Company lists · Data refreshed September 2026

Top 25 Security assessments companies based in the United Kingdom

RevenueBase identified 384 company matches for security assessments companies associated with the United Kingdom as of September 2026 and tracks 4,884 professional contacts across them, including 789 with verified work emails. London is the largest hub.

This list covers company matches for security assessments companies associated with the United Kingdom, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 29, 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 RevenueBase SmartSearch · Exact Recorded Sep 29, 2026 How this list was built
384Companies
4,884Contacts tracked
789Verified emails
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The 25 largest security assessments companies based in the United Kingdom

Ranked by team size
Top 25 of 384 company matches for security assessments companies based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 29, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchLondon, United KingdomHQ recorded Sep 29, 2026n/a705 contacts →

Exact match

“Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
2Exact matchLeeds, United KingdomHQ recorded Sep 29, 20261,001-5,000180 contacts →

Exact match

“Established in 1978, Bridgegate Security is proud to be one of the UK’s largest independent security contractors.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
3Exact matchLeeds, United KingdomHQ recorded Sep 29, 202651-20099 contacts →

Exact match

“AppCheck is a Complete Enterprise Security Testing Solution that provides up to the minute vulnerability coverage for your entire estate.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
4Exact matchOxford, United KingdomHQ recorded Sep 29, 202651-20073 contacts →

Exact match

“Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
5Exact matchMaidenhead, United KingdomHQ recorded Sep 29, 202651-20072 contacts →

Exact match

“NSI is the UK’s most recognised certification body for fire and security.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
6Exact matchLondon, United KingdomHQ recorded Sep 29, 2026201-50058 contacts →

Exact match

“Black Diamond Security - Safeguarding Your World.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
7Exact matchBarnet, United KingdomHQ recorded Sep 29, 2026501-1,00058 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
8Exact matchAlderley Edge, United KingdomHQ recorded Sep 29, 202651-20057 contacts →

Exact match

“CyberLab is the UK-leading cyber security consultancy and managed services provider, trusted by over 1,200 enterprise businesses, government departments, and household names to…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
9Exact matchLondon, United KingdomHQ recorded Sep 29, 202651-20052 contacts →

Exact match

“At Hexegic we are not just passionate about protecting data through our Cyber services we are passionate about helping companies release the potential of the data they hold…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
10Exact matchSouth Normanton, United KingdomHQ recorded Sep 29, 2026201-50052 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
11Exact matchLondon, United KingdomHQ recorded Sep 29, 202651-20048 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
12Exact matchGodalming, United KingdomHQ recorded Sep 29, 202611-5040 contacts →

Exact match

“We are passionate about protecting the things that are important to our customers - their people or family, their properties, their possessions/contents and equipment.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
13Exact matchManchester, United KingdomHQ recorded Sep 29, 202611-5036 contacts →

Exact match

“Secarma exists to keep the world safe.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
14Exact matchCrawley, United KingdomHQ recorded Sep 29, 202611-5035 contacts →

Exact match

“ERGOS is an award-winning IT Managed Service Provider.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
15Exact matchStevenage, United KingdomHQ recorded Sep 29, 202651-20032 contacts →

Exact match

“Defense.com is transforming the way businesses manage cyber security by allowing them to easily identify, prioritise and remediate threats.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
16Exact matchBirmingham, United KingdomHQ recorded Sep 29, 202611-5032 contacts →

Exact match

“Aristi is a specialist provider of cyber security services with over 17 years of experience.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
17Exact matchSolihull, United KingdomHQ recorded Sep 29, 202611-5031 contacts →

Exact match

“SPECIALISTS IN IT SECURITY AND COMPLIANCE Our goal is to help customers define, develop and implement information security and compliance services, no matter what stage of the…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
18Exact matchPortsmouth, United KingdomHQ recorded Sep 29, 202611-5029 contacts →

Exact match

“Imagine a world where cyber threats are simply another challenge that you're fully equipped to handle.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
19Exact matchOxford, United KingdomHQ recorded Sep 29, 202611-5029 contacts →

Exact match

“Horus is a leading intelligence and security consultancy with a global, multilingual team of unrivalled experience, insight and operational expertise.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
20Exact matchLondon, United KingdomHQ recorded Sep 29, 202611-5028 contacts →

Exact match

“Priavo Security Group is an established provider of comprehensive security risk management, dedicated to safeguarding individuals, information, assets, and reputation through…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
21Exact matchCheltenham, United KingdomHQ recorded Sep 29, 202611-5026 contacts →

Exact match

“Prism Infosec is a CREST-approved member and Payment Card Industry Qualified Security Assessor Company based in Cheltenham and Liverpool, UK and was founded in 2006.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
22Exact matchNewbury, United KingdomHQ recorded Sep 29, 202611-5026 contacts →

Exact match

“We’re proud to be part of the Churches Fire & Security Group – a nationwide provider with a shared passion for fire safety and security.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
23Exact matchAltrincham, United KingdomHQ recorded Sep 29, 202611-5026 contacts →

Exact match

“Based in Manchester UK, we are an independent Cyber Security Consultancy providing Security services across a wide range of markets, from multi-national Corporate Organisations…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
24Exact matchWolverhampton, United KingdomHQ recorded Sep 29, 202651-20026 contacts →

Exact match

“Olympian provides a full range of security and risk management services with a core focus on commercial, retail and health care sectors.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
25Exact matchCheltenham, United KingdomHQ recorded Sep 29, 202611-5023 contacts →

Exact match

“AMR CyberSecurity delivers next generation cyber security services to assist organisations across a wide variety of sectors in understanding potential threats and effectively…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase

Showing 25 of 384 security assessments companies based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 789 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Security assessments companies based in the United Kingdom at a glance

As of Sep 29, 2026
16.2%Verified-email coverage
12.7Average contacts per company
1-10Median size (employees)
37.5%Largest-city concentration · London
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
225
11-50
113
51-200
31
201-500
7
501-1,000
5
1,001-5,000
2

Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 384 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

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
Company records associated with the United Kingdom whose business descriptions match “security assessments companies” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 789 professional contacts with verified work emails across the full matched dataset. 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 29, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Security assessments companies by metro

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “security assessments companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many security assessments companies are there based in the United Kingdom?

RevenueBase identified 384 company matches for security assessments companies associated with the United Kingdom as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

COBRA tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most security assessments companies?

London leads with 144 company records, followed by Manchester (12) and Birmingham (10).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 789 professional contacts with verified work emails tracked across these 384 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 29, 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.