Company lists · Data refreshed September 2026

Top 25 Cybersecurity incident response firms based in the United Kingdom

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

Compiled by the RevenueBase Data Team Data refreshed Sep 1, 2026 706 companies tracked

RevenueBase identified 706 cybersecurity incident response firms headquartered in the United Kingdom as of September 2026 and tracks 14,396 professional contacts across them, including 5,824 with verified work emails and 1,737 with mobile numbers. London is the largest hub.

This list covers cybersecurity incident response 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 1, 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 RevenueBase Smart Search rating on every row Refreshed Sep 1, 2026 86% judged on-target in blind review

706Companies

14,396Contacts tracked

5,824Verified emails

1,737Mobile numbers

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The 25 largest cybersecurity incident response firms based in the United Kingdom

Ranked by team size

Top 25 of 706 cybersecurity incident response firms based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 1, 2026. RevenueBase Smart Search rates how each company's information relates to cybersecurity incident response 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	SISA	Partial evidence	Leicester, United Kingdom	201-500	739 contacts →
	Partial evidence “SISA is a global forensics-driven cybersecurity solutions company, trusted by leading organizations for securing their businesses with robust preventive, detective, and corrective…” Source: RevenueBase Database · checked Sep 1, 2026
2	Everfox	Indirect evidence	London, United Kingdom	1,001-5,000	635 contacts →
	Indirect evidence “Everfox delivers trusted connectivity to protect the world's most critical environments, safeguarding the sensitive information behind decision advantage.” Source: RevenueBase Database · checked Sep 1, 2026
3	Withsecure	Partial evidence	London, United Kingdom	501-1,000	614 contacts →
	Partial evidence “WithSecure™ is Europe's cybersecurity partner of choice.” Source: RevenueBase Database · checked Sep 1, 2026
4	Bridewell	Indirect evidence	Edinburgh, United Kingdom	201-500	304 contacts →
	Indirect evidence “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…” Source: RevenueBase Database · checked Sep 1, 2026
5	Cyberfort	Indirect evidence	Thatcham, United Kingdom	51-200	160 contacts →
	Indirect 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 1, 2026
6	Cybersec Consulting	Indirect evidence	London, United Kingdom	201-500	141 contacts →
	Indirect evidence “CyberSec Consulting, headquartered in the UAE and serving the iMETA market, is a distinguished professional Cyber Security and Consulting services company.” Source: RevenueBase Database · checked Sep 1, 2026
7	CCL Solutions Group	Indirect evidence	Stratford Upon Avon, United Kingdom	51-200	136 contacts →
	Indirect evidence “CCL Solutions Group is one of Europe’s leading digital forensics, digital investigation and cyber security specialists, supporting law enforcement, government agencies, military…” Source: RevenueBase Database · checked Sep 1, 2026
8	Khipu Networks	Indirect evidence	Fleet, United Kingdom	51-200	129 contacts →
	Indirect 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 1, 2026
9	Bulletproof Cyber Security	Indirect evidence	London, United Kingdom	51-200	118 contacts →
	Indirect evidence “Bulletproof is now part of WorkNest Secure.” Source: RevenueBase Database · checked Sep 1, 2026
10	Sep2	Indirect evidence	London, United Kingdom	51-200	99 contacts →
	Indirect 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 1, 2026
11	Cyberone	Indirect evidence	London, United Kingdom	51-200	96 contacts →
	Indirect evidence “CyberOne is a Microsoft Security Elite Partner and one of only 100 global Microsoft partners recognised with Microsoft-Verified Managed XDR solution status.” Source: RevenueBase Database · checked Sep 1, 2026
12	Softwerx	Partial evidence	Cambridge, United Kingdom	51-200	95 contacts →
	Partial evidence “For over 25 years, Cambridge-based Softwerx has redefined cybersecurity for midmarket organisations with its financially guaranteed 24×7x365 Managed XDR solutions.” Source: RevenueBase Database · checked Sep 1, 2026
13	ITC Secure	Indirect evidence	London, United Kingdom	51-200	87 contacts →
	Indirect evidence “ITC Secure is an advisory-led cyber security services company.” Source: RevenueBase Database · checked Sep 1, 2026
14	Wavenet Cyberguard	Indirect evidence	London, United Kingdom	201-500	86 contacts →
	Indirect evidence “CyberGuard Technologies is the security division of Wavenet.” Source: RevenueBase Database · checked Sep 1, 2026
15	Cybersmart	Partial evidence	London, United Kingdom	51-200	83 contacts →
	Partial evidence “Cybersecurity should be simple.” Source: RevenueBase Database · checked Sep 1, 2026
16	Reliance Cyber	Indirect evidence	Waterloo, United Kingdom	51-200	80 contacts →
	Indirect evidence “At Reliance Cyber, we believe in truly partnering with our customers.” Source: RevenueBase Database · checked Sep 1, 2026
17	Saepio Information Security	Indirect evidence	High Wycombe, United Kingdom	51-200	73 contacts →
	Indirect evidence “Saepio increase awareness, reduce risk and improve security in a continually evolving threat landscape.” Source: RevenueBase Database · checked Sep 1, 2026
18	Izoologic	Strong evidence	City Of London, United Kingdom	201-500	67 contacts →
	Strong evidence “Protecting the world’s leading Enterprise and Government organisations iZOOlogic provides bespoke and curated Threat Intelligence and Incident Response Asset Discovery and…” Source: RevenueBase Database · checked Sep 1, 2026
19	Cyro Cyber	Indirect evidence	London, United Kingdom	51-200	63 contacts →
	Indirect evidence “Cyro Cyber are your cyber security Guardians.” Source: RevenueBase Database · checked Sep 1, 2026
20	Daintta	Indirect evidence	London, United Kingdom	51-200	61 contacts →
	Indirect evidence “We provide deep expertise with technical and business specialists to help clients secure and protect the UK.” Source: RevenueBase Database · checked Sep 1, 2026
21	Digitalxraid	Indirect evidence	Doncaster, United Kingdom	51-200	59 contacts →
	Indirect evidence “At DigitalXRAID, we’re more than just a managed security services provider – we’re your trusted partner in safeguarding your business from cyber threats.” Source: RevenueBase Database · checked Sep 1, 2026
22	Cyberlab	Indirect evidence	Lincoln, United Kingdom	51-200	56 contacts →
	Indirect evidence “CyberLab is the UK-leading cyber security consultancy and managed services provider, trusted by over 1,200 enterprise businesses, government departments, and household names to…” Source: RevenueBase Database · checked Sep 1, 2026
23	Istari	Partial evidence	London, United Kingdom	51-200	53 contacts →
	Partial evidence “ISTARI is a global cybersecurity firm, established by Temasek in 2020, with a unique model for helping clients build cyber resilience.” Source: RevenueBase Database · checked Sep 1, 2026
24	Hexegic	Indirect evidence	London, United Kingdom	51-200	52 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 1, 2026
25	Redscan, A Kroll Business	Partial evidence	London, United Kingdom	51-200	52 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 1, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: cybersecurity incident response firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names cybersecurity incident response firms.
Partial evidence: Its own public description names part of cybersecurity incident response firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name cybersecurity incident response firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 706 cybersecurity incident response firms based in the United Kingdom

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Cybersecurity incident response firms based in the United Kingdom at a glance

As of Sep 1, 2026

40.5%Verified-email coverage

12.1%Mobile-number coverage

20.4Average contacts per company

1-10Median size (employees)

43.3%Largest-city concentration · London

Sep 1, 2026Page data refreshed

Companies by employee count

1-10

405

11-50

210

51-200

201-500

501-1,000

1,001-5,000

10001+

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 cybersecurity incident response 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 “cybersecurity incident response 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 cybersecurity incident response 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 cybersecurity incident response 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, 5,824 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 1, 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.

Cybersecurity incident response firms by metro

Cybersecurity incident response firms in London306
Cybersecurity incident response firms in Manchester29

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 cybersecurity incident response 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 cybersecurity incident response firms are there based in the United Kingdom?

RevenueBase identified 706 cybersecurity incident response 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?

SISA, headquartered in Leicester, tops this list with the largest team on record.

Which city has the most cybersecurity incident response firms?

London leads with 306 headquartered companies, followed by Manchester (29) and Cheltenham (17).

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 5,824 verified decision-maker contacts tracked across these 706 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 1, 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.