Company lists · Data verified August 2026

Top 25 Cybersecurity defense consultants based in the United Kingdom

Name: Cybersecurity defense consultants based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Verified Aug 28, 2026 1,647 companies tracked

There are 1,647 cybersecurity defense consultants headquartered in the United Kingdom (RevenueBase, August 2026). RevenueBase tracks 23,178 professional contacts across them, including 9,200 with verified work emails and 2,511 with mobile numbers. London is the largest hub.

This list covers cybersecurity defense consultants headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Data current as of August 28, 2026.

1,647Companies

23,178Contacts tracked

9,200Verified emails

2,511Mobile numbers

Unlock all 1,647 companies Free account · no credit card · 2 minutes

The 25 largest cybersecurity defense consultants based in the United Kingdom

Ranked by team size

Top 25 of 1,647 cybersecurity defense consultants based in the United Kingdom, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#	Company	HQ	Employees	Contacts	Verified emails
1	Sophos	Abingdon	5,001-10,000	4,963	2,711
2	Zerofox	n/a	501-1,000	894	382
3	SISA	Leicester	201-500	739	253
4	Everfox	London	1,001-5,000	635	13
5	MASS	Lincoln	201-500	633	203
6	Withsecure	London	501-1,000	614	329
7	Bridewell	Edinburgh	201-500	304	189
8	Quorum Cyber	Edinburgh	201-500	292	177
9	The Redesign Group	London	201-500	201	140
10	Fournet	Derby	201-500	173	115
11	Exclusive Networks UK	Mansfield	201-500	168	118
12	Cyberfort	Thatcham	51-200	160	88
13	LOGIQ	Bristol	201-500	142	81
14	Cybersec Consulting	London	201-500	141	76
15	CCL Solutions Group	Stratford Upon Avon	51-200	136	68
16	Cipher سايڤر	London	201-500	135	50
17	Trpglobal	London	51-200	123	36
18	Bulletproof Cyber Security	London	51-200	118	75
19	Caretower An Integrity360 Company	London	201-500	97	12
20	Cyberone	London	51-200	96	39
21	Softwerx	Cambridge	51-200	95	44
22	Wavenet Cyberguard	London	201-500	86	58
23	Cybersmart	London	51-200	83	55
24	Reliance Cyber	Waterloo	51-200	80	47
25	TDI Tetrad Digital Integrity	Windsor	51-200	71	39

Showing 25 of 1,647 cybersecurity defense consultants based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 9,200 reachable decision-makers.

Free account · no credit card

See all 1,647 companies

Cybersecurity defense consultants based in the United Kingdom at a glance

As of Aug 28, 2026

1-10Median size (employees)

LondonLargest hub · 662 HQs

2,511Contacts with mobile numbers

19Emails re-verified in last 30 days

Companies by employee count

1-10

1,051

11-50

427

51-200

115

201-500

501-1,000

1,001-5,000

5,001-10,000

Cybersecurity defense consultants by metro

Metro	Companies
Cybersecurity defense consultants in London	662
Cybersecurity defense consultants in Manchester	55
Cybersecurity defense consultants in Cheltenham	27
Cybersecurity defense consultants in Birmingham	26
Cybersecurity defense consultants in Cambridge	22
Cybersecurity defense consultants in Bristol	20
Cybersecurity defense consultants in Edinburgh	16

How this list was built

Source: The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion: Companies whose own business descriptions match “cybersecurity defense consultants”, with match quality audited by blind human judging, and headquartered in the United Kingdom.
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: Contact records re-verify on a rolling cadence; 19 contacts on this list were re-verified in the last 30 days.
Refresh: Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

How many cybersecurity defense consultants are there based in the United Kingdom?

There are 1,647 cybersecurity defense consultants headquartered in the United Kingdom as of August 2026 (RevenueBase).

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 defense consultants?

London leads with 662 headquartered companies, followed by Manchester (55) and Cheltenham (27).

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 9,200 verified decision-maker contacts tracked across these 1,647 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

Ready to reach these companies? Verified emails and direct dials for all 1,647 cybersecurity defense consultants based in the United Kingdom. Start with a free account, no credit card.

Get the full list

Related lists

Cybersecurity defense consultants by geography

Browse the directory

Browse: Companies home · All United Kingdom lists · All Cybersecurity defense consultants lists · New lists

About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.