Company lists · Data refreshed September 2026

Top 25 Cybersecurity consulting companies based in the United Kingdom

RevenueBase identified 1,836 cybersecurity consulting companies headquartered in the United Kingdom as of September 2026 and tracks 22,779 professional contacts across them, including 9,034 with verified work emails and 2,386 with mobile numbers. London is the largest hub.

This list covers cybersecurity consulting companies 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
1,836Companies
22,779Contacts tracked
9,034Verified emails
2,386Mobile numbers
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The 25 largest cybersecurity consulting companies based in the United Kingdom

Ranked by team size
Top 25 of 1,836 cybersecurity consulting companies 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 consulting companies: 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 evidenceAbingdon, United Kingdom5,001-10,0004,963 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 1, 2026
2Partial evidenceLeicester, United Kingdom201-500739 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
3Indirect evidenceLondon, United Kingdom1,001-5,000635 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
4Partial evidenceLondon, United Kingdom501-1,000614 contacts →

Partial evidence

“WithSecure™ is Europe's cybersecurity partner of choice.”

Source: RevenueBase Database · checked Sep 1, 2026
5Indirect evidenceEdinburgh, United Kingdom201-500304 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
6Indirect evidenceEdinburgh, United Kingdom201-500292 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 1, 2026
7Strong evidenceLondon, United Kingdom201-500201 contacts →

Strong evidence

“The Redesign Group is a global technology and cybersecurity consulting firm leveraging design thinking, interdependent subject matter expertise, and emerging technology solutions…”

Source: RevenueBase Database · checked Sep 1, 2026
8Indirect evidenceLondon, United Kingdom201-500188 contacts →

Indirect evidence

“Intragen is a cyber security business focused on managed Identity solutions and services.”

Source: RevenueBase Database · checked Sep 1, 2026
9Partial evidenceMansfield, United Kingdom201-500168 contacts →

Partial evidence

“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…”

Source: RevenueBase Database · checked Sep 1, 2026
10Indirect evidenceThatcham, United Kingdom51-200160 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
11Indirect evidenceBristol, United Kingdom201-500142 contacts →

Indirect evidence

“Logiq is a UK-based cyber security consultancy and secure managed services provider supporting defence, government, and critical national infrastructure (CNI) organisations where…”

Source: RevenueBase Database · checked Sep 1, 2026
12Partial evidenceLondon, United Kingdom201-500141 contacts →

Partial 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
13Indirect evidenceStratford Upon Avon, United Kingdom51-200136 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
14Partial evidenceLondon, United Kingdom201-500135 contacts →

Partial evidence

“At Cipher, we're redefining digital security as the premier cybersecurity leader in the Middle East.”

Source: RevenueBase Database · checked Sep 1, 2026
15Indirect evidenceLondon, United Kingdom51-200123 contacts →

Indirect evidence

“We are TRPGLOBAL, your strategic partner in helping you with the complexities of risk management.”

Source: RevenueBase Database · checked Sep 1, 2026
16Partial evidenceLondon, United Kingdom501-1,000120 contacts →

Partial evidence

“Integrity360 is a leading independent cybersecurity and PCI specialist operating across EMEA and North America, with offices spanning the UK and Ireland, Bulgaria, Italy, Sweden…”

Source: RevenueBase Database · checked Sep 1, 2026
17Indirect evidenceLondon, United Kingdom51-200118 contacts →

Indirect evidence

“Bulletproof is now part of WorkNest Secure.”

Source: RevenueBase Database · checked Sep 1, 2026
18Indirect evidenceLondon, United Kingdom51-20099 contacts →

Indirect evidence

“OryxAlign creates true alignment that delivers the right outcomes for all.”

Source: RevenueBase Database · checked Sep 1, 2026
19Indirect evidenceLondon, United Kingdom51-20096 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
20Indirect evidenceLondon, United Kingdom201-50086 contacts →

Indirect evidence

“CyberGuard Technologies is the security division of Wavenet.”

Source: RevenueBase Database · checked Sep 1, 2026
21Partial evidenceLondon, United Kingdom51-20083 contacts →

Partial evidence

Cybersecurity should be simple.”

Source: RevenueBase Database · checked Sep 1, 2026
22Indirect evidenceWaterloo, United Kingdom51-20080 contacts →

Indirect evidence

“At Reliance Cyber, we believe in truly partnering with our customers.”

Source: RevenueBase Database · checked Sep 1, 2026
23Partial evidenceReading, United Kingdom51-20080 contacts →

Partial evidence

“Established in 2005, URM Consulting is a specialist provider of cyber and information security consultancy, training, and assurance services.”

Source: RevenueBase Database · checked Sep 1, 2026
24Indirect evidenceMilton Keynes, United Kingdom201-50073 contacts →

Indirect evidence

“Bluecube - An Ekco Company Our mission is simple.”

Source: RevenueBase Database · checked Sep 1, 2026
25Partial evidenceWindsor, United Kingdom51-20071 contacts →

Partial evidence

“For over 20 years, TDI’s one and only passion has been delivering cybersecurity solutions to effectively manage the business of cyber.”

Source: RevenueBase Database · checked Sep 1, 2026

Showing 25 of 1,836 cybersecurity consulting companies based in the United Kingdom

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Cybersecurity consulting companies based in the United Kingdom at a glance

As of Sep 1, 2026
39.7%Verified-email coverage
10.5%Mobile-number coverage
12.4Average contacts per company
1-10Median size (employees)
39.4%Largest-city concentration · London
Sep 1, 2026Page data refreshed

Companies by employee count

1-10
1,180
11-50
472
51-200
122
201-500
28
501-1,000
8
1,001-5,000
5
5,001-10,000
2

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 consulting companies, 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 consulting companies”. 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 consulting companies), 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 consulting companies, 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, 9,034 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.

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 consulting companies, 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 consulting companies are there based in the United Kingdom?

RevenueBase identified 1,836 cybersecurity consulting companies 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 cybersecurity consulting companies?

London leads with 724 headquartered companies, followed by Manchester (61) and Birmingham (32).

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 9,034 verified decision-maker contacts tracked across these 1,836 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.