Company lists · Data refreshed September 2026

Top 25 Iso audit consulting firms based in the United States

Name: Iso audit consulting firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 1,854 companies tracked

RevenueBase identified 1,854 iso audit consulting firms headquartered in the United States as of September 2026 and tracks 34,558 professional contacts across them, including 13,217 with verified work emails. Houston is the largest hub.

This list covers iso audit consulting firms headquartered in the United States, 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 28, 2026.

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 28, 2026 86% judged on-target in blind review

1,854Companies

34,558Contacts tracked

13,217Verified emails

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The 25 largest iso audit consulting firms based in the United States

Ranked by team size

Top 25 of 1,854 iso audit consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to iso audit consulting 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	UL Solutions	Indirect evidence	Northbrook, IL, United StatesHQ checked Sep 28, 2026	10001+	12,316 contacts →
	Indirect evidence “A global leader in applied safety science, UL Solutions (NYSE: ULS) transforms safety, security and sustainability challenges into opportunities for customers in more than 110…” Source: RevenueBase Database · checked Sep 28, 2026
2	Sikich	Partial evidence	Chicago, IL, United StatesHQ checked Sep 28, 2026	1,001-5,000	1,688 contacts →
	Partial evidence “Sikich offers the public and private sectors a diverse platform of professional services across consulting, technology, and compliance.” Source: RevenueBase Database · checked Sep 28, 2026
3	Applied Technical Services, LLC	Partial evidence	Marietta, GA, United StatesHQ checked Sep 28, 2026	1,001-5,000	890 contacts →
	Partial evidence “Applied Technical Services assists commercial and industrial clients by providing inspection, testing, consulting engineering, and calibration services.” Source: RevenueBase Database · checked Sep 28, 2026
4	A-Lign	Indirect evidence	Tampa, FL, United StatesHQ checked Sep 28, 2026	501-1,000	798 contacts →
	Indirect evidence “A-LIGN is the leading provider of high-quality, efficient cybersecurity compliance programs.” Source: RevenueBase Database · checked Sep 28, 2026
5	TÜV Rheