Company lists · Data refreshed September 2026
Top 25 Security firms based in the United Kingdom
RevenueBase identified 3,630 security firms headquartered in the United Kingdom as of September 2026 and tracks 125,817 professional contacts across them, including 6,238 with verified work emails and 9,400 with mobile numbers. London is the largest hub.
This list covers security firms 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 firms based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 79,699 contacts → | ||||
Strong 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 | 1,451 contacts → | ||||
Strong evidence “TSS is the UK’s largest retail specialist security company, employing over 7500+ security personnel.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 3 | 1,265 contacts → | ||||
Strong evidence “With over 45 years of experience, Showsec is a leading name in the UK’s live event security sector.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 4 | 919 contacts → | ||||
Strong evidence “CIS Security is an independent security company equipped to help customers to solve the complex challenges in today’s digital, connected and regulated business world.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 5 | 884 contacts → | ||||
Strong evidence “Professional Security is one of the UK’s leading providers of security services, specialising in the hospitality and events sectors.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 6 | 852 contacts → | ||||
Strong evidence “VSG are one of the UK's leading security solutions providers with a heritage in manned guarding.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 7 | 847 contacts → | ||||
Strong 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. | |||||
| 8 | 765 contacts → | ||||
Strong evidence “Ranked in the top 1% of UK security companies, as approved by the Security Industry Authority, SecuriGroup is an award-winning security company, specialising in the provision of…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 9 | 649 contacts → | ||||
Indirect evidence “Established in 2003, FGH are trusted by international brands to keep their assets and millions of people safe every year.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 10 | 597 contacts → | ||||
Strong evidence “Part of ICTS Europe Group, ICTS UK & Ireland is a professional services firm which has been specialised in security risk for the past 39+ years.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 11 | 419 contacts → | ||||
Strong 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. | |||||
| 12 | 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. | |||||
| 13 | 389 contacts → | ||||
Strong evidence “Mitie Fire & Security is part of Mitie, the UK’s leading facilities management and professional services company, delivering integrated fire and security solutions that protect…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 14 | 326 contacts → | ||||
Strong evidence “Established in 1993, with commitment to our customers and staff alongside a strong ethos and standards driven approach, Regency Security is now the largest provider of door…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 15 | 285 contacts → | ||||
Indirect evidence “SES Group was founded in 1998 by Dr Tony Ball and rebranded as SES Group in 2014.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 16 | 232 contacts → | ||||
Indirect evidence “Established in 1994, Interr is a specialist agency providing intelligent guarding, reception, remote monitoring & response and front of house solutions within the retail, hotel…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 17 | 226 contacts → | ||||
Strong 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. | |||||
| 18 | 206 contacts → | ||||
Strong evidence “Wise Security is a trusted provider of professional security, crowd management, and safety solutions for high‑profile events, venues, and organisations across the UK.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 19 | 195 contacts → | ||||
Strong evidence “Surefire Business Protection No matter the sector you work in, or where you’re located in the UK, we can help you to make sure that fire and security problems are not things you…” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 20 | 180 contacts → | ||||
Strong evidence “Established in 1978, Bridgegate Security is proud to be one of the UK’s largest independent security contractors.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 21 | 175 contacts → | ||||
Strong evidence “We are able to supply a one stop security service for all types of security requirement.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 22 | 170 contacts → | ||||
Strong evidence “DeterTech is an industry leading provider of highly innovative and intelligence-led end-to-end security solutions.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 23 | 166 contacts → | ||||
Indirect evidence “We are GUK.” Source: RevenueBase Database · checked Sep 6, 2026Thanks. The Data Team will review it. | |||||
| 24 | 166 contacts → | ||||
Strong 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. | |||||
| 25 | 166 contacts → | ||||
Strong 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. | |||||
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 firms. 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 firms.
- Partial evidence
- Its own public description names part of security firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name security firms. 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 3,630 security firms based in the United Kingdom
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 6,238 reachable decision-makers.
Free signup · no credit card
Security firms 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 firms, 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 firms”. 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 firms), 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 firms, 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, 6,238 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 firms by metro
- Security firms in London740
- Security firms in Manchester92
- Security firms in Birmingham81
- Security firms in Leeds50
- Security firms in Bristol43
- Security firms in Glasgow40
- Security firms in Liverpool38
- Security firms in Leicester25
- Security firms in Sheffield25
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 firms, 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 firms are there based in the United Kingdom?
RevenueBase identified 3,630 security firms 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 firms?
London leads with 740 headquartered companies, followed by Manchester (92) and Birmingham (81).
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 6,238 verified decision-maker contacts tracked across these 3,630 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.
Ready to reach these companies? Verified emails and direct dials for all 3,630 security firms based in the United Kingdom. Start with a free account, no credit card.
Download this list →Related lists
Security firms by geography
- Security firms based in the United States
- Security firms based in Brazil
- Security firms based in France
- Security firms based in Canada
- Security firms based in Germany
- Security firms based in Italy
- Security firms based in Australia
- Security firms based in the Netherlands
- Security firms based in South Africa
- Security firms based in Mexico
- Security firms based in Spain
- Security firms based in Argentina
Browse the directory
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.