Company lists · Data refreshed September 2026

Top 25 Cybersecurity audit firms worldwide

RevenueBase identified 13,905 cybersecurity audit firms worldwide as of September 2026 and tracks 161,411 professional contacts across them, including 44,473 with verified work emails. The United States is the largest market and London the largest hub.

This list covers cybersecurity audit firms worldwide, 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 21, 2026. Country and city lists for cybersecurity audit firms follow the table.

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 21, 2026 86% judged on-target in blind review
13,905Companies
161,411Contacts tracked
44,473Verified emails
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The 25 largest cybersecurity audit firms worldwide

Ranked by team size
Top 25 of 13,905 cybersecurity audit firms worldwide, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to cybersecurity audit 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceUnited StatesHQ checked Sep 21, 2026n/a12,771 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 21, 2026
2Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 21, 2026n/a3,649 contacts →

Indirect evidence

“We are a crowdsourced security company that safeguards organizations' assets from sophisticated threat actors before they can strike-by uniting our customers with trusted hackers…”

Source: RevenueBase Database · checked Sep 21, 2026
3Indirect evidenceLeawood, KS, United StatesHQ checked Sep 21, 20261,001-5,0002,222 contacts →

Indirect evidence

“Optiv is the cyber advisory and solutions leader, delivering strategic and technical expertise to nearly companies across every major industry.”

Source: RevenueBase Database · checked Sep 21, 2026
4Indirect evidenceAl Nakheel, Saudi ArabiaHQ checked Sep 21, 2026501-1,0001,378 contacts →

Indirect evidence

“We are established for enriching local content in designing, developing, and operating secure digital computing environments through Saudi talents, by fulfilling our role as a…”

Source: RevenueBase Database · checked Sep 21, 2026
5Partial evidenceAustin, TX, United StatesHQ checked Sep 21, 20261,001-5,0001,252 contacts →

Partial evidence

“Thales is a global leader in cybersecurity, helping the most trusted organizations in the world protect their most critical applications, data, and identities anywhere at scale.”

Source: RevenueBase Database · checked Sep 21, 2026
6Partial evidenceReston, VA, United StatesHQ checked Sep 21, 20261,001-5,0001,232 contacts →

Partial evidence

“GuidePoint Security provides trusted cybersecurity expertise, solutions, and services that help organizations make informed decisions and minimize risk.”

Source: RevenueBase Database · checked Sep 21, 2026
7Partial evidenceHoofddorp, NetherlandsHQ checked Sep 21, 20261,001-5,0001,026 contacts →

Partial evidence

“Irdeto, a CANAL+ company, is the world leader in digital platform cybersecurity, empowering businesses to innovate for a secure, connected future.”

Source: RevenueBase Database · checked Sep 21, 2026
8Partial evidenceChicago, IL, United StatesHQ checked Sep 21, 20261,001-5,000947 contacts →

Partial evidence

“Coalfire is the premier Cybersecurity and Compliance Services leader for the tech, healthcare, and finance industries.(This page is maintained by Marketing.”

Source: RevenueBase Database · checked Sep 21, 2026
9Partial evidenceSingaporeHQ checked Sep 21, 2026501-1,000888 contacts →

Partial evidence

“Ensign InfoSecurity is the largest pure-play end-to-end cybersecurity service provider in Asia.”

Source: RevenueBase Database · checked Sep 21, 2026
10Partial evidenceChicago, IL, United StatesHQ checked Sep 21, 2026501-1,000874 contacts →

Partial evidence

“Trustwave, a LevelBlue Company, is a globally recognized cybersecurity leader that reduces cyber risk and fortifies organizations against disruptive and damaging cyber threats.”

Source: RevenueBase Database · checked Sep 21, 2026
11Indirect evidenceKansas City, MO, United StatesHQ checked Sep 21, 20261,001-5,000844 contacts →

Indirect evidence

“Today’s threatscape is relentless.”

Source: RevenueBase Database · checked Sep 21, 2026
12Partial evidenceTampa, FL, United StatesHQ checked Sep 21, 2026501-1,000798 contacts →

Partial evidence

“A-LIGN is the leading provider of high-quality, efficient cybersecurity compliance programs.”

Source: RevenueBase Database · checked Sep 21, 2026
13Partial evidenceMumbai, IndiaHQ checked Sep 21, 2026501-1,000763 contacts →

Partial evidence

“With 35 years of experience, Softcell Technologies Global is a trusted IT services provider specialising in (i) IT security and cybersecurity solutions,(ii) cloud / on-premise…”

Source: RevenueBase Database · checked Sep 21, 2026
14Partial evidenceBengaluru, IndiaHQ checked Sep 21, 2026201-500743 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 21, 2026
15Indirect evidenceLondon, United KingdomHQ checked Sep 21, 2026n/a705 contacts →

Indirect evidence

“Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.”

