Company lists · Data refreshed September 2026

Top 25 Third party security audit companies based in the United Kingdom

RevenueBase identified 206 company matches for third party security audit companies associated with the United Kingdom as of September 2026 and tracks 2,412 professional contacts across them, including 629 with verified work emails. London is the largest hub.

This list covers company matches for third party security audit 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
206Companies
2,412Contacts tracked
629Verified emails
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The 25 largest third party security audit companies based in the United Kingdom

Ranked by team size
Top 25 of 206 company matches for third party security audit 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 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
2Exact matchWaterloo, United KingdomHQ recorded Sep 29, 202651-20080 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
3Exact 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
4Exact 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
5Exact 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
6Exact matchCambridge, United KingdomHQ recorded Sep 29, 202611-5034 contacts →

Exact match

“Pentesting Exams by Pentesting Experts.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
7Exact 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
8Exact 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
9Exact 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
10Exact 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
11Exact 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
12Exact matchNewbury, United KingdomHQ recorded Sep 29, 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 29, 2026 · View company records in RevenueBase
13Exact matchLondon, United KingdomHQ recorded Sep 29, 202611-5023 contacts →

Exact match

“Toro was founded on creating the UK's first Red Team penetration test - and then attacking hundreds of clients by hacking their systems, influencing / social engineering staff and…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
14Exact matchBasingstoke, United KingdomHQ recorded Sep 29, 202611-5020 contacts →

Exact match

“We help organisations achieve business-focused cybersecurity compliance across various industry and regulatory frameworks with successful stakeholder management, particularly in…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
15Exact matchLondon, United KingdomHQ recorded Sep 29, 202611-5020 contacts →

Exact match

“Secure Purple is a leading cyber security and digital safety firm that provides innovative solutions and services to help organisations and individuals stay protected in the…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
16Exact matchTunbridge Wells, United KingdomHQ recorded Sep 29, 202611-5019 contacts →

Exact match

“Razorthorn Security is a specialist cybersecurity consultancy founded in 2007, with nearly two decades of experience helping organisations protect their data, their systems and…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
17Exact matchWimbledon, United KingdomHQ recorded Sep 29, 202611-5019 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 · Sep 29, 2026 · View company records in RevenueBase
18Exact matchLeeds, United KingdomHQ recorded Sep 29, 202611-5019 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 · Sep 29, 2026 · View company records in RevenueBase
19Exact matchLondon, United KingdomHQ recorded Sep 29, 202611-5015 contacts →

Exact match

“is an ISO 9001:2015 and ISO/IEC 27001:2022 certified, DPIIT-recognized cybersecurity company delivering structured External Vulnerability Assessment & Penetration Testing (VAPT)…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
20Exact matchLondon, United KingdomHQ recorded Sep 29, 202611-5014 contacts →

Exact match

“Demand more from your AI & Data Security partner.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
21Exact matchLondon, United KingdomHQ recorded Sep 29, 202611-5014 contacts →

Exact match

“Risk Crew is known for their vision, innovative thinking and facility to embrace change.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
22Exact matchMilton Keynes, United KingdomHQ recorded Sep 29, 202611-5012 contacts →

Exact match

“We offer specialist CREST & CHECK Approved Penetration Testing services in order to secure our clients most critical assets.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
23Exact matchBelfast, United KingdomHQ recorded Sep 29, 202611-5012 contacts →

Exact match

“Cyber Guarded is a vendor independent business which provides Cyber Security auditing and testing services.”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
24Exact matchWinchester, United KingdomHQ recorded Sep 29, 202611-5012 contacts →

Exact match

“Security Consultants at Infosec Partners are formally trained to a high degree, having at least one of the following Security Management certifications: CESG CLAS, CISSP, CISM…”

Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
25Exact matchBath, United KingdomHQ recorded Sep 29, 202611-5011 contacts →

Exact match

“At Mobius Binary we care about your reputation and the loss that could result from violating your digital boundaries.”

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

Showing 25 of 206 third party security audit companies based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 629 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Third party security audit companies based in the United Kingdom at a glance

As of Sep 29, 2026
26.1%Verified-email coverage
11.7Average contacts per company
1-10Median size (employees)
32.0%Largest-city concentration · London
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
126
11-50
66
51-200
9
201-500
2
501-1,000
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 206 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 “third party security audit 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 629 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.

Third party security audit 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 “third party security audit companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many third party security audit companies are there based in the United Kingdom?

RevenueBase identified 206 company matches for third party security audit 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?

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

Which city has the most third party security audit companies?

London leads with 66 company records, followed by Manchester (8) and Cheltenham (5).

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 629 professional contacts with verified work emails tracked across these 206 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.