Company lists · Data refreshed September 2026

Top 25 Due diligence research firms worldwide

RevenueBase identified 572 due diligence research firms worldwide as of September 2026 and tracks 6,025 professional contacts across them, including 1,528 with verified work emails. The United States is the largest market and London the largest hub.

This list covers due diligence research 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 research 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 19, 2026 86% judged on-target in blind review
572Companies
6,025Contacts tracked
1,528Verified emails
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The 25 largest due diligence research firms worldwide

Ranked by team size
Top 25 of 572 due diligence research firms worldwide, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to due diligence research 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 evidenceMumbai, IndiaHQ checked Sep 19, 20261,001-5,000449 contacts →

Indirect evidence

“First Advantage India is the nation’s leading Background Screening Service.”

Source: RevenueBase Database · checked Sep 19, 2026
2Indirect evidence新加坡, SingaporeHQ checked Sep 19, 202651-200341 contacts →

Indirect evidence

“BDA is an investment advisory firm founded in 1994, initially to serve Morgan Stanley and its clients then our own.”

Source: RevenueBase Database · checked Sep 19, 2026
3Strong evidenceParis, FranceHQ checked Sep 19, 2026201-500264 contacts →

Strong evidence

“iCOVER Group provides high-quality Third-Party Background Screening, Monitoring, and Due Diligence services.”

Source: RevenueBase Database · checked Sep 19, 2026
4Strong evidenceCleveland, OH, United StatesHQ checked Sep 19, 2026201-500207 contacts →

Strong evidence

“Blue Umbrella is a leading provider of due diligence research and regulatory compliance technologies.”

Source: RevenueBase Database · checked Sep 19, 2026
5Strong evidenceLondon, United KingdomHQ checked Sep 19, 202651-200159 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, 2026
6Indirect evidenceFort Worth, TX, United StatesHQ checked Sep 19, 202651-200146 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, 2026
7Strong evidenceWashington, DC, United StatesHQ checked Sep 19, 202651-200142 contacts →

Strong evidence

“PSA is a global due diligence and investigations firm headquartered in Washington, DC.”

Source: RevenueBase Database · checked Sep 19, 2026
8Strong evidenceLondon, United KingdomHQ checked Sep 19, 202651-200140 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, 2026
9Indirect evidenceNew York, NY, United StatesHQ checked Sep 19, 202651-200120 contacts →

Indirect evidence

“Intelligo is the world’s leading risk intelligence platform, blending artificial intelligence and human expert analysis to generate a 360° view of any person or company.”

Source: RevenueBase Database · checked Sep 19, 2026
10Strong evidenceLos Angeles, TX, United StatesHQ checked Sep 19, 202651-200107 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 19, 2026
11Strong evidenceNew York, NY, United StatesHQ checked Sep 19, 202651-20075 contacts →

Strong evidence

“Blue Heron Research Partners is an international leader in qualitative due diligence.”

Source: RevenueBase Database · checked Sep 19, 2026
12Strong evidenceMedford, OR, United StatesHQ checked Sep 19, 202611-5067 contacts →

Strong evidence

“Ashland Partners & Company LLP is a PCAOB registered, specialty CPA firm providing due diligence solutions to the investment management industry.”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceDubai, United Arab EmiratesHQ checked Sep 19, 202651-20065 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 19, 2026
14Indirect evidenceCincinnati, OH, United StatesHQ checked Sep 19, 202611-5062 contacts →

Indirect evidence

“Live investigator-led analysis is the best way to minimize regulatory, reputational and financial risks.”

Source: RevenueBase Database · checked Sep 19, 2026
15Strong evidenceHyderabad, IndiaHQ checked Sep 19, 202611-5058 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 19, 2026
16Strong evidenceGurugram, IndiaHQ checked Sep 19, 202651-20054 contacts →

Strong evidence

“Founded in October 2003, Alea Consulting supports clients with focused governance, compliance, integrity due diligence, and corporate intelligence.”

Source: RevenueBase Database · checked Sep 19, 2026
17Indirect evidenceHong KongHQ checked Sep 19, 202651-20048 contacts →

Indirect evidence

“Blackpeak is dedicated to uncovering critical risks for our clients worldwide.”

Source: RevenueBase Database · checked Sep 19, 2026
18Strong evidenceNew York, NY, United StatesHQ checked Sep 19, 202651-20042 contacts →

Strong evidence

“Hilton Global Associates is a professional investigative research firm providing expert due diligence and unparalleled client service.”

Source: RevenueBase Database · checked Sep 19, 2026
19Strong evidenceHong KongHQ checked Sep 19, 202651-20039 contacts →

Strong evidence

“The Search Group (TSG) specializes in due diligence and business intelligence.”

Source: RevenueBase Database · checked Sep 19, 2026
20Strong evidenceNew Delhi, IndiaHQ checked Sep 19, 202651-20039 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 19, 2026
21Indirect evidenceUnited StatesHQ checked Sep 19, 202651-20038 contacts →

Indirect evidence

“We provide real results, real quick.”

Source: RevenueBase Database · checked Sep 19, 2026
22Partial evidenceLondon, United KingdomHQ checked Sep 19, 202651-20038 contacts →

Partial evidence

“ICP is an independent, human-led research firm providing decision-grade intelligence on companies operating in markets where reliable data cannot be trusted.”

Source: RevenueBase Database · checked Sep 19, 2026
23Strong evidenceBoston, MA, United StatesHQ checked Sep 19, 202611-5037 contacts →

Strong evidence

“Fairmont Consulting Group is a Boston-based firm focused on due diligence and strategic advisory services for clients active in aerospace, defense, government services, and the…”

Source: RevenueBase Database · checked Sep 19, 2026
24Indirect evidenceSan Francisco, CA, United StatesHQ checked Sep 19, 202611-5037 contacts →

Indirect evidence

“CDS is now part of CrossCountry Consulting.”

Source: RevenueBase Database · checked Sep 19, 2026
25Strong evidenceLuxembourgHQ checked Sep 19, 202611-5035 contacts →

Strong evidence

“Founded in 2010, Sqope is a leading provider of enhanced due diligence reports on individuals and companies that empower professionals to evaluate risk and make decisions.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 572 due diligence research firms worldwide

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Due diligence research firms worldwide at a glance

As of Sep 19, 2026
25.4%Verified-email coverage
10.5Average contacts per company
1-10Median size (employees)
4.4%Largest-city concentration · London
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
349
11-50
167
51-200
45
201-500
8
1,001-5,000
2

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 research 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 research firms are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “due diligence research 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 research 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 research 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, 1,528 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 research firms by location

6 lists · largest first

Every Due diligence research firms 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 research 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 research firms are there worldwide?

RevenueBase identified 572 due diligence research 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?

First Advantage India, headquartered in Mumbai, tops this list with the largest team on record.

Which country has the most due diligence research firms?

The United States leads with 200 companies, followed by India (43) and the United Kingdom (38). Every due diligence research firms list by country and city is linked on this page.

Which city has the most due diligence research firms?

London leads with 25 headquartered companies, followed by New York (24) and Washington (9).

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 1,528 verified decision-maker contacts tracked across these 572 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.