Company lists · Data refreshed September 2026

Top 25 Government contract security companies based in the United Kingdom

Name: Government contract security companies based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 3, 2026 266 companies tracked

RevenueBase identified 266 government contract security companies headquartered in the United Kingdom as of September 2026 and tracks 3,436 professional contacts across them, including 293 with verified work emails and 181 with mobile numbers. London is the largest hub.

This list covers government contract security 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 3, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 3, 2026 86% judged on-target in blind review

266Companies

3,436Contacts tracked

293Verified emails

181Mobile numbers

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The 25 largest government contract security companies based in the United Kingdom

Ranked by team size

Top 25 of 266 government contract security companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 3, 2026. RevenueBase Smart Search rates how each company's information relates to government contract security companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Regency Security	Partial evidence	Braintree, United KingdomHQ checked Sep 3, 2026	1,001-5,000	325 contacts →
	Partial 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 3, 2026
2	Vespasian Security	Partial evidence	Portsmouth, United KingdomHQ checked Sep 3, 2026	201-500	125 contacts →
	Partial evidence “Vespasian Security was formed in February 2006.” Source: RevenueBase Database · checked Sep 3, 2026
3	Kingdom Security Services	Partial evidence	Newton-Le-Willows, United KingdomHQ checked Sep 3, 2026	5,001-10,000	124 contacts →
	Partial evidence “About Kingdom Security Established in March 1993, Kingdom Security is a leading UK security provider delivering professional, fully licensed security services nationwide.” Source: RevenueBase Database · checked Sep 3, 2026
4	Octavian Security	Partial evidence	Bingham, United KingdomHQ checked Sep 3, 2026	201-500	91 contacts →
	Partial evidence “The multi award winning Octavian is one of the world's fastest growing, most forward thinking security and facilities management led businesses.” Source: RevenueBase Database · checked Sep 3, 2026
5	K4 Security - K4 Group	Partial evidence	Hounslow, United KingdomHQ checked Sep 3, 2026	201-500	90 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 3, 2026
6	Servoca Secure Solutions Limited	Partial evidence	London, United KingdomHQ checked Sep 3, 2026	51-200	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 3, 2026
7	Northern Security LTD	Partial evidence	Carlisle, United KingdomHQ checked Sep 3, 2026	201-500	70 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 3, 2026
8	City Security Services Part Of City Group Security	Partial evidence	London, United KingdomHQ checked Sep 3, 2026	201-500	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 3, 2026
9	Black Diamond Security	Partial evidence	London, United KingdomHQ checked Sep 3, 2026	201-500	62 contacts →
	Partial evidence “Black Diamond Security - Safeguarding Your World.” Source: RevenueBase Database · checked Sep 3, 2026
10	Sentinel Group Security	Partial evidence	Loughton, United KingdomHQ checked Sep 3, 2026	201-500	58 contacts →
	Partial evidence “Sentinel Group Security is a fast growing provider of all aspects of security personnel and manned security services operating across the United Kingdom.” Source: RevenueBase Database · checked Sep 3, 2026
11	Phoenix FMS	Partial evidence	Newcastle Upon Tyne, United KingdomHQ checked Sep 3, 2026	201-500	44 contacts →
	Partial evidence “Design, install and maintain CCTV Systems Intruder Systems Access Control Manned Security Guarding Event Stewarding Construction Cleaning Commercial Cleaning Builders & Sparkle…” Source: RevenueBase Database · checked Sep 3, 2026
12	AIB Group	Partial evidence	Park Bletchley, United KingdomHQ checked Sep 3, 2026	201-500	43 contacts →
	Partial evidence “All in Black are an accredited security solutions provider with over 20 years’ experience at the highest level across the UK.” Source: RevenueBase Database · checked Sep 3, 2026
13	Ak9 Security And FM Solutions LTD	Strong evidence	London, United KingdomHQ checked Sep 3, 2026	501-1,000	43 contacts →
	Strong evidence “AK9 Security and FM Solutions offers comprehensive security solutions for businesses, governmental organizations, and residential areas.” Source: RevenueBase Database · checked Sep 3, 2026
14	4 Site Security	Partial evidence	Leeds, United KingdomHQ checked Sep 3, 2026	51-200	40 contacts →
	Partial evidence “4 Site Security have specialised in providing professional security services to clients throughout the North of England for over 23 Years.” Source: RevenueBase Database · checked Sep 3, 2026
15	Leisure Guard Security UK LTD	Partial evidence	Manchester, United KingdomHQ checked Sep 3, 2026	201-500	33 contacts →
	Partial evidence “At Leisure Guard Security, we provide a wide range of security services to private individuals and corporate businesses alike.” Source: RevenueBase Database · checked Sep 3, 2026
