Company lists · Data refreshed November 2026

Top 21 Cybersecurity staffing based in the United Kingdom

Name: Cybersecurity staffing based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Nov 5, 2026 1,059 companies tracked

RevenueBase identified 1,059 company matches for cybersecurity staffing associated with the United Kingdom as of November 2026 and tracks 19,972 professional contacts across them, including 8,598 with verified work emails. London is the largest hub.

This list covers company matches for cybersecurity staffing 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

1,059Companies

19,972Contacts tracked

8,598Verified emails

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The 21 largest cybersecurity staffing based in the United Kingdom

Ranked by team size

Top 21 of 1,059 company matches for cybersecurity staffing 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.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	Sophos	Exact match	Abingdon, United KingdomHQ recorded Nov 5, 2026	5,001-10,000	5,283 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
2	Mimecast	Exact match	London, United KingdomHQ recorded Nov 5, 2026	1,001-5,000	2,389 contacts →
	Exact match “organizations.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
3	Bridewell	Exact match	Reading, United KingdomHQ recorded Nov 5, 2026	201-500	327 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
4	Quorum Cyber	Exact match	Edinburgh, United KingdomHQ recorded Nov 5, 2026	201-500	276 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
5	Security Blue Team	Exact match	London, United KingdomHQ recorded Nov 5, 2026	n/a	185 contacts →
	Exact match “Security Blue Team is now Centri.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
6	Exclusive Networks UK	Exact match	Alton, United KingdomHQ recorded Nov 5, 2026	201-500	181 contacts →
	Exact match “Exclusive Networks is a global trusted cybersecurity specialist for digital infrastructure helping to drive the transition to a totally trusted digital future for all people and…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
7	Cyberfort	Exact match	Thatcham, United KingdomHQ recorded Nov 5, 2026	51-200	161 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
8	Performanta	Exact match	Maidenhead, United KingdomHQ recorded Nov 5, 2026	51-200	157 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
9	SECON	Exact match	London, United KingdomHQ recorded Nov 5, 2026	11-50	127 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
10	Protection Group International	Exact match	London, United KingdomHQ recorded Nov 5, 2026	51-200	125 contacts →
	Exact match “PGI helps organisations build digital resilience.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
11	RED Sift	Exact match	London, United KingdomHQ recorded Nov 5, 2026	51-200	108 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
12	Conosco	Exact match	London, United KingdomHQ recorded Nov 5, 2026	51-200	105 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
13	Amethyst Risk Management	Exact match	Basingstoke, United KingdomHQ recorded Nov 5, 2026	11-50	91 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
14	Wavenet Cyberguard	Exact match	Stourport-on-severn, United KingdomHQ recorded Nov 5, 2026	201-500	90 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
15	Saepio Information Security	Exact match	High Wycombe, United KingdomHQ recorded Nov 5, 2026	51-200	86 contacts →
	Exact match “Saepio increase awareness, reduce risk and improve security in a continually evolving threat landscape.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
16	ITC Secure	Exact match	London, United KingdomHQ recorded Nov 5, 2026	51-200	86 contacts →
	Exact match “ITC Secure is an advisory-led cyber security services company.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
17	Sqep LTD	Exact match	Bristol, United KingdomHQ recorded Nov 5, 2026	51-200	85 contacts →
	Exact match “SQEP provides security-cleared experts across defence, aerospace and critical infrastructure.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
18	Reliance Cyber	Exact match	Waterloo, United KingdomHQ recorded Nov 5, 2026	51-200	84 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
19	White HAT An Epam Company	Exact match	London, United KingdomHQ recorded Nov 5, 2026	51-200	77 contacts →
	Exact match “White Hat, part of the EPAM group, is an award-winning cyber intelligence and offensive security company that leverages an attacker’s perspective to shape innovative, proactive…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
20	Dionach By Nomios	Exact match	Oxford, United KingdomHQ recorded Nov 5, 2026	51-200	76 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
21	Stripe OLT	Exact match	Bristol, United KingdomHQ recorded Nov 5, 2026	51-200	75 contacts →
	Exact match “From our offices in London, Bristol, and Manchester, Stripe OLT delivers cutting-edge cyber security and IT services to support and protect organisations in an ever-changing…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “cybersecurity staffing”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 21 of 1,059 cybersecurity staffing based in the United Kingdom

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Cybersecurity staffing based in the United Kingdom at a glance

As of Nov 5, 2026

43.1%Verified-email coverage

18.9Average contacts per company

1-10Median size (employees)

41.7%Largest-city concentration · London

Nov 5, 2026Page data refreshed

Companies by employee count

1-10

647

11-50

303

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

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 1,059 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 staffing” 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 8,598 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.

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

How many cybersecurity staffing are there based in the United Kingdom?

RevenueBase identified 1,059 company matches for cybersecurity staffing 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 staffing?

London leads with 442 company records, followed by Manchester (57) and Birmingham (26).

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 8,598 professional contacts with verified work emails tracked across these 1,059 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.