Company lists · Data refreshed November 2026

Top 17 Cybersecurity startups based in the United Kingdom

RevenueBase identified 1,580 company matches for cybersecurity startups associated with the United Kingdom as of November 2026 and tracks 33,930 professional contacts across them, including 15,187 with verified work emails. London is the largest hub.

This list covers company matches for cybersecurity startups 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
1,580Companies
33,930Contacts tracked
15,187Verified emails
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The 17 largest cybersecurity startups based in the United Kingdom

Ranked by team size
Top 17 of 1,580 company matches for cybersecurity startups 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 matchCambridge, United KingdomHQ recorded Nov 5, 20261,001-5,0002,645 contacts →

Exact match

“Darktrace is a global leader in AI cybersecurity, providing the essential cybersecurity platform to secure organizations today and for an ever-changing future.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
3Exact matchLondon, United KingdomHQ recorded Nov 5, 20261,001-5,0002,389 contacts →

Exact match

“organizations.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
4Exact matchStaines-upon-thames, United KingdomHQ recorded Nov 5, 2026201-500811 contacts →

Exact match

“MTI provides award-winning, end-to-end technology solutions and services in cyber security and data centre for over 35 years.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
5Exact 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
6Exact 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
7Exact 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
8Exact 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
9Exact matchLondon, United KingdomHQ recorded Nov 5, 2026n/a185 contacts →

Exact match

“Security Blue Team is now Centri.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
10Exact matchAlton, United KingdomHQ recorded Nov 5, 2026201-500181 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
11Exact 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
12Exact 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
13Exact 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
14Exact 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
15Exact 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
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 matchCambridge, United KingdomHQ recorded Nov 5, 202651-200105 contacts →

Exact match

“For over 25 years, Cambridge-based Softwerx has redefined cybersecurity for midmarket organisations with its financially guaranteed 24×7x365 Managed XDR solutions.”

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

Showing 17 of 1,580 cybersecurity startups based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 15,187 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Cybersecurity startups based in the United Kingdom at a glance

As of Nov 5, 2026
44.8%Verified-email coverage
21.5Average contacts per company
1-10Median size (employees)
40.8%Largest-city concentration · London
Nov 5, 2026Page data refreshed

Companies by employee count

1-10
930
11-50
467
51-200
126
201-500
32
501-1,000
6
1,001-5,000
6
5,001-10,000
2
10001+
3

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 1,580 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 startups” 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 15,187 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 startups”; each Exact match badge shows search membership, not an individual similarity or quality score.

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

RevenueBase identified 1,580 company matches for cybersecurity startups 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 startups?

London leads with 645 company records, followed by Manchester (67) and Birmingham (31).

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 15,187 professional contacts with verified work emails tracked across these 1,580 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.