16	OAK Security Services Limited	Partial evidence	Ilford, United KingdomHQ checked Sep 3, 2026	201-500	32 contacts →
	Partial evidence “Oak Security Services was founded in July 2015 and is now one of the fastest growing security companies in the UK.” Source: RevenueBase Database · checked Sep 3, 2026
17	Prosec UK	Partial evidence	Doncaster, United KingdomHQ checked Sep 3, 2026	51-200	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 3, 2026
18	Samson Security Fire & Facilities	Partial evidence	Liverpool, United KingdomHQ checked Sep 3, 2026	51-200	32 contacts →
	Partial evidence “At Samson Security Fire & Facilities, we provide integrated security, fire protection, and facilities management solutions designed to keep people, property, and operations safe…” Source: RevenueBase Database · checked Sep 3, 2026
19	Herongrange Group Limited	Indirect evidence	Burton Upon Trent, United KingdomHQ checked Sep 3, 2026	201-500	31 contacts →
	Indirect evidence “At Herongrange we pride ourselves in delivering our products and services to the highest possible standards.” Source: RevenueBase Database · checked Sep 3, 2026
20	Systematic Security LTD	Partial evidence	London, United KingdomHQ checked Sep 3, 2026	201-500	31 contacts →
	Partial evidence “Systematic Security deliver static manned guarding, mobile patrols, open and lock ups, keyholding and emergency response requirements as well as Vacant Property inspections to a…” Source: RevenueBase Database · checked Sep 3, 2026
21	Eboracum	Indirect evidence	York, United KingdomHQ checked Sep 3, 2026	201-500	27 contacts →
	Indirect evidence “Eboracum was founded in 2011 and established in York by local-lad and former North Yorkshire Police Constable Carl Nickson.” Source: RevenueBase Database · checked Sep 3, 2026
22	Glevum Security	Partial evidence	Gloucester, United KingdomHQ checked Sep 3, 2026	51-200	25 contacts →
	Partial evidence “We deliver professional, accredited security services that protect people, property, and organisations across the UK.” Source: RevenueBase Database · checked Sep 3, 2026
23	Close Protection Security NE	Partial evidence	Darlington, United KingdomHQ checked Sep 3, 2026	51-200	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 3, 2026
24	Classic Services Group LTD	Partial evidence	Crawley, United KingdomHQ checked Sep 3, 2026	51-200	21 contacts →
	Partial evidence “Classic Security was founded in 1947 by Fredrick Townsley - the father of our chairman and the grandfather of our MD.” Source: RevenueBase Database · checked Sep 3, 2026
25	Secured Security Solutions Limited	Indirect evidence	Ilford, United KingdomHQ checked Sep 3, 2026	51-200	20 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 3, 2026

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: government contract security 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 government contract security companies.
Partial evidence: Its own public description names part of government contract security companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name government contract security 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 266 government contract security companies based in the United Kingdom

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Government contract security companies based in the United Kingdom at a glance

As of Sep 3, 2026

8.5%Verified-email coverage

5.3%Mobile-number coverage

12.9Average contacts per company

11-50Median size (employees)

25.6%Largest-city concentration · London

Sep 3, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

Freshness & accuracy

How recently the business emails on this list were verified

Email last verified

00–30

3331–60

16861–90

9090–180

2180+

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 contract security 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 “government contract security 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 government contract security 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 government contract security 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, 293 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 contract security companies by metro

Government contract security companies in London68

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 government contract security 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 government contract security companies are there based in the United Kingdom?

RevenueBase identified 266 government contract security 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?

Regency Security, headquartered in Braintree, tops this list with the largest team on record.

Which city has the most government contract security companies?

London leads with 68 headquartered companies, followed by Manchester (12) and Birmingham (12).

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 293 verified decision-maker contacts tracked across these 266 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 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.