Company lists · Data refreshed September 2026
Top 25 Due diligence firms worldwide
RevenueBase identified 2,451 due diligence firms worldwide as of September 2026 and tracks 28,960 professional contacts across them, including 7,291 with verified work emails. The United States is the largest market and London the largest hub.
This list covers due diligence 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 19, 2026. Country and city lists for due diligence 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.
The 25 largest due diligence firms worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,332 contacts → | ||||
Indirect evidence “DataFlow Group is a pioneering global provider of specialized Primary Source Verification (PSV) solutions, and background screening and immigration compliance services that assist…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 677 contacts → | ||||
Indirect evidence “OMNIPLEX World Services Corporation is a leader and innovator in delivering professional background investigations, intelligence support, and physical security services to…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 667 contacts → | ||||
Indirect evidence “cFIRST is a digital global background screening service provider headquartered in Cincinnati, Ohio.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 477 contacts → | ||||
Indirect evidence “Empowering Confident Hiring Decisions for 15+ Years Verifacts is India’s trusted background verification partner-delivering accurate, customizable checks across employees…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 449 contacts → | ||||
Indirect evidence “First Advantage India is the nation’s leading Background Screening Service.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 408 contacts → | ||||
Indirect evidence “Sterling was acquired by First Advantage on October 31st, 2024.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 336 contacts → | ||||
Indirect evidence “Vcheck is a global investigations firm that helps institutions protect their investments by providing intelligence on individuals and entities.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 308 contacts → | ||||
Indirect evidence “At Comply, we pride ourselves on being the champion for compliance professionals.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 268 contacts → | ||||
Indirect evidence “We stand at the forefront of leadership, insight, and guidance in a world marked by complexity and uncertainty.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 264 contacts → | ||||
Strong evidence “iCOVER Group provides high-quality Third-Party Background Screening, Monitoring, and Due Diligence services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 242 contacts → | ||||
Indirect evidence “We help our customers to do the right business in the right way.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 241 contacts → | ||||
Indirect evidence “We know you work hard to get the best deal possible.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 218 contacts → | ||||
Indirect evidence “IIRIS operating under its distinct business offerings "IntelliRisk"(IR),"IntelliSense"(IS),"Security Design" and "Brand Protection" seeks to provide comprehensive intelligence…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 214 contacts → | ||||
Indirect evidence “Frasco has hundreds of investigators and regional offices located throughout the country.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 214 contacts → | ||||
Indirect evidence “Xpera has been a trusted partner to businesses and governments for over 50 years.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 195 contacts → | ||||
Indirect evidence “Forensic Risk Alliance (FRA) is an international consultancy that combines forensic accounting and forensic technology expertise to position businesses for success with…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 195 contacts → | ||||
Indirect evidence “At IISERVZ, we're not just providing a service; we're delivering a solution.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 159 contacts → | ||||
Strong evidence “By leveraging cutting-edge technology and experienced analysts, Neotas are going beyond and setting new standards in Due Diligence, Staff Screening, and Compliance.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 156 contacts → | ||||
Indirect evidence “Justis werkt aan een veiligere en rechtvaardigere samenleving door het screenen van personen en organisaties.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 146 contacts → | ||||
Indirect evidence “A federally qualified Small Business, IDS offers end to end investigative solutions tailored to meet the specific needs of our clients.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 142 contacts → | ||||
Strong evidence “PSA is a global due diligence and investigations firm headquartered in Washington, DC.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 141 contacts → | ||||
Indirect evidence “TrendSource helps businesses document and measure compliance across employment, consumer reporting, government, finance, health care, and retail.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 140 contacts → | ||||
Strong evidence “Corporate Research and Investigations Limited is a global provider of investigative research, background screening and business due diligence services for the world’s leading…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 137 contacts → | ||||
Indirect evidence “Vault Workforce Screening was acquired by Sterling on January 2, 2024.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 131 contacts → | ||||
Indirect evidence “AMS Inform Empowering Global Background Screening Solutions At AMS Inform, we are a powerhouse of global background screening services, revolutionizing the industry from India.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
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: due diligence firms. 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 due diligence firms.
- Partial evidence
- Its own public description names part of due diligence firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name due diligence firms. 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 2,451 due diligence firms worldwide
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Due diligence firms worldwide at a glance
As of Sep 19, 2026Companies by employee count
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 due diligence 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 due diligence firms are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “due diligence 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 due diligence 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 due diligence 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, 7,291 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 19, 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.
Due diligence firms by location
11 lists · largest firstEvery Due diligence firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Due diligence firms based in the United States777
- Due diligence firms based in India234
- Due diligence firms based in the United Kingdom156
- Due diligence firms based in Italy82
- Due diligence firms based in Brazil63
- Due diligence firms based in South Africa62
- Due diligence firms based in Canada57
- Due diligence firms based in France50
- Due diligence firms based in Australia49
- Due diligence firms based in the Netherlands42
- Due diligence firms based in Spain25
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 due diligence 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 due diligence firms are there worldwide?
RevenueBase identified 2,451 due diligence 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?
Dataflow Group, headquartered in Dubai, tops this list with the largest team on record.
Which country has the most due diligence firms?
The United States leads with 777 companies, followed by India (234) and the United Kingdom (156). Every due diligence firms list by country and city is linked on this page.
Which city has the most due diligence firms?
London leads with 78 headquartered companies, followed by New York (50) and Sao Paulo (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 7,291 verified decision-maker contacts tracked across these 2,451 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 19, 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.