Company lists · Data refreshed September 2026

Top 25 Iso 27001 information security audit companies based in the United Kingdom

Name: Iso 27001 information security audit companies based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 278 companies tracked

RevenueBase identified 278 iso 27001 information security audit companies headquartered in the United Kingdom as of September 2026 and tracks 3,206 professional contacts across them, including 977 with verified work emails. London is the largest hub.

This list covers iso 27001 information security audit 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 28, 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 28, 2026 86% judged on-target in blind review

278Companies

3,206Contacts tracked

977Verified emails

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The 25 largest iso 27001 information security audit companies based in the United Kingdom

Ranked by team size

Top 25 of 278 iso 27001 information security audit companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to iso 27001 information security audit 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	COBRA	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	n/a	705 contacts →
	Partial evidence “Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.” Source: RevenueBase Database · checked Sep 28, 2026
2	operum.tech	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	n/a	186 contacts →
	Indirect evidence “IT support for businesses in London.” Source: RevenueBase Database · checked Sep 28, 2026
3	Amtivo Group	Partial evidence	West Malling, United KingdomHQ checked Sep 28, 2026	201-500	138 contacts →
	Partial evidence “Amtivo Group provides expert certification services for ISO standards, as well as training and related services.” Source: RevenueBase Database · checked Sep 28, 2026
4	Citation ISO Certification	Partial evidence	Norwich, United KingdomHQ checked Sep 28, 2026	51-200	115 contacts →
	Partial evidence “We believe in keeping ISO certification simple, so that's exactly what we do.” Source: RevenueBase Database · checked Sep 28, 2026
5	Isoqar	Indirect evidence	Manchester, United KingdomHQ checked Sep 28, 2026	51-200	99 contacts →
	Indirect evidence “Our reputation for providing outstanding service explains why clients who joined us when we first opened our doors in 1993 are still with us today.” Source: RevenueBase Database · checked Sep 28, 2026
6	IASME	Partial evidence	Upper Colwall, United KingdomHQ checked Sep 28, 2026	51-200	96 contacts →
	Partial evidence “IASME is a cyber security certification company based in the Malvern Hills, with an office in Belfast and one in Dalgety Bay, near Edinburgh.” Source: RevenueBase Database · checked Sep 28, 2026
7	URM	Strong evidence	Reading, United KingdomHQ checked Sep 28, 2026	51-200	81 contacts →
	Strong 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 28, 2026
8	NSI	Partial evidence	Maidenhead, United KingdomHQ checked Sep 28, 2026	51-200	72 contacts →
	Partial evidence “NSI is the UK’s most recognised certification body for fire and security.” Source: RevenueBase Database · checked Sep 28, 2026
9	Clear Quality Limited	Partial evidence	Rotherham, United KingdomHQ checked Sep 28, 2026	11-50	28 contacts →
	Partial evidence “Clear Quality is a professional ISO Consultancy business and Prime Training provider based in South Yorkshire.” Source: RevenueBase Database · checked Sep 28, 2026
10	Harptec LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	22 contacts →
	Partial evidence “We are a Cyber and Compliance focused Engineering company helping companies to achieve ISO standards and supporting the implementation of these standards through cutting-edge…” Source: RevenueBase Database · checked Sep 28, 2026
11	Advent IM	Strong evidence	Halesowen, United KingdomHQ checked Sep 28, 2026	11-50	21 contacts →
	Strong evidence “Advent IM is the UK’s leading independent GRC information and physical security consultancy and training provider.” Source: RevenueBase Database · checked Sep 28, 2026
12	Rightcue	Indirect evidence	Basingstoke, United KingdomHQ checked Sep 28, 2026	11-50	20 contacts →
	Indirect evidence “We help organisations achieve business-focused cybersecurity compliance across various industry and regulatory frameworks with successful stakeholder management, particularly in…” Source: RevenueBase Database · checked Sep 28, 2026
13	Bemcon	Partial evidence	Manchester, United KingdomHQ checked Sep 28, 2026	51-200	19 contacts →
	Partial evidence “Business Excellence & Management Consortium (BEMCON) is a professional training, consulting, and auditing organization specializing in ISO standards, occupational health & safety…” Source: RevenueBase Database · checked Sep 28, 2026
14	CQS Certified Quality Systems Limited	Partial evidence	Malvern, United KingdomHQ checked Sep 28, 2026	11-50	18 contacts →
	Partial evidence “CQS (Certified Quality Systems) Ltd delivers straightforward, practical ISO certification with over 25 years of experience.” Source: RevenueBase Database · checked Sep 28, 2026
15	CFE Certification	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	18 contacts →
	Strong evidence “We provide a wide range of auditing, certification and gap analysis services on; AI, DORA, NIS2, Information Security, Business Continuity, International IT Service, GDPR and…” Source: RevenueBase Database · checked Sep 28, 2026
