Company lists · Data refreshed September 2026

Top 23 Private security firms based in London, United Kingdom

RevenueBase identified 549 private security firms headquartered in London, United Kingdom as of September 2026 and tracks 88,317 professional contacts across them, including 1,094 with verified work emails. London is the largest hub.

This list covers private security firms headquartered in London, 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 5, 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 5, 2026 86% judged on-target in blind review
549Companies
88,317Contacts tracked
1,094Verified emails
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The 23 largest private security firms based in London, United Kingdom

Ranked by team size
Top 23 of 549 private security firms based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names private security firms: 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
G4sPartial evidence
London, United KingdomHQ checked Sep 5, 202610001+79,699

“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: company website · checked Sep 5, 2026
2London, United KingdomHQ checked Sep 5, 20265,001-10,0001,451

“TSS is the UK’s largest retail specialist security company, employing over 7500+ security personnel.”

Source: company website · checked Sep 5, 2026
3
CIS Security LimitedPartial evidence
London, United KingdomHQ checked Sep 5, 20261,001-5,000919

“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: company website · checked Sep 5, 2026
4
Corps SecurityPartial evidence
London, United KingdomHQ checked Sep 5, 20261,001-5,000847

“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: company website · checked Sep 5, 2026
5
Ward SecurityStrong evidence
London, United KingdomHQ checked Sep 5, 20261,001-5,000419

“Ward is an award winning, privately owned business, providing bespoke risk and security solutions including protective security personnel, explosive search dogs, narcotic search…”

Source: company website · checked Sep 5, 2026
6
InterrIndirect evidence
London, United KingdomHQ checked Sep 5, 20261,001-5,000232

“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: company website · checked Sep 5, 2026
7
The Keyholding CompanyPartial evidence
London, United KingdomHQ checked Sep 5, 202651-200137

“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: company website · checked Sep 5, 2026
8London, United KingdomHQ checked Sep 5, 202651-20085

“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: company website · checked Sep 5, 2026
9London, United KingdomHQ checked Sep 5, 202651-20075

“We are Veteran Owned, Veteran Operated Security company based in London (HQ), with operation nationwide.”

Source: company website · checked Sep 5, 2026
10
KK Security & FM LTDPartial evidence
London, United KingdomHQ checked Sep 5, 2026201-50071

“KK Security was established in 2014 with the goal of keeping people safe.”

Source: company website · checked Sep 5, 2026
11
Saladin SecurityPartial evidence
London, United KingdomHQ checked Sep 5, 202651-20064

“Saladin is a security services and risk management company, operating mainly in complex and unstable regions of the world.”

Source: company website · checked Sep 5, 2026
12London, United KingdomHQ checked Sep 5, 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 5, 2026
13London, United KingdomHQ checked Sep 5, 2026201-50063

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

Source: company website · checked Sep 5, 2026
14
Black Diamond SecurityPartial evidence
London, United KingdomHQ checked Sep 5, 2026201-50058

“Black Diamond Security - Safeguarding Your World.”

Source: company website · checked Sep 5, 2026
15
GSA GlobalPartial evidence
London, United KingdomHQ checked Sep 5, 202611-5049

“GSA Global helps organisations, families and individuals respond to serious, complex and emerging security risks.”

Source: company website · checked Sep 5, 2026
16
Frankton Group LTDIndirect evidence
London, United KingdomHQ checked Sep 5, 202651-20048

“In today’s complex threat environment, businesses, individuals, and organisations require trusted partners to provide the ultimate assurance that their assets are well protected.”

Source: company website · checked Sep 5, 2026
17
UK Protection LTDPartial evidence
London, United KingdomHQ checked Sep 5, 2026201-50045

“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 5, 2026
18London, United KingdomHQ checked Sep 5, 2026501-1,00043

“AK9 Security and FM Solutions offers comprehensive security solutions for businesses, governmental organizations, and residential areas.”

Source: company website · checked Sep 5, 2026
19
Pathway Risk ManagementPartial evidence
London, United KingdomHQ checked Sep 5, 202651-20040

“Pathway Risk Management delivers risk-led security and resilience solutions to organisations across the UK and internationally.”

Source: company website · checked Sep 5, 2026
20London, United KingdomHQ checked Sep 5, 202651-20039

“Gratte Brothers is an experienced provider of integrated security solutions, which are Built on Strong Values and ultimately deliver a measurable return on investment.”

Source: company website · checked Sep 5, 2026
21
BML GroupPartial evidence
London, United KingdomHQ checked Sep 5, 202611-5037

“Founded in 2015, BML Group is one of the UK's leading Security & Facilities Management providers, delivering tailored solutions that enhance operational efficiency and safety.”

Source: company website · checked Sep 5, 2026
22
HARODPartial evidence
London, United KingdomHQ checked Sep 5, 202611-5036

“Harod Associates delivers global investigation and security solutions to complex crime and risk issues.”

Source: company website · checked Sep 5, 2026
23
Team Fusion LTDPartial evidence
London, United KingdomHQ checked Sep 5, 202611-5034

“Our elite teams offer bespoke, integrated security solutions that adapt and react to the evolving threat landscape.”

Source: company website · checked Sep 5, 2026

Showing 23 of 549 private security firms based in London, United Kingdom

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Private security firms based in London, United Kingdom at a glance

As of Sep 5, 2026
11-50Median size (employees)
LondonLargest hub · 549 HQs
Contacts with mobile numbers
Sep 5, 2026Data refreshed

Companies by employee count

1-10
180
11-50
177
51-200
135
201-500
32
501-1,000
11
1,001-5,000
7
5,001-10,000
2
10001+
3

Email recency for this list is measured across the whole United Kingdom list rather than this city, so it is reported there. Company counts and contact totals on this page are exact for London, over 549 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 private security firms, 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 London, United Kingdom whose own description of what they do matches “private security firms”. 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 private security firms, and records with no verified work email. Companies headquartered outside London 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, 1,094 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 5, 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.

Private security firms by metro in the United Kingdom

Frequently asked

How many private security firms are there based in London, United Kingdom?

RevenueBase identified 549 private security firms headquartered in London, 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 private security firms?

London leads with 549 headquartered companies, followed by Birmingham (45) and Manchester (45).

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 1,094 verified decision-maker contacts tracked across these 549 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 5, 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.