Company lists · Data refreshed September 2026

Top 25 Security assessment companies based in the United Kingdom

RevenueBase identified 713 company matches for security assessment companies associated with the United Kingdom as of September 2026 and tracks 7,983 professional contacts across them, including 1,900 with verified work emails. London is the largest hub.

This list covers company matches for security assessment 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 27, 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 27, 2026 How this list was built
713Companies
7,983Contacts tracked
1,900Verified emails
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The 25 largest security assessment companies based in the United Kingdom

Ranked by team size
Top 25 of 713 company matches for security assessment companies based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 27, 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 27, 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 27, 2026 · View company records in RevenueBase
2Exact matchLondon, United KingdomHQ recorded Sep 27, 2026201-500242 contacts →

Exact match

“Obrela Security Industries is a global provider of cyber security services.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
3Exact matchLeeds, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
4Exact matchLondon, United KingdomHQ recorded Sep 27, 202651-200134 contacts →

Exact match

“Turnkey Consulting brings together people, protection, and performance to help the world’s leading companies understand and optimize their risk and security landscape.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
5Exact matchLondon, United KingdomHQ recorded Sep 27, 202651-200126 contacts →

Exact match

“We are TRPGLOBAL, your strategic partner in helping you with the complexities of risk management.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
6Exact matchLondon, United KingdomHQ recorded Sep 27, 202651-200123 contacts →

Exact match

“Bulletproof is now part of WorkNest Secure.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
7Exact matchHornchurch, United KingdomHQ recorded Sep 27, 2026501-1,000111 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
8Exact matchLeeds, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
9Exact matchLondon, United KingdomHQ recorded Sep 27, 2026201-50097 contacts →

Exact match

“As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
10Exact matchLeeds, United KingdomHQ recorded Sep 27, 202651-20090 contacts →

Exact match

“Solutions | Testing | Knowledge Helping You Protect Your Business From Cyber Attackers Your security and compliance partner, delivering trust worldwide Cognisys are your trusted…”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
11Exact matchWaterloo, United KingdomHQ recorded Sep 27, 202651-20080 contacts →

Exact match

“At Reliance Cyber, we believe in truly partnering with our customers.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
12Exact matchHigh Wycombe, United KingdomHQ recorded Sep 27, 202651-20074 contacts →

Exact match

“Saepio increase awareness, reduce risk and improve security in a continually evolving threat landscape.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
13Exact matchOxford, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
14Exact matchMaidenhead, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
15Exact matchLondon, United KingdomHQ recorded Sep 27, 202651-20061 contacts →

Exact match

“Intruder's continuous exposure management platform helps security, IT, and engineering teams stop breaches before they start.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
16Exact matchSouthampton, United KingdomHQ recorded Sep 27, 202651-20060 contacts →

Exact match

“Many organisations are dealing with multiple frameworks, overlapping tools, disconnected ownership, and increasing pressure from regulators, customers, and boards.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
17Exact matchLondon, United KingdomHQ recorded Sep 27, 2026201-50058 contacts →

Exact match

“Black Diamond Security - Safeguarding Your World.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
18Exact matchBarnet, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
19Exact matchAlderley Edge, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
20Exact matchLondon, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
21Exact matchSouth Normanton, United KingdomHQ recorded Sep 27, 2026201-50052 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
22Exact matchCardiff, United KingdomHQ recorded Sep 27, 202611-5049 contacts →

Exact match

“PureCyber is an award-winning, expert Cyber Security Consultancy.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase
23Exact matchLondon, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
24Exact matchGodalming, United KingdomHQ recorded Sep 27, 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 27, 2026 · View company records in RevenueBase
25Exact matchCirencester, United KingdomHQ recorded Sep 27, 202611-5039 contacts →

Exact match

“We help organisations understand, optimise, and strengthen their cybersecurity.”

Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase

Showing 25 of 713 security assessment companies based in the United Kingdom

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Security assessment companies based in the United Kingdom at a glance

As of Sep 27, 2026
23.8%Verified-email coverage
11.2Average contacts per company
1-10Median size (employees)
37.2%Largest-city concentration · London
Sep 27, 2026Page data refreshed

Companies by employee count

1-10
427
11-50
197
51-200
61
201-500
17
501-1,000
7
1,001-5,000
2
5,001-10,000
1

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 713 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 assessment 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 1,900 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 27, 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.

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 assessment companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

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

RevenueBase identified 713 company matches for security assessment 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 assessment companies?

London leads with 265 company records, followed by Manchester (27) and Birmingham (21).

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 1,900 professional contacts with verified work emails tracked across these 713 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 27, 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.