Company lists · Data refreshed November 2026

Top 24 Security audit and assessment services based in the United Kingdom

RevenueBase identified 374 company matches for security audit and assessment services associated with the United Kingdom as of November 2026 and tracks 4,571 professional contacts across them, including 1,051 with verified work emails. London is the largest hub.

This list covers company matches for security audit and assessment services 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 November 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 RevenueBase SmartSearch · Exact Recorded Nov 5, 2026 How this list was built
374Companies
4,571Contacts tracked
1,051Verified emails
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The 24 largest security audit and assessment services based in the United Kingdom

Ranked by team size
Top 24 of 374 company matches for security audit and assessment services based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 5, 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 Nov 5, 2026n/a782 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 · Nov 5, 2026 · View company records in RevenueBase
2Exact matchFareham, United KingdomHQ recorded Nov 5, 202651-200129 contacts →

Exact match

“Relax.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
3Exact matchLeeds, United KingdomHQ recorded Nov 5, 202651-200120 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 · Nov 5, 2026 · View company records in RevenueBase
4Exact matchLondon, United KingdomHQ recorded Nov 5, 2026201-500104 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 · Nov 5, 2026 · View company records in RevenueBase
5Exact matchWaterloo, United KingdomHQ recorded Nov 5, 202651-20084 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
6Exact matchOxford, United KingdomHQ recorded Nov 5, 202651-20076 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 · Nov 5, 2026 · View company records in RevenueBase
7Exact matchSouthampton, United KingdomHQ recorded Nov 5, 202651-20072 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 · Nov 5, 2026 · View company records in RevenueBase
8Exact matchMacclesfield, United KingdomHQ recorded Nov 5, 202651-20064 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 · Nov 5, 2026 · View company records in RevenueBase
9Exact matchManchester, United KingdomHQ recorded Nov 5, 202611-5042 contacts →

Exact match

“Secarma exists to keep the world safe.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
10Exact matchBirmingham, United KingdomHQ recorded Nov 5, 202611-5037 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
11Exact matchSolihull, United KingdomHQ recorded Nov 5, 202611-5035 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 · Nov 5, 2026 · View company records in RevenueBase
12Exact matchCambridge, United KingdomHQ recorded Nov 5, 202611-5032 contacts →

Exact match

“Pentesting Exams by Pentesting Experts.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
13Exact matchBristol, United KingdomHQ recorded Nov 5, 202611-5031 contacts →

Exact match

“We help Defence, Government and highly regulated organisations solve complex cyber security and information assurance challenges, from Secure by Design and security architecture…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
14Exact matchEly, United KingdomHQ recorded Nov 5, 202651-20031 contacts →

Exact match

“GRC International Group plc is the holding company for a group of companies providing a range of products and services to address the IT governance, risk management and compliance…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
15Exact matchPortsmouth, United KingdomHQ recorded Nov 5, 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 · Nov 5, 2026 · View company records in RevenueBase
16Exact matchAltrincham, United KingdomHQ recorded Nov 5, 202611-5029 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 · Nov 5, 2026 · View company records in RevenueBase
17Exact matchCheltenham, United KingdomHQ recorded Nov 5, 202611-5026 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 · Nov 5, 2026 · View company records in RevenueBase
18Exact matchLeeds, United KingdomHQ recorded Nov 5, 202611-5023 contacts →

Exact match

“Halo I.S is not just another cybersecurity organization based in the UK; we're a testament to evolution and client-centric innovation.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
19Exact matchWrea Green, United KingdomHQ recorded Nov 5, 202611-5021 contacts →

Exact match

“Critec Group is an independent security risk consultancy, specialising in comprehensive security risk, threat, and vulnerability analysis, as well as security mitigation design…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
20Exact matchDerry/londonderry, United KingdomHQ recorded Nov 5, 20261-1019 contacts →

Exact match

“Safe Harbour Security specialise in penetration testing, ISO consultancy, and governance, risk, and compliance (GRC) services.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
21Exact matchWimbledon, United KingdomHQ recorded Nov 5, 202611-5018 contacts →

Exact match

“We are dedicated to advancing cyber security through meticulous assessment of products and services engineered to detect and thwart cyber attacks.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
22Exact matchLondon, United KingdomHQ recorded Nov 5, 202611-5018 contacts →

Exact match

“Our aim is to help businesses prepare for security audits and maintain ongoing compliance efficiently and effectively.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
23Exact matchLondon, United KingdomHQ recorded Nov 5, 202611-5018 contacts →

Exact match

“RedSecLabs, with its global team of highly respected cybersecurity experts, offers world-class and top-tier cybersecurity consulting services.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
24Exact matchHalesowen, United KingdomHQ recorded Nov 5, 202611-5017 contacts →

Exact match

“Advent IM is the UK’s leading independent GRC information and physical security consultancy and training provider.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase

Showing 24 of 374 security audit and assessment services based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 1,051 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Security audit and assessment services based in the United Kingdom at a glance

As of Nov 5, 2026
23.0%Verified-email coverage
12.2Average contacts per company
1-10Median size (employees)
34.2%Largest-city concentration · London
Nov 5, 2026Page data refreshed

Companies by employee count

1-10
253
11-50
89
51-200
19
201-500
8
501-1,000
2
1,001-5,000
1
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 374 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 audit and assessment services” 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 1,051 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 November 5, 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 audit and assessment services 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 audit and assessment services”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many security audit and assessment services are there based in the United Kingdom?

RevenueBase identified 374 company matches for security audit and assessment services associated with the United Kingdom as of November 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 audit and assessment services?

London leads with 128 company records, followed by Birmingham (8) and Manchester (8).

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 1,051 professional contacts with verified work emails tracked across these 374 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 November 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.