16	Blackmores UK LTD	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	17 contacts →
	Partial evidence “ISO Standards can help you improve efficiency, reduce costs and increase tender opportunities.” Source: RevenueBase Database · checked Sep 28, 2026
17	Bruce & Butler	Partial evidence	Sheffield, United KingdomHQ checked Sep 28, 2026	11-50	15 contacts →
	Partial evidence “Bruce & Butler Limited are your partners in Data Protection & Cyber Security.” Source: RevenueBase Database · checked Sep 28, 2026
18	Forti5 Technologies	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	15 contacts →
	Indirect evidence “We help organisations keep their data safe, use technology responsibly, and stay on the right side of the law, without the jargon.” Source: RevenueBase Database · checked Sep 28, 2026
19	Glocert International	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	14 contacts →
	Indirect evidence “Glocert International is an emerging leader in the Testing, Inspection and Certification (TIC) industry.” Source: RevenueBase Database · checked Sep 28, 2026
20	Quadra LTD	Partial evidence	Holywood, United KingdomHQ checked Sep 28, 2026	11-50	13 contacts →
	Partial evidence “Quadra is a management systems consultancy and training organisation specialising in implementing management systems to international standards to include: Quality (ISO…” Source: RevenueBase Database · checked Sep 28, 2026
21	Secquest	Partial evidence	Southampton, United KingdomHQ checked Sep 28, 2026	11-50	12 contacts →
	Partial evidence “SecQuest offers specialised CHECK & CREST Cyber Security services to safeguard businesses against digital and physical threats.” Source: RevenueBase Database · checked Sep 28, 2026
22	Cyber Guarded LTD	Partial evidence	Belfast, United KingdomHQ checked Sep 28, 2026	11-50	12 contacts →
	Partial evidence “Cyber Guarded is a vendor independent business which provides Cyber Security auditing and testing services.” Source: RevenueBase Database · checked Sep 28, 2026
23	QCS International	Partial evidence	Cumbernauld, United KingdomHQ checked Sep 28, 2026	1-10	12 contacts →
	Partial evidence “QCS International are experts in ISO certification from management system implementation to auditor training.” Source: RevenueBase Database · checked Sep 28, 2026
24	NDC Certification Bureau LTD	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	12 contacts →
	Indirect evidence “NDC started 15 years ago as a consultancy firm; specialising in manufacturing, service and aerospace sectors.” Source: RevenueBase Database · checked Sep 28, 2026
25	Infosec Partners	Partial evidence	Winchester, United KingdomHQ checked Sep 28, 2026	11-50	12 contacts →
	Partial evidence “Security Consultants at Infosec Partners are formally trained to a high degree, having at least one of the following Security Management certifications: CESG CLAS, CISSP, CISM…” Source: RevenueBase Database · checked Sep 28, 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: iso 27001 information security audit companies. 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 iso 27001 information security audit companies.
Partial evidence: Its own public description names part of iso 27001 information security audit companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name iso 27001 information security audit companies. 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 278 iso 27001 information security audit companies based in the United Kingdom

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Iso 27001 information security audit companies based in the United Kingdom at a glance

As of Sep 28, 2026

30.5%Verified-email coverage

11.5Average contacts per company

1-10Median size (employees)

20.9%Largest-city concentration · London

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

205

11-50

51-200

201-500

501-1,000

5,001-10,000

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 278 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 iso 27001 information security audit 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 “iso 27001 information security audit 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 iso 27001 information security audit 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 iso 27001 information security audit 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, 977 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 28, 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.

Iso 27001 information security audit companies by metro

Iso 27001 information security audit companies in London58

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 iso 27001 information security audit 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 iso 27001 information security audit companies are there based in the United Kingdom?

RevenueBase identified 278 iso 27001 information security audit 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?

COBRA, headquartered in London, tops this list with the largest team on record.

Which city has the most iso 27001 information security audit companies?

London leads with 58 headquartered companies, followed by Manchester (10) and Birmingham (5).

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 977 verified decision-maker contacts tracked across these 278 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 28, 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.