Company lists · Data refreshed September 2026

Top 25 Due diligence firms based in the United States

RevenueBase identified 777 company matches for due diligence firms associated with the United States as of September 2026 and tracks 10,656 professional contacts across them, including 3,489 with verified work emails. New York is the largest hub.

This list covers company matches for due diligence firms associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 19, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Sep 19, 2026 How this list was built
777Companies
10,656Contacts tracked
3,489Verified emails
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The 25 largest due diligence firms based in the United States

Ranked by team size
Top 25 of 777 company matches for due diligence firms based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 19, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchHerndon, VA, United StatesHQ recorded Sep 19, 20261,001-5,000677 contacts →

Exact match

“OMNIPLEX World Services Corporation is a leader and innovator in delivering professional background investigations, intelligence support, and physical security services to…”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
2Exact matchCincinnati, OH, United StatesHQ recorded Sep 19, 2026201-500667 contacts →

Exact match

“cFIRST is a digital global background screening service provider headquartered in Cincinnati, Ohio.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
3Exact matchNew York, NY, United StatesHQ recorded Sep 19, 2026201-500336 contacts →

Exact match

“Vcheck is a global investigations firm that helps institutions protect their investments by providing intelligence on individuals and entities.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
4Exact matchNew York, NY, United StatesHQ recorded Sep 19, 2026201-500308 contacts →

Exact match

“At Comply, we pride ourselves on being the champion for compliance professionals.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
5Exact matchNew York, NY, United StatesHQ recorded Sep 19, 2026201-500268 contacts →

Exact match

“We stand at the forefront of leadership, insight, and guidance in a world marked by complexity and uncertainty.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
6Exact matchHowell, NJ, United StatesHQ recorded Sep 19, 2026n/a241 contacts →

Exact match

“We know you work hard to get the best deal possible.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
7Exact matchIrvine, CA, United StatesHQ recorded Sep 19, 2026201-500214 contacts →

Exact match

“Frasco has hundreds of investigators and regional offices located throughout the country.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
8Exact matchFort Worth, TX, United StatesHQ recorded Sep 19, 202651-200146 contacts →

Exact match

“A federally qualified Small Business, IDS offers end to end investigative solutions tailored to meet the specific needs of our clients.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
9Exact matchWashington, DC, United StatesHQ recorded Sep 19, 202651-200142 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
10Exact matchSan Diego, CA, United StatesHQ recorded Sep 19, 202611-50141 contacts →

Exact match

“TrendSource helps businesses document and measure compliance across employment, consumer reporting, government, finance, health care, and retail.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
11Exact matchCoral Gables, FL, United StatesHQ recorded Sep 19, 2026201-500137 contacts →

Exact match

“Vault Workforce Screening was acquired by Sterling on January 2, 2024.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
12Exact matchNew York, NY, United StatesHQ recorded Sep 19, 202651-200112 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
13Exact matchLos Angeles, TX, United StatesHQ recorded Sep 19, 202651-200107 contacts →

Exact match

“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.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
14Exact matchTroy, MI, United StatesHQ recorded Sep 19, 2026201-500104 contacts →

Exact match

“The Robison Group is an agency of professional investigators and support teams offering surveillance, SIU claims, business risk mitigation and comprehensive desktop investigation…”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
15Exact matchJersey City, NJ, United StatesHQ recorded Sep 19, 202651-20098 contacts →

Exact match

“Accume Partners, now part of Cherry Bekaert, is a trusted risk assurance and advisory leader and innovator in delivering integrated solutions to our clients in highly regulated…”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
16Exact matchWhite Plains, NY, United StatesHQ recorded Sep 19, 202651-20096 contacts →

Exact match

“Gryphon partners with clients across the globe to help them assess new opportunities and tackle their most complex problems often in challenging and opaque markets.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
17Exact matchLakeville, MN, United StatesHQ recorded Sep 19, 202651-20093 contacts →

Exact match

“Verified Credentials, LLC is a leading background screening company.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
18Exact matchBethesda, MD, United StatesHQ recorded Sep 19, 202651-20093 contacts →

Exact match

“RosettiStarr provides cutting-edge intelligence, investigations, corporate risk and cyber security services to management teams, attorneys and investors worldwide.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
19Exact matchJacksonville, FL, United StatesHQ recorded Sep 19, 20261,001-5,00093 contacts →

Exact match

“ICS Merrill has joined forces with GlobalOptions to created CoventBridge Group, the largest worldwide investigative services company providing: Surveillance, SIU and Compliance…”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
20Exact matchCordova, TN, United StatesHQ recorded Sep 19, 202651-20085 contacts →

Exact match

“Hiring decisions are more complex than ever.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
21Exact matchGold River, CA, United StatesHQ recorded Sep 19, 202651-20077 contacts →

Exact match

“CREtelligent’s Radius Platform is the world's first 24/7 "CRE Due Diligence Storefront." CREtelligent provides almost every due diligence service CRE buyers, lenders and sellers…”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
22Exact matchNew York, NY, United StatesHQ recorded Sep 19, 202651-20075 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
23Exact matchNew York, NY, United StatesHQ recorded Sep 19, 2026201-50072 contacts →

Exact match

“Integrated Security Services, Inc.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
24Exact matchConcord, CA, United StatesHQ recorded Sep 19, 202651-20070 contacts →

Exact match

“A recognized leader in forensic and financial consulting for more than 60 years.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase
25Exact matchMonaca, PA, United StatesHQ recorded Sep 19, 2026201-50069 contacts →

Exact match

“CSI is a full-service investigative firm that delivers key facts to give our clients an actionable advantage in a wide range of situations.”

Recorded in the RevenueBase company graph · Sep 19, 2026 · View company records in RevenueBase

Showing 25 of 777 due diligence firms based in the United States

See the full list, filter by size, metro and specialty, and access 3,489 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Due diligence firms based in the United States at a glance

As of Sep 19, 2026
32.7%Verified-email coverage
13.7Average contacts per company
1-10Median size (employees)
6.8%Largest-city concentration · New York
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
433
11-50
249
51-200
69
201-500
19
1,001-5,000
6

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 777 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United States whose business descriptions match “due diligence firms” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 3,489 professional contacts with verified work emails across the full matched dataset. 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.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “due diligence firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many due diligence firms are there based in the United States?

RevenueBase identified 777 company matches for due diligence firms associated with the United States as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Omniplex World Services Corporation tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most due diligence firms?

New York leads with 53 company records, followed by Washington (19) and Miami (18).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 3,489 professional contacts with verified work emails tracked across these 777 companies; direct dials are available where recorded.

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 SmartSearch, 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.