Company lists · Data refreshed November 2026

Top 19 Cybersecurity assessment services based in the United Kingdom

RevenueBase identified 1,432 company matches for cybersecurity assessment services associated with the United Kingdom as of November 2026 and tracks 21,151 professional contacts across them, including 8,663 with verified work emails. London is the largest hub.

This list covers company matches for cybersecurity 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
1,432Companies
21,151Contacts tracked
8,663Verified emails
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The 19 largest cybersecurity assessment services based in the United Kingdom

Ranked by team size
Top 19 of 1,432 company matches for cybersecurity 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 matchAbingdon, United KingdomHQ recorded Nov 5, 20265,001-10,0005,283 contacts →

Exact match

“Sophos, a global cybersecurity leader, defends more than organizations worldwide with Sophos Fusion, the industry's first and most complete AI-native cybersecurity defense system…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
2Exact 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
3Exact matchLondon, United KingdomHQ recorded Nov 5, 2026501-1,000426 contacts →

Exact match

“At Resillion, we're more than just a global leader in quality engineering, testing, and cyber security – we're your dedicated partner from the start of your project to its…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
4Exact matchReading, United KingdomHQ recorded Nov 5, 2026201-500327 contacts →

Exact match

“Bridewell is the trusted cyber security partner for organisations operating within Critical National Infrastructure (CNI), as well as companies who want the highest standard of…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
5Exact matchEdinburgh, United KingdomHQ recorded Nov 5, 2026201-500276 contacts →

Exact match

“At Quorum Cyber, we're on a mission to help good people win.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
6Exact matchLeeds, United KingdomHQ recorded Nov 5, 2026201-500257 contacts →

Exact match

“We are a global boutique, specializing exclusively in the convergence of identity-driven security and networking.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
7Exact matchNewcastle Upon Tyne, United KingdomHQ recorded Nov 5, 202651-200187 contacts →

Exact match

“Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
8Exact matchManchester, United KingdomHQ recorded Nov 5, 2026201-500166 contacts →

Exact match

“FourNet transforms the customer and citizen services people rely on every day.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
9Exact matchBradley Stoke, United KingdomHQ recorded Nov 5, 2026201-500164 contacts →

Exact match

“Logiq is a UK-based cyber security consultancy and secure managed services provider supporting defence, government, and critical national infrastructure (CNI) organisations where…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
10Exact matchThatcham, United KingdomHQ recorded Nov 5, 202651-200161 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 · Nov 5, 2026 · View company records in RevenueBase
11Exact matchMaidenhead, United KingdomHQ recorded Nov 5, 202651-200157 contacts →

Exact match

“Performanta is a global cybersecurity and data risk management company dedicated to protecting people where data matters most.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
12Exact matchLondon, United KingdomHQ recorded Nov 5, 202611-50127 contacts →

Exact match

“At Secon, we empower our clients to reach their full potential by taking the stress out of cyber security.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
13Exact matchLondon, United KingdomHQ recorded Nov 5, 202651-200108 contacts →

Exact match

“Red Sift enables organizations to anticipate, respond to, and recover from cyber attacks while continuing to operate effectively.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
14Exact matchLondon, United KingdomHQ recorded Nov 5, 202651-200108 contacts →

Exact match

“CyberOne is a Microsoft Security Elite Partner and one of only 100 global Microsoft partners recognised with Microsoft-Verified Managed XDR solution status.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
15Exact matchLeeds, United KingdomHQ recorded Nov 5, 202651-200106 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 · Nov 5, 2026 · View company records in RevenueBase
16Exact matchLondon, United KingdomHQ recorded Nov 5, 202651-200105 contacts →

Exact match

“Cybersecurity specialists providing technology and telecoms solutions that gives you the leadership, experience and resilience you need to build and secure the future of work.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
17Exact matchLondon, United KingdomHQ recorded Nov 5, 202651-20096 contacts →

Exact match

“Dedicated to securing the networks society depends on.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
18Exact matchBasingstoke, United KingdomHQ recorded Nov 5, 202611-5091 contacts →

Exact match

“Amethyst Risk Management is a leading cybersecurity consultancy supplying expert services and support to the UK Government, Defence, Operators of Essential Services, and the…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
19Exact matchStourport-on-severn, United KingdomHQ recorded Nov 5, 2026201-50090 contacts →

Exact match

“CyberGuard Technologies is the security division of Wavenet.”

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

Showing 19 of 1,432 cybersecurity assessment services based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 8,663 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Cybersecurity assessment services based in the United Kingdom at a glance

As of Nov 5, 2026
41.0%Verified-email coverage
14.8Average contacts per company
1-10Median size (employees)
39.8%Largest-city concentration · London
Nov 5, 2026Page data refreshed

Companies by employee count

1-10
912
11-50
376
51-200
102
201-500
25
501-1,000
6
1,001-5,000
4
5,001-10,000
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 1,432 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 “cybersecurity 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 8,663 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.

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

How many cybersecurity assessment services are there based in the United Kingdom?

RevenueBase identified 1,432 company matches for cybersecurity 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?

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

Which city has the most cybersecurity assessment services?

London leads with 570 company records, followed by Manchester (61) and Birmingham (30).

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 8,663 professional contacts with verified work emails tracked across these 1,432 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.