Company lists · Data refreshed September 2026

Top 25 Government security contractors based in the United Kingdom

RevenueBase identified 799 government security contractors headquartered in the United Kingdom as of September 2026 and tracks 13,670 professional contacts across them, including 1,192 with verified work emails and 673 with mobile numbers. London is the largest hub.

This list covers government security contractors 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, how directly it supports the match, and when it was last checked. Data refreshed September 3, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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.

How to read this list HQ checked on every row Match evidence on every row Refreshed Sep 3, 2026 86% judged on-target in blind review
799Companies
13,670Contacts tracked
1,192Verified emails
673Mobile numbers
Unlock all 799 companies Free signup · no credit card · 500 free credits

The 25 largest government security contractors based in the United Kingdom

Ranked by team size
Top 25 of 799 government security contractors based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 3, 2026. Evidence rates how directly each company's own description names government security contractors: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
SecurigroupPartial evidence
United KingdomHQ checked Sep 3, 20261,001-5,000761

“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: company website · checked Sep 3, 2026
2
FGH SecurityIndirect evidence
Manchester, United KingdomHQ checked Sep 3, 20261,001-5,000650

“Established in 2003, FGH are trusted by international brands to keep their assets and millions of people safe every year.”

Source: company website · checked Sep 3, 2026
3
Icts UK & IrelandPartial evidence
London, United KingdomHQ checked Sep 3, 20261,001-5,000593

“Part of ICTS Europe Group, ICTS UK & Ireland is a professional services firm which has been specialised in security risk for the past 38+ years.”

Source: company website · checked Sep 3, 2026
4
Regency SecurityPartial evidence
Braintree, United KingdomHQ checked Sep 3, 20261,001-5,000325

“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: company website · checked Sep 3, 2026
5London, United KingdomHQ checked Sep 3, 2026501-1,000204

“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: company website · checked Sep 3, 2026
6Wembley, United KingdomHQ checked Sep 3, 2026201-500175

“We are able to supply a one stop security service for all types of security requirement.”

Source: company website · checked Sep 3, 2026
7
Vespasian SecurityPartial evidence
Portsmouth, United KingdomHQ checked Sep 3, 2026201-500125

“Vespasian Security was formed in February 2006.”

Source: company website · checked Sep 3, 2026
8Hornchurch, United KingdomHQ checked Sep 3, 2026501-1,000111

“We are a well-established company that supplies specialist Close Protection, Door Supervisor services to Private Individuals, Visiting Royal Families, Government Officials…”

Source: company website · checked Sep 3, 2026
9
Consortio SecurityIndirect evidence
Castle Donington, United KingdomHQ checked Sep 3, 2026501-1,000107

“Protecting People, Property, Assets & Brands.”

Source: company website · checked Sep 3, 2026
10
Octavian SecurityPartial evidence
Bingham, United KingdomHQ checked Sep 3, 2026201-50091

“The multi award winning Octavian is one of the world's fastest growing, most forward thinking security and facilities management led businesses.”

Source: company website · checked Sep 3, 2026
11
K4 Security - K4 GroupPartial evidence
Hounslow, United KingdomHQ checked Sep 3, 2026201-50090

“For a better service and competitive price try K4 Security Services At K4 we offer the following: 1.”

Source: company website · checked Sep 3, 2026
12Whiteley, United KingdomHQ checked Sep 3, 2026501-1,00087

“Croma Security Solutions Group (CSSG) began in 1970 as a family-run business in Shirley, Southampton, known as County Locksmiths.”

Source: company website · checked Sep 3, 2026
13
T3 SecurityPartial evidence
Seaton Burn, United KingdomHQ checked Sep 3, 2026501-1,00081

“T3 Security is a leading National Security Company supplying clients across the UK with bespoke security services.”

