Company lists · Data refreshed September 2026

Top 25 Security audit firms based in the United Kingdom

RevenueBase identified 465 company matches for security audit firms associated with the United Kingdom as of September 2026 and tracks 4,967 professional contacts across them, including 1,349 with verified work emails and 305 with mobile numbers. London is the largest hub.

This list covers company matches for security audit firms 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 6, 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 6, 2026 How this list was built
465Companies
4,967Contacts tracked
1,349Verified emails
305Mobile numbers
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The 25 largest security audit firms based in the United Kingdom

Ranked by team size
Top 25 of 465 company matches for security audit firms based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 6, 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 6, 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 6, 2026 · View company records in RevenueBase
2Exact matchLondon, United KingdomHQ recorded Sep 6, 2026201-500242 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
3Exact matchThatcham, United KingdomHQ recorded Sep 6, 202651-200159 contacts →

Exact match

“At Cyberfort we are passionate about the cyber security services we deliver for our customers which keeps their people, data, systems and technology infrastructure secure…”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
4Exact matchLondon, United KingdomHQ recorded Sep 6, 202651-200123 contacts →

Exact match

“Bulletproof is now part of WorkNest Secure.”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
5Exact matchWaterloo, United KingdomHQ recorded Sep 6, 202651-20080 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
6Exact matchHigh Wycombe, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
7Exact matchOxford, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
8Exact matchSouthampton, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
9Exact matchAlderley Edge, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
10Exact matchLondon, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
11Exact matchCardiff, United KingdomHQ recorded Sep 6, 202611-5049 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
12Exact matchCirencester, United KingdomHQ recorded Sep 6, 202611-5039 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
13Exact matchCheadle, United KingdomHQ recorded Sep 6, 202651-20038 contacts →

Exact match

“Mitigo Group keeps professional services firms safe from cyberattack and operationally resilient.”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
14Exact matchManchester, United KingdomHQ recorded Sep 6, 202611-5036 contacts →

Exact match

“Secarma exists to keep the world safe.”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
15Exact matchCrawley, United KingdomHQ recorded Sep 6, 202611-5035 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
16Exact matchStevenage, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
17Exact matchBirmingham, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
18Exact matchSolihull, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
19Exact matchCheltenham, United KingdomHQ recorded Sep 6, 202611-5031 contacts →

Exact match

“Salus is a provider of world-class cyber security services, enabling our clients to identify and manage their cyber risks proactively and effectively.”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
20Exact matchLancaster, United KingdomHQ recorded Sep 6, 202611-5030 contacts →

Exact match

“Cyber security can feel overwhelming.”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
21Exact matchPortsmouth, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
22Exact matchAltrincham, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase
23Exact matchLeeds, United KingdomHQ recorded Sep 6, 202611-5024 contacts →

Exact match

“Whatever you supply, design, build, manufacture, or grow, its excelling at it that has got your business to where it is today.”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
24Exact matchNewbury, United KingdomHQ recorded Sep 6, 202611-5023 contacts →

Exact match

“CyberCrowd are a market leader in the cyber security realm, offering everything from Assessment Services through to Pen Testing, CISOaaS, Certification Readiness, DPO services…”

Recorded in the RevenueBase company graph · Sep 6, 2026 · View company records in RevenueBase
25Exact matchCheltenham, United KingdomHQ recorded Sep 6, 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 6, 2026 · View company records in RevenueBase

Showing 25 of 465 security audit firms based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 1,349 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Security audit firms based in the United Kingdom at a glance

As of Sep 6, 2026
27.2%Verified-email coverage
6.1%Mobile-number coverage
10.7Average contacts per company
1-10Median size (employees)
35.1%Largest-city concentration · London
Sep 6, 2026Page data refreshed

Companies by employee count

1-10
303
11-50
128
51-200
26
201-500
4
501-1,000
3
5,001-10,000
1

Freshness & accuracy

How recently the business emails on this list were verified

Email last verified

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 firms” 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 1,349 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 6, 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 firms 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 firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many security audit firms are there based in the United Kingdom?

RevenueBase identified 465 company matches for security audit firms 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 audit firms?

London leads with 163 company records, followed by Manchester (22) and Birmingham (13).

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 1,349 professional contacts with verified work emails tracked across these 465 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 6, 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.