Company lists · Data refreshed September 2026

Top 19 Security information and event management firms based in the United Kingdom

RevenueBase identified 43 security information and event management firms headquartered in the United Kingdom as of September 2026 and tracks 757 professional contacts across them, including 347 with verified work emails. London is the largest hub.

This list covers security information and event management firms 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
43Companies
757Contacts tracked
347Verified emails
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The 19 largest security information and event management firms based in the United Kingdom

Ranked by team size
Top 19 of 43 security information and event management firms 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 firms: 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
1Partial 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
2Partial 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
3Partial 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
4Partial evidenceNottingham, United KingdomHQ checked Sep 29, 202651-20059 contacts →

Partial evidence

“Nexor is a Secure Information Exchange Specialist offering High Assurance threat and risk mitigation expertise and solutions into complex and sensitive networks globally.”

Source: RevenueBase Database · checked Sep 29, 2026
5Indirect 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
6Partial 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
7Partial 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
8Partial evidenceWelwyn Garden City, United KingdomHQ checked Sep 29, 202651-20015 contacts →

Partial evidence

“Electronic Security Systems Design, Installation and Maintenance Provider.”

Source: RevenueBase Database · checked Sep 29, 2026
9Partial 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
10Partial evidenceLondon, United KingdomHQ checked Sep 29, 202611-507 contacts →

Partial evidence

“ISUMO leverage industry leading technologies to ensure optimum security, availability and compliance throughout your entire network.”

Source: RevenueBase Database · checked Sep 29, 2026
11Partial evidenceMilton Keynes, United KingdomHQ checked Sep 29, 20261-106 contacts →

Partial evidence

“Criticalis are network security specialists providing expertise through professional services and robust innovative managed services.”

Source: RevenueBase Database · checked Sep 29, 2026
12Partial evidenceBirmingham, United KingdomHQ checked Sep 29, 20261-106 contacts →

Partial evidence

“Tactile Technology is a leading provider of comprehensive physical and cyber security services.”

Source: RevenueBase Database · checked Sep 29, 2026
13Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261-105 contacts →

Indirect evidence

“Automate the boring.”

Source: RevenueBase Database · checked Sep 29, 2026
14Strong evidenceHove, United KingdomHQ checked Sep 29, 202611-505 contacts →

Strong evidence

“Locate-Global, a subsidiary of the Priavo Security Group, is a Global Incident Management platform designed to strengthen organisational resilience and enhance workforce safety…”

Source: RevenueBase Database · checked Sep 29, 2026
15Strong evidenceRichmond, United KingdomHQ checked Sep 29, 202651-2005 contacts →

Strong evidence

“Key Capabilities • 24/7 SIEM (Security Information and Event Management) • Virtual Helpdesk • SOC (Security Operations Center) • Robust Penetration Testing • Threat Intelligence…”

Source: RevenueBase Database · checked Sep 29, 2026
16Partial evidenceWinnersh Berkshire, United KingdomHQ checked Sep 29, 202651-2004 contacts →

Partial evidence

“Reliance High-Tech is a leading security integration services company with a client base of blue-chip companies across a variety of industry sectors.”

Source: RevenueBase Database · checked Sep 29, 2026
17Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202611-502 contacts →

Indirect evidence

“OwlGaze is the cybersecurity software company behind Blacklight AI SIEM.”

Source: RevenueBase Database · checked Sep 29, 2026
18Partial evidenceLondon, United KingdomHQ checked Sep 29, 20261-101 contacts →

Partial evidence

“At HOOP we have a deep understanding of all things Security Operations Defence.”

Source: RevenueBase Database · checked Sep 29, 2026
19Partial evidenceMaidstone, United KingdomHQ checked Sep 29, 20261-101 contacts →

Partial evidence

“Based in Maidstone, Kent, SAES was established in 2010 to provide advanced security and monitoring systems, combined with exceptional service to our clients.”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 19 of 43 security information and event management firms based in the United Kingdom

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

As of Sep 29, 2026
45.8%Verified-email coverage
17.6Average contacts per company
11-50Median size (employees)
41.9%Largest-city concentration · London
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
20
11-50
11
51-200
9
201-500
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 43 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 firms, 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 firms”. 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 firms), 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 firms, 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, 347 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.

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 firms, 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 firms are there based in the United Kingdom?

RevenueBase identified 43 security information and event management firms 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?

Obrela, headquartered in London, tops this list with the largest team on record.

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

London leads with 18 headquartered companies, followed by Birmingham (3) and Glasgow (2).

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 347 verified decision-maker contacts tracked across these 43 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.