Company lists · Data refreshed September 2026

Top 25 Network security monitoring services based in the United Kingdom

RevenueBase identified 360 network security monitoring services headquartered in the United Kingdom as of September 2026 and tracks 10,147 professional contacts across them, including 4,398 with verified work emails. London is the largest hub.

This list covers network security monitoring services 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 21, 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 21, 2026 86% judged on-target in blind review
360Companies
10,147Contacts tracked
4,398Verified emails
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The 25 largest network security monitoring services based in the United Kingdom

Ranked by team size
Top 25 of 360 network security monitoring services based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to network security monitoring services: 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 21, 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 21, 2026
2Partial evidenceLondon, United KingdomHQ checked Sep 21, 2026501-1,000502 contacts →

Partial evidence

SecurityHQ, a global cybersecurity company pioneering Security Performance Engineering for stronger operational performance and resilience.”

Source: RevenueBase Database · checked Sep 21, 2026
3Partial evidenceLondon, United KingdomHQ checked Sep 21, 2026201-500242 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
4Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-200177 contacts →

Indirect evidence

“Whether you’re a business or an individual, digital threats to your precious data and assets can come in any form - external or internal.”

Source: RevenueBase Database · checked Sep 21, 2026
5Partial evidenceThatcham, United KingdomHQ checked Sep 21, 202651-200159 contacts →

Partial evidence

“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…”

Source: RevenueBase Database · checked Sep 21, 2026
6Strong evidenceFleet, United KingdomHQ checked Sep 21, 202651-200125 contacts →

Strong evidence

“KHIPU Networks is an award winning international Cyber Security Company delivering a wide range of network, wireless and security solutions, technologies and services across…”

Source: RevenueBase Database · checked Sep 21, 2026
7Partial evidenceLeeds, United KingdomHQ checked Sep 21, 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 21, 2026
8Partial evidenceStourport-on-severn, United KingdomHQ checked Sep 21, 2026201-50086 contacts →

Partial evidence

“CyberGuard Technologies is the security division of Wavenet.”

Source: RevenueBase Database · checked Sep 21, 2026
9Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-20084 contacts →

Indirect evidence

“Cybersecurity should be simple.”

Source: RevenueBase Database · checked Sep 21, 2026
10Partial evidenceSwindon, United KingdomHQ checked Sep 21, 202651-20080 contacts →

Partial evidence

“When your business relies on security, compliance and a strong reputation for taking care of your customers, you need a partner that understands your ethos, your challenges and…”

Source: RevenueBase Database · checked Sep 21, 2026
11Indirect evidenceBournemouth, United KingdomHQ checked Sep 21, 202651-20066 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
12Strong evidenceIlkley, United KingdomHQ checked Sep 21, 202611-5062 contacts →

Strong evidence

“Talk Straight has been looking after the communications and network security for thousands of public and private sector organisations since 2007.”

Source: RevenueBase Database · checked Sep 21, 2026
13Partial evidenceAbingdon, United KingdomHQ checked Sep 21, 202651-20061 contacts →

Partial evidence

“e2e-assure is the UK's leading specialist in Managed Threat Detection and Response through our 24/7/365 UK owned and operated Security Operations Centre (SOC).”

Source: RevenueBase Database · checked Sep 21, 2026
14Strong evidenceOswestry, United KingdomHQ checked Sep 21, 202651-20054 contacts →

Strong evidence

“SNO is a specialist network operations and security partner, helping organisations design, secure, and manage the networks they rely on every day.”

Source: RevenueBase Database · checked Sep 21, 2026
15Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-20052 contacts →

Indirect evidence

“At Hexegic we are not just passionate about protecting data through our Cyber services we are passionate about helping companies release the potential of the data they hold…”

Source: RevenueBase Database · checked Sep 21, 2026
16Partial evidenceLondon, United KingdomHQ checked Sep 21, 202651-20051 contacts →

Partial evidence

“Redscan is an award-winning provider of managed security services, specialising in Managed Detection and Response, Penetration Testing and Red Teaming.”

Source: RevenueBase Database · checked Sep 21, 2026
17Indirect evidenceEdinburgh, United KingdomHQ checked Sep 21, 2026201-50051 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
18Partial evidenceLuton, United KingdomHQ checked Sep 21, 202651-20045 contacts →

Partial evidence

“Established in 2004 (acquired by Gamma in 2023), Satisnet, a Gamma company is a pedigree-proven cyber security services and solutions specialist with a fully UK-based 24x7x365 SOC.”

Source: RevenueBase Database · checked Sep 21, 2026
19Indirect evidenceBirmingham, United KingdomHQ checked Sep 21, 202651-20042 contacts →

Indirect evidence

“CyberQ Group is an award-winning, venture-backed, and globally accredited [ISO27K and CREST] cybersecurity leader dedicated to bridging the "protection gap" for high-stakes…”

Source: RevenueBase Database · checked Sep 21, 2026
20Partial evidenceCheltenham, United KingdomHQ checked Sep 21, 202651-20042 contacts →

Partial evidence

“CoreTech is a specialist cyber security company whose people are motivated by the desire to deliver exceptional capabilities coupled with a real sense of mission.”

Source: RevenueBase Database · checked Sep 21, 2026
21Partial evidencePortsmouth, United KingdomHQ checked Sep 21, 202651-20041 contacts →

Partial evidence

“We are on a mission to simplify and scale cyber security by combining AI, automation, expert-led services, in a unified platform: giving every organisation, from MSPs to global…”

Source: RevenueBase Database · checked Sep 21, 2026
22Indirect evidenceCirencester, United KingdomHQ checked Sep 21, 202611-5039 contacts →

Indirect evidence

“We help organisations understand, optimise, and strengthen their cybersecurity.”

Source: RevenueBase Database · checked Sep 21, 2026
23Strong evidenceCorsham, United KingdomHQ checked Sep 21, 202611-5039 contacts →

Strong evidence

“Computer Network Defence Ltd are a UK based cyber security consultancy with an extremely broad spectrum of capability.”

Source: RevenueBase Database · checked Sep 21, 2026
24Partial evidenceSaffron Walden, United KingdomHQ checked Sep 21, 202651-20038 contacts →

Partial evidence

“Omerta - A Global Security Technology and Services Company.”

Source: RevenueBase Database · checked Sep 21, 2026
25Indirect evidenceManchester, United KingdomHQ checked Sep 21, 202611-5036 contacts →

Indirect evidence

“Secarma exists to keep the world safe.”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 360 network security monitoring services based in the United Kingdom

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Network security monitoring services based in the United Kingdom at a glance

As of Sep 21, 2026
43.3%Verified-email coverage
28.2Average contacts per company
1-10Median size (employees)
37.8%Largest-city concentration · London
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
185
11-50
115
51-200
41
201-500
10
501-1,000
3
1,001-5,000
3
5,001-10,000
1
10001+
1

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 360 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 network security monitoring services, 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 “network security monitoring services”. 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 network security monitoring services), 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 network security monitoring services, 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, 4,398 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 21, 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.

Network security monitoring services by metro

  • Network security monitoring services in London136

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 network security monitoring services, 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 network security monitoring services are there based in the United Kingdom?

RevenueBase identified 360 network security monitoring services 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 network security monitoring services?

London leads with 136 headquartered companies, followed by Manchester (13) and Birmingham (10).

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 4,398 verified decision-maker contacts tracked across these 360 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 21, 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.