Company lists · Data verified August 2026

Top 25 Cybersecurity risk assessment firms based in the United Kingdom

Name: Cybersecurity risk assessment firms 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 1,196 companies tracked

There are 1,196 cybersecurity risk assessment firms headquartered in the United Kingdom (RevenueBase, August 2026). RevenueBase tracks 20,456 professional contacts across them, including 8,164 with verified work emails and 2,386 with mobile numbers. London is the largest hub.

This list covers cybersecurity risk assessment 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. Data current as of August 28, 2026.

1,196Companies

20,456Contacts tracked

8,164Verified emails

2,386Mobile numbers

Unlock all 1,196 companies Free account · no credit card · 2 minutes

The 25 largest cybersecurity risk assessment firms based in the United Kingdom

Ranked by team size

Top 25 of 1,196 cybersecurity risk assessment firms 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	Withsecure	London	501-1,000	614	329
6	Immersive	Bristol	201-500	360	183
7	Integrity360	London	501-1,000	341	199
8	Bridewell	Edinburgh	201-500	304	189
9	Risk Associates - Emea & Asia	London	51-200	169	62
10	Sapphire	Newcastle Upon Tyne	51-200	165	59
11	Cyberfort	Thatcham	51-200	160	88
12	Cybersec Consulting	London	201-500	141	76
13	Trpglobal	London	51-200	123	36
14	Thomas Murray	London	51-200	111	77
15	Panaseer	Godalming	51-200	101	63
16	Foresite Cybersecurity	Farnborough	51-200	100	67
17	Drawbridge	London	51-200	97	60
18	Cyberone	London	51-200	96	39
19	Wavenet Cyberguard	London	201-500	86	58
20	Reliance Cyber	Waterloo	51-200	80	47
21	URM	Reading	51-200	80	38
22	Izoologic	City Of London	201-500	67	48
23	Covertswarm	London	51-200	65	41
24	Cyro Cyber	London	51-200	63	10
25	Cybsafe	London	51-200	62	41

Showing 25 of 1,196 cybersecurity risk assessment firms based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 8,164 reachable decision-makers.

Free account · no credit card

See all 1,196 companies

Cybersecurity risk assessment firms based in the United Kingdom at a glance

As of Aug 28, 2026

1-10Median size (employees)

LondonLargest hub · 522 HQs

2,386Contacts with mobile numbers

15Emails re-verified in last 30 days

Companies by employee count

1-10

731

11-50

334

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

Cybersecurity risk assessment firms by metro

Metro	Companies
Cybersecurity risk assessment firms in London	522
Cybersecurity risk assessment firms in Manchester	45
Cybersecurity risk assessment firms in Birmingham	24
Cybersecurity risk assessment firms in Cheltenham	23
Cybersecurity risk assessment firms in Cambridge	17
Cybersecurity risk assessment firms in Bristol	14
Cybersecurity risk assessment firms in Leeds	12

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 risk assessment firms”, 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; 15 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 risk assessment firms are there based in the United Kingdom?

There are 1,196 cybersecurity risk assessment firms 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 risk assessment firms?

London leads with 522 headquartered companies, followed by Manchester (45) and Birmingham (24).

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 8,164 verified decision-maker contacts tracked across these 1,196 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 1,196 cybersecurity risk assessment firms based in the United Kingdom. Start with a free account, no credit card.

Get the full list

Related lists

Cybersecurity risk assessment firms by geography

Browse the directory

Browse: Companies home · All United Kingdom lists · All Cybersecurity risk assessment firms 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.