | ||||
Indirect evidence “BauWatch secures your site and assets with rapidly deployed mobile video surveillance systems.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 24 | 69 contacts → | ||||
Partial evidence “Northern Security Ltd is a leading guarding, alarm response and electronic security business operating throughout the North of England and South West Scotland.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 25 | 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 6, 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: security monitoring service providers. 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 monitoring service providers.
- Partial evidence
- Its own public description names part of security monitoring service providers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name security monitoring service providers. 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 1,145 security monitoring service providers based in the United Kingdom
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Security monitoring service providers based in the United Kingdom at a glance
As of Sep 6, 2026Companies by employee count
Freshness & accuracy
How recently the business emails on this list were verified
Email last verified
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 monitoring service providers, 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 “security monitoring service providers”. 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 monitoring service providers), 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 monitoring service providers, 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, 5,523 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 6, 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 monitoring service providers 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 security monitoring service providers, 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 monitoring service providers are there based in the United Kingdom?
RevenueBase identified 1,145 security monitoring service providers 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?
G4s, headquartered in London, tops this list with the largest team on record.
Which city has the most security monitoring service providers?
London leads with 192 headquartered companies, followed by Manchester (29) and Birmingham (26).
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 5,523 verified decision-maker contacts tracked across these 1,145 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 6, 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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