Company lists · Data refreshed September 2026
Top 25 Due diligence investigation firms worldwide
RevenueBase identified 856 due diligence investigation firms worldwide as of September 2026 and tracks 8,518 professional contacts across them, including 1,788 with verified work emails. The United States is the largest market and London the largest hub.
This list covers due diligence investigation 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 investigation 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 investigation firms worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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. | |||||
| 2 | 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. | |||||
| 3 | 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. | |||||
| 4 | 146 contacts → | ||||
Partial 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. | |||||
| 5 | 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. | |||||
| 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 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 117 contacts → | ||||
Partial evidence “FACT are at the forefront of investigative and intelligence services, recognised by organisations, law enforcement, and governments worldwide.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 115 contacts → | ||||
Indirect evidence “Evaluationz India Pvt Ltd is a background Verification and Assessment firm.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 112 contacts → | ||||
Indirect evidence “Every decision carries a risk.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 108 contacts → | ||||
Strong evidence “Africa's Leading Background Screening and Due Diligence Company, built on trust for people and enterprise.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 81 contacts → | ||||
Strong evidence “VERIS is a professional background screening and due diligence company supporting organizations in making informed, risk-aware decisions.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 81 contacts → | ||||
Indirect evidence “Crystal Screening Services – Secure Your Workforce with Confidence In today’s fast-moving business environment, hiring the right people isn’t just important-it’s critical.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 75 contacts → | ||||
Strong evidence “Blue Heron Research Partners is an international leader in qualitative due diligence.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 72 contacts → | ||||
Indirect evidence “Integrated Security Services, Inc.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 67 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, 2026Thanks. The Data Team will review it. | |||||
| 17 | 67 contacts → | ||||
Indirect evidence “Welcome to Vibrant Screen - Count on us for all your background verification needs.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 66 contacts → | ||||
Indirect evidence “SI helps clients manage their risk with background reports for employment screening, business transactions, and client acceptance.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 62 contacts → | ||||
Indirect evidence “Live investigator-led analysis is the best way to minimize regulatory, reputational and financial risks.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 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 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 57 contacts → | ||||
Partial evidence “Go Beyond Traditional Background Screening and Investigative Services: TruView is the nexus where the most modern technologies meet expert human analysis to achieve client success.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 54 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, 2026Thanks. The Data Team will review it. | |||||
| 24 | 51 contacts → | ||||
Strong evidence “MASRI, originally established in 1950, is the oldest established, largest, and leading firm in the MENA and GCC in the field of due diligence, background checks, commercial…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 51 contacts → | ||||
Strong evidence “Established in 2007 and headquartered in Singapore, Back Check Group is a global provider of integrity, reputation and compliance management services, due diligence background…” 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 investigation 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 investigation firms.
- Partial evidence
- Its own public description names part of due diligence investigation 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 investigation 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 856 due diligence investigation firms worldwide
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 1,788 reachable decision-makers.
Free signup · no credit card
Due diligence investigation 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 investigation 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 investigation firms are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “due diligence investigation 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 investigation 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 investigation 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, 1,788 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 investigation firms by location
3 lists · largest firstEvery Due diligence investigation 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 investigation 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 investigation firms are there worldwide?
RevenueBase identified 856 due diligence investigation 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?
Icover Services, headquartered in Paris, tops this list with the largest team on record.
Which country has the most due diligence investigation firms?
The United States leads with 270 companies, followed by India (117) and the United Kingdom (46). Every due diligence investigation firms list by country and city is linked on this page.
Which city has the most due diligence investigation firms?
London leads with 27 headquartered companies, followed by New York (21) and Mumbai (12).
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 1,788 verified decision-maker contacts tracked across these 856 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.
Ready to reach these companies? Verified emails and direct dials for all 856 due diligence investigation firms worldwide. Start with a free account, no credit card.
Download this list →Related lists
Browse the directory
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.