Company lists · Data refreshed September 2026
Top 25 Due diligence companies worldwide
RevenueBase identified 441 due diligence companies worldwide as of September 2026 and tracks 4,684 professional contacts across them, including 1,181 with verified work emails. The United States is the largest market and London the largest hub.
This list covers due diligence companies 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 due diligence companies 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 companies worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 264 contacts → | ||||
Strong evidence “iCOVER Group provides high-quality Third-Party Background Screening, Monitoring, and Due Diligence services.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 3 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 4 | 142 contacts → | ||||
Strong evidence “PSA is a global due diligence and investigations firm headquartered in Washington, DC.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 6 | 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 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 107 contacts → | ||||
Strong evidence “Alias Intelligence is a leading background investigations and due diligence company delivering the information and insights our clients need to grow and navigate their businesses.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 75 contacts → | ||||
Strong evidence “Blue Heron Research Partners is an international leader in qualitative due diligence.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 67 contacts → | ||||
Indirect evidence “Matrix3D, a CERT-In Empanelled organization, helps make your business secure and resilient through detailed IT assessments and audits, with clear gap analysis and strong…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 10 | 66 contacts → | ||||
Indirect evidence “Investigative Group International (IGI) is the premier investigative firm conducting independent, high-touch investigations worldwide.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 65 contacts → | ||||
Indirect evidence “ITGS is a global risk intelligence and business assurance company dedicated to helping organizations make informed, confident, and compliant decisions.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 12 | 63 contacts → | ||||
Indirect evidence “Integrity Indonesia, established in 2001, provides reliable fraud prevention, detection, and investigation services to organizations across Southeast Asia and beyond.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 62 contacts → | ||||
Indirect evidence “Live investigator-led analysis is the best way to minimize regulatory, reputational and financial risks.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 58 contacts → | ||||
Strong evidence “Due Diligence AI that runs comprehensive financial, legal, regulatory and reputational risk analysis on any given target.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 49 contacts → | ||||
Strong evidence “Ironsides is an M&A advisory firm focused exclusively on providing transaction services including financial and accounting due diligence, tax due diligence and structuring…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 48 contacts → | ||||
Indirect evidence “Open Desk is a comprehensive research, compliance, and consulting firm dedicated to empowering clients through unbiased information and insights.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 39 contacts → | ||||
Strong evidence “The Search Group (TSG) specializes in due diligence and business intelligence.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 39 contacts → | ||||
Strong evidence “Premier Consultancy & Investigation is a Risk Advisory Consultancy that conducts international due diligence investigations that help clients make better decisions by selecting…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 38 contacts → | ||||
Indirect evidence “We provide real results, real quick.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 20 | 37 contacts → | ||||
Indirect evidence “CDS is now part of CrossCountry Consulting.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 35 contacts → | ||||
Strong evidence “At VENOVOX, we are a premier consultancy in risk management and background screening, delivering specialised services in due diligence, security advisory, background checks, and…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 31 contacts → | ||||
Indirect evidence “Our mission at Pinnacle Investigations is to provide accurate, timely, compliant background reports to aid our clients in building a safe, secure workplace.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 30 contacts → | ||||
Indirect evidence “As a national Information Security and Compliance firm, 10-D specializes in serving financial institutions, and has for 19 years.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 29 contacts → | ||||
Indirect evidence “Pohlmann & Company is one of the leading interdisciplinary and internationally active law and consulting firms with a clear focus on compliance, governance and investigations.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 24 contacts → | ||||
Strong evidence “Ground Truth Intelligence is the global due diligence platform designed for an ever-changing world.” Source: RevenueBase Database · checked Sep 21, 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 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 due diligence companies.
- Partial evidence
- Its own public description names part of due diligence companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name due diligence 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 441 due diligence companies worldwide
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Due diligence companies worldwide at a glance
As of Sep 21, 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 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.
- Coverage
- Every country. Country and city lists for due diligence companies are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “due diligence 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 due diligence 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 due diligence companies, 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, 1,181 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.
Due diligence companies by location
3 lists · largest firstEvery Due diligence companies list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
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 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 due diligence companies are there worldwide?
RevenueBase identified 441 due diligence companies 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?
Guidepost Solutions, headquartered in New York, tops this list with the largest team on record.
Which country has the most due diligence companies?
The United States leads with 135 companies, followed by India (37) and the United Kingdom (26). Every due diligence companies list by country and city is linked on this page.
Which city has the most due diligence companies?
London leads with 15 headquartered companies, followed by New York (14) and Sao Paulo (10).
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 1,181 verified decision-maker contacts tracked across these 441 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.