Source: RevenueBase Database · checked Sep 21, 2026
16Indirect evidenceWaterloo, ON, CanadaHQ checked Sep 21, 2026501-1,000649 contacts →

Indirect evidence

“eSentire is a leader in Controlled Autonomy SecOps, protecting organizations across 35+ industries around the world.”

Source: RevenueBase Database · checked Sep 21, 2026
17Indirect evidencePlano, TX, United StatesHQ checked Sep 21, 2026501-1,000641 contacts →

Indirect evidence

“At Network Intelligence, we combine our team of 500+ security professionals with Transilience – our cutting-edge AI platform.”

Source: RevenueBase Database · checked Sep 21, 2026
18Partial evidenceCourbevoie, FranceHQ checked Sep 21, 20261,001-5,000639 contacts →

Partial evidence

“I-TRACING, pure player and cybersecurity service provider leader in France, supports over 600 clients around the world in managing their cyber risks, from anticipating threats to…”

Source: RevenueBase Database · checked Sep 21, 2026
19Indirect evidenceHerndon, United StatesHQ checked Sep 21, 20261,001-5,000636 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 21, 2026
20Indirect evidenceAshburn, VA, United StatesHQ checked Sep 21, 2026501-1,000629 contacts →

Indirect evidence

“Telos Corporation (NASDAQ: TLS) empowers and protects the world’s most security-conscious organizations with efficient, adaptable, and secure solutions that safeguard people…”

Source: RevenueBase Database · checked Sep 21, 2026
21Partial evidenceChicago, IL, United StatesHQ checked Sep 21, 20261,001-5,000628 contacts →

Partial evidence

“VikingCloud delivers battle-tested cybersecurity and compliance solutions that simply work.”

Source: RevenueBase Database · checked Sep 21, 2026
22Partial evidenceParis, ItalyHQ checked Sep 21, 2026501-1,000586 contacts →

Partial evidence

“Advens is a European, independent and outstanding leader in cybersecurity.”

Source: RevenueBase Database · checked Sep 21, 2026
23Indirect evidenceNew York, NY, United StatesHQ checked Sep 21, 2026501-1,000535 contacts →

Indirect evidence

“Funded by world-class investors, including Evolution Equity Partners, Silver Lake Partners, Sequoia Capital, GV, Riverwood Capital, and others, SecurityScorecard is the global…”

Source: RevenueBase Database · checked Sep 21, 2026
24Partial evidenceSingaporeHQ checked Sep 21, 2026501-1,000528 contacts →

Partial evidence

“Founded in 2003 and headquartered in Singapore, Group-IB is a leading creator of cybersecurity technologies to investigate, prevent, and fight digital crime.”

Source: RevenueBase Database · checked Sep 21, 2026
25Indirect evidenceDubai, United Arab EmiratesHQ checked Sep 21, 2026201-500525 contacts →

Indirect evidence

“Protection is Paramount!”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 13,905 cybersecurity audit firms worldwide

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Cybersecurity audit firms worldwide at a glance

As of Sep 21, 2026
27.6%Verified-email coverage
11.6Average contacts per company
1-10Median size (employees)
2.5%Largest-city concentration · London
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
8,242
11-50
4,380
51-200
963
201-500
205
501-1,000
44
1,001-5,000
38
5,001-10,000
8
10001+
9

Email recency is reported on each country list linked below.

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 audit 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.
Coverage
Every country. Country and city lists for cybersecurity audit firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “cybersecurity audit 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 audit 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 audit firms, and records with no verified work email.
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, 44,473 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 21, 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 audit firms by location

90 lists · largest first

Every Cybersecurity audit firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 audit 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 audit firms are there worldwide?

RevenueBase identified 13,905 cybersecurity audit firms worldwide 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?

Private Sector, headquartered in Worldwide, tops this list with the largest team on record.

Which country has the most cybersecurity audit firms?

The United States leads with 3,341 companies, followed by India (1,322) and the United Kingdom (871). Every cybersecurity audit firms list by country and city is linked on this page.

Which city has the most cybersecurity audit firms?

London leads with 354 headquartered companies, followed by Paris (157) and Sao Paulo (135).

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 44,473 verified decision-maker contacts tracked across these 13,905 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 21, 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.