Source: company website · checked Sep 3, 2026
14
Knight ProtectionPartial evidence
Camberley, United KingdomHQ checked Sep 3, 2026201-50080

“Knight Protection has nearly three decades’ experience providing bespoke protection and security solutions to private individuals, private estates, and corporate and public sector…”

Source: company website · checked Sep 3, 2026
15
Northern Security LTDPartial evidence
Carlisle, United KingdomHQ checked Sep 3, 2026201-50070

“Northern Security Ltd is a leading guarding, alarm response and electronic security business operating throughout the North of England and South West Scotland.”

Source: company website · checked Sep 3, 2026
16
Britsafe LimitedPartial evidence
York, United KingdomHQ checked Sep 3, 2026501-1,00066

“Welcome to Britsafe Limited Years of Security and Cleaning experience have made us masters in providing defect-free security and cleaning solutions tailor-made to suit the…”

Source: company website · checked Sep 3, 2026
17London, United KingdomHQ checked Sep 3, 2026201-50064

“Vigilance is a pioneering security company with a proud military heritage.”

Source: company website · checked Sep 3, 2026
18London, United KingdomHQ checked Sep 3, 2026201-50064

“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: company website · checked Sep 3, 2026
19
Black Diamond SecurityPartial evidence
London, United KingdomHQ checked Sep 3, 2026201-50062

“Black Diamond Security - Safeguarding Your World.”

Source: company website · checked Sep 3, 2026
20Barnet, United KingdomHQ checked Sep 3, 2026501-1,00060

“In today’s advanced, interconnected world, protecting the infrastructure that allows society to function is crucial.”

Source: company website · checked Sep 3, 2026
21
Sentinel Group SecurityPartial evidence
Loughton, United KingdomHQ checked Sep 3, 2026201-50058

“Sentinel Group Security is a fast growing provider of all aspects of security personnel and manned security services operating across the United Kingdom.”

Source: company website · checked Sep 3, 2026
22
Portal SecurityPartial evidence
Glasgow, United KingdomHQ checked Sep 3, 2026201-50052

“Portal Security is a leading provider of security services dedicated to safeguarding individuals, businesses, and communities.”

Source: company website · checked Sep 3, 2026
23South Normanton, United KingdomHQ checked Sep 3, 2026201-50052

“Secur-it is a leading provider of security services and risk management.”

Source: company website · checked Sep 3, 2026
24
Right Guard SecurityPartial evidence
Canterbury, United KingdomHQ checked Sep 3, 2026201-50050

“Right Guard Security was formed in 1990 in response to an escalation of public order and crowd safety related issues within the entertainment industry along with meeting the…”

Source: company website · checked Sep 3, 2026
25
UK Protection LTDPartial evidence
London, United KingdomHQ checked Sep 3, 2026201-50044

“UK Protection is widely recognised as the premier supplier of security solutions to the Corporate, Jewellery and Luxury Retail industries across the UK.”

Source: company website · checked Sep 3, 2026

Showing 25 of 799 government security contractors based in the United Kingdom

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Government security contractors based in the United Kingdom at a glance

As of Sep 3, 2026
11-50Median size (employees)
LondonLargest hub · 251 HQs
673Contacts with mobile numbers
Sep 3, 2026Data refreshed

Companies by employee count

1-10
216
11-50
265
51-200
200
201-500
65
501-1,000
18
1,001-5,000
16
10001+
3

Verified emails by last verification

0–30
0
31–60
109
61–90
692
90–180
382
180+
9

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 government security contractors, so some rows will be adjacent to the category rather than pure plays. The description and evidence 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 SmartSearch, 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 “government security contractors”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among government security contractors, 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 an evidence 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, 1,192 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 3, 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.

Government security contractors by metro

  • Government security contractors in London251
  • Government security contractors in Birmingham27
  • Government security contractors in Manchester25

Frequently asked

How many government security contractors are there based in the United Kingdom?

RevenueBase identified 799 government security contractors 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?

Securigroup, headquartered in United Kingdom, tops this list with the largest team on record.

Which city has the most government security contractors?

London leads with 251 headquartered companies, followed by Birmingham (27) and Manchester (25).

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 1,192 verified decision-maker contacts tracked across these 799 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 3, 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 SmartSearch, 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.