Company lists · Data refreshed September 2026

Top 25 Due diligence consulting companies worldwide

RevenueBase identified 837 due diligence consulting companies worldwide as of September 2026 and tracks 6,543 professional contacts across them, including 2,106 with verified work emails. The United States is the largest market and London the largest hub.

This list covers due diligence consulting 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 19, 2026. Country and city lists for due diligence consulting 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.

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
837Companies
6,543Contacts tracked
2,106Verified emails
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The 25 largest due diligence consulting companies worldwide

Ranked by team size
Top 25 of 837 due diligence consulting companies 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 consulting companies: 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 evidenceHowell, NJ, United StatesHQ checked Sep 19, 2026n/a241 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
2Indirect evidenceGoiânia, BrazilHQ checked Sep 19, 2026201-500234 contacts →

Indirect evidence

“A GAP Ambiental oferece serviços para pequenas, médias e grandes empresas em diversas áreas que vão desde o licenciamento ao acompanhamento da execução de projetos.”

Source: RevenueBase Database · checked Sep 19, 2026
3Partial evidenceChicago, IL, United StatesHQ checked Sep 19, 202651-200187 contacts →

Partial evidence

“DPO & Co specializes in helping Private Equity firms and their portfolio companies gain fact-based insights during the diligence process and realize post-close synergies and value…”

Source: RevenueBase Database · checked Sep 19, 2026
4Indirect evidenceTampa, FL, United StatesHQ checked Sep 19, 202651-200181 contacts →

Indirect evidence

“Maximizing Value.”

Source: RevenueBase Database · checked Sep 19, 2026
5Strong evidenceBoston, MA, United StatesHQ checked Sep 19, 202651-200168 contacts →

Strong evidence

“For over 25 years, IGS has helped investors and management teams make better, faster decisions, from commercial due diligence, to growth strategy, pricing, and go-to-market…”

Source: RevenueBase Database · checked Sep 19, 2026
6Strong 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
7Indirect evidenceParis, FranceHQ checked Sep 19, 2026201-500117 contacts →

Indirect evidence

“Talenz Audit accompagne les acteurs économiques, entreprises et organisations, dans leurs relations économiques, dans l’analyse de la fiabilité de leurs données financières, et…”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceBelo Horizonte, BrazilHQ checked Sep 19, 202651-200117 contacts →

Indirect evidence

“Founded in 2005, Hect is a Brazilian company with both national and international operations.”

Source: RevenueBase Database · checked Sep 19, 2026
9Partial evidenceLondon, United StatesHQ checked Sep 19, 2026201-500113 contacts →

Partial evidence

“Global PMI Partners is a specialist consulting firm supporting our listed company and private equity clients with their M&A integrations, divestments and operational…”

Source: RevenueBase Database · checked Sep 19, 2026
10Strong evidenceParis, FranceHQ checked Sep 19, 202651-200101 contacts →

Strong evidence

“Exelmans est un Cabinet de conseil et d’audit spécialisé dans la due diligence financière.”

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
12Indirect evidenceMumbai, IndiaHQ checked Sep 19, 202611-5069 contacts →

Indirect evidence

“Established in the year 1987, fully operational and growing exponentially since early 2003.”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceMoorestown, NJ, United StatesHQ checked Sep 19, 202651-20068 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 19, 2026
14Strong 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
15Indirect evidenceGrayslake, IL, United StatesHQ checked Sep 19, 202651-20064 contacts →

Indirect evidence

“LM Consultants, Inc.”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect 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
17Strong 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
18Indirect evidenceCourbevoie, FranceHQ checked Sep 19, 202611-5051 contacts →

Indirect evidence

“JLA est un cabinet d'expert engagés existant depuis plus de 30 ans et se structurant autour de différents domaines- Assistance comptable et fiscale- Assistance sociale- Assistance…”

Source: RevenueBase Database · checked Sep 19, 2026
19Strong evidenceSanta Monica, CA, United StatesHQ checked Sep 19, 202651-20049 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 19, 2026
20Strong evidenceDallas, TX, United StatesHQ checked Sep 19, 202651-20049 contacts →

Strong evidence

“Columbia Advisory Group is a Dallas, Texas based Information Technology consulting firm focused on providing Information Technology due diligence, strategic assessment and…”

Source: RevenueBase Database · checked Sep 19, 2026
21Indirect evidencePune, IndiaHQ checked Sep 19, 202611-5049 contacts →

Indirect evidence

“Virtuoso Infotech is a mission driven organization that is focused on making a positive impact on the world at scale, by leveraging Technology.”

Source: RevenueBase Database · checked Sep 19, 2026
22Indirect 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
23Strong evidenceAmsterdam, NetherlandsHQ checked Sep 19, 202611-5047 contacts →

Strong evidence

“SINCERIUS is frontrunner in data-driven due diligence.”

Source: RevenueBase Database · checked Sep 19, 2026
24Strong evidenceLondon, United KingdomHQ checked Sep 19, 202651-20047 contacts →

Strong evidence

“We empower private equity firms to make sound investment decisions with our award-winning digital due diligence, whilst supporting portfolio companies through necessary digital…”

Source: RevenueBase Database · checked Sep 19, 2026
25Strong evidenceLos Angeles, CA, United StatesHQ checked Sep 19, 20261,001-5,00047 contacts →

Strong evidence

“On the leading edge of innovation in commercial real estate transactions, GRS an NV5 Company is one of the largest national provider CRE due diligence services.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 837 due diligence consulting companies worldwide

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Due diligence consulting companies worldwide at a glance

As of Sep 19, 2026
32.2%Verified-email coverage
7.8Average contacts per company
1-10Median size (employees)
3.8%Largest-city concentration · London
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
551
11-50
227
51-200
45
201-500
10
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 consulting 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 consulting companies are linked below.
What qualifies
Companies worldwide whose own description of what they do matches “due diligence consulting 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 consulting 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 consulting 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, 2,106 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 consulting companies by location

5 lists · largest first

Every Due diligence consulting 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 consulting 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 consulting companies are there worldwide?

RevenueBase identified 837 due diligence consulting 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?

Gparency, headquartered in Howell, tops this list with the largest team on record.

Which country has the most due diligence consulting companies?

The United States leads with 249 companies, followed by India (56) and the United Kingdom (45). Every due diligence consulting companies list by country and city is linked on this page.

Which city has the most due diligence consulting companies?

London leads with 32 headquartered companies, followed by New York (22) and Sao Paulo (19).

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 2,106 verified decision-maker contacts tracked across these 837 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.