Company lists · Data refreshed September 2026

Top 25 Security information and event management startups based in the United Kingdom

RevenueBase identified 121 security information and event management startups headquartered in the United Kingdom as of September 2026 and tracks 6,824 professional contacts across them, including 3,450 with verified work emails. London is the largest hub.

This list covers security information and event management startups headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 29, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, 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 HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 29, 2026 86% judged on-target in blind review
121Companies
6,824Contacts tracked
3,450Verified emails
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The 25 largest security information and event management startups based in the United Kingdom

Ranked by team size
Top 25 of 121 security information and event management startups based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to security information and event management startups: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceAbingdon, United KingdomHQ checked Sep 29, 20265,001-10,0004,925 contacts →

Indirect evidence

“Sophos is a cybersecurity leader defending organizations globally with an AI-driven platform and expert-led services.”

Source: RevenueBase Database · checked Sep 29, 2026
2Indirect evidenceEdinburgh, United KingdomHQ checked Sep 29, 2026201-500297 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 29, 2026
3Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500242 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 29, 2026
4Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202651-200109 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 29, 2026
5Partial evidenceLeeds, United KingdomHQ checked Sep 29, 202651-20095 contacts →

Partial evidence

“SEP2 is an award-winning UK-based cyber security specialist service provider, powered by a dedicated team of experts available 24/7/365.”

Source: RevenueBase Database · checked Sep 29, 2026
6Partial evidenceLondon, United KingdomHQ checked Sep 29, 202651-20079 contacts →

Partial evidence

“Cybanetix is a leading provider of managed Cyber Security Service and hosted SIEM and breach detection services.”

Source: RevenueBase Database · checked Sep 29, 2026
7Indirect evidenceBlandford, United KingdomHQ checked Sep 29, 202651-20068 contacts →

Indirect evidence

“The organisations that run our world face relentless complexity and evolving threats.”

Source: RevenueBase Database · checked Sep 29, 2026
8Indirect evidenceBournemouth, United KingdomHQ checked Sep 29, 202651-20066 contacts →

Indirect evidence

“We help businesses and individuals stay protected in an increasingly complex digital world.”

Source: RevenueBase Database · checked Sep 29, 2026
9Strong evidenceLondon, United KingdomHQ checked Sep 29, 202651-20061 contacts →

Strong evidence

“Intruder's continuous exposure management platform helps security, IT, and engineering teams stop breaches before they start.”

Source: RevenueBase Database · checked Sep 29, 2026
10Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202651-20054 contacts →

Indirect evidence

“SenseOn deploys alongside all of your existing tools, unifying them into a single investigation plane and augmenting your team with cross-domain correlation, analytics, and…”

Source: RevenueBase Database · checked Sep 29, 2026
11Indirect evidenceEdinburgh, United KingdomHQ checked Sep 29, 2026201-50051 contacts →

Indirect evidence

“We are Adarma, independent leaders in detection and response services.”

Source: RevenueBase Database · checked Sep 29, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5036 contacts →

Partial evidence

“The future of IoT/OT security is here.”

Source: RevenueBase Database · checked Sep 29, 2026
13Partial evidenceStevenage, United KingdomHQ checked Sep 29, 202651-20032 contacts →

Partial evidence

“Defense.com is transforming the way businesses manage cyber security by allowing them to easily identify, prioritise and remediate threats.”

Source: RevenueBase Database · checked Sep 29, 2026
14Partial evidencePeterborough, United KingdomHQ checked Sep 29, 202651-20032 contacts →

Partial evidence

“Intrinsic Security is a UK-headquartered cybersecurity firm delivering 24/7 threat detection, incident response, and resilience across cloud, hybrid, OT, IoT, and identity…”

Source: RevenueBase Database · checked Sep 29, 2026
15Partial evidenceLondon, United KingdomHQ checked Sep 29, 202651-20024 contacts →

Partial evidence

“Nanjgel Solutions is focused on delivering the best IT security for businesses.”

Source: RevenueBase Database · checked Sep 29, 2026
16Partial evidenceFarnborough, United KingdomHQ checked Sep 29, 202611-5022 contacts →

Partial evidence

“BlueFort is the UK’s leading independent Security Solutions Partner (SSP).”

Source: RevenueBase Database · checked Sep 29, 2026
17Partial evidenceBristol, United KingdomHQ checked Sep 29, 202611-5017 contacts →

Partial evidence

“We help organisations turn security, operations and log data into actionable intelligence - so monitoring platforms deliver real outcomes, not just dashboards.”

Source: RevenueBase Database · checked Sep 29, 2026
18Strong evidenceWimbledon, United KingdomHQ checked Sep 29, 202651-20017 contacts →

Strong evidence

“Policy Monitor provides security policy management solutions and services to measure, manage and monitor cyber risk, and guard against cyber-attacks.”

Source: RevenueBase Database · checked Sep 29, 2026
19Indirect evidenceNewbury, United KingdomHQ checked Sep 29, 202611-5016 contacts →

Indirect evidence

“CyberHive protects the most valued organisations, their people data, and assets, with patented technology that is simple, secure and performant.”

Source: RevenueBase Database · checked Sep 29, 2026
20Partial evidenceReading, United KingdomHQ checked Sep 29, 202611-5013 contacts →

Partial evidence

“Assuria provides trusted cyber security software solutions and managed security services that power Security Operations Centres, IT Protective Monitoring services and IT Assurance…”

Source: RevenueBase Database · checked Sep 29, 2026
21Indirect evidenceCardiff, United KingdomHQ checked Sep 29, 202611-5011 contacts →

Indirect evidence

“Pervade Software is the UK-based creator of OpView™, OpAudit™ and OpIndex™.”

Source: RevenueBase Database · checked Sep 29, 2026
22Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5010 contacts →

Partial evidence

“PC POWER INTERNATIONAL LTD is a computer & network security company based in the City, London, United Kingdom.”

Source: RevenueBase Database · checked Sep 29, 2026
23Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-5010 contacts →

Partial evidence

“Defenx is an IT company that has an extensive background in providing businesses with cloud based security solutions and support for their digital infrastructure.”

Source: RevenueBase Database · checked Sep 29, 2026
24Partial evidenceMilton Keynes, United KingdomHQ checked Sep 29, 202611-509 contacts →

Partial evidence

“DefensityOne is a cybersecurity solutions provider specializing in proactive threat detection, risk management, and digital defense services.”

Source: RevenueBase Database · checked Sep 29, 2026
25Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-508 contacts →

Partial evidence

“Cyberseer offers Advanced Threat Detection and a 24×7 Managed Security Service (MSS).”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 121 security information and event management startups based in the United Kingdom

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Security information and event management startups based in the United Kingdom at a glance

As of Sep 29, 2026
50.6%Verified-email coverage
56.4Average contacts per company
11-50Median size (employees)
43.0%Largest-city concentration · London
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
54
11-50
39
51-200
16
201-500
6
501-1,000
2
5,001-10,000
1
10001+
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 121 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among security information and event management startups, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United Kingdom whose own description of what they do matches “security information and event management startups”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names security information and event management startups), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among security information and event management startups, and records with no verified work email. Companies headquartered outside United Kingdom are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
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 listed company carries at least one verified work email, 3,450 across the full list. 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.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Security information and event management startups by metro

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names security information and event management startups, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many security information and event management startups are there based in the United Kingdom?

RevenueBase identified 121 security information and event management startups headquartered in the United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Sophos, headquartered in Abingdon, tops this list with the largest team on record.

Which city has the most security information and event management startups?

London leads with 52 headquartered companies, followed by Manchester (6) and Glasgow (3).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 3,450 verified decision-maker contacts tracked across these 121 companies.

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 Smart Search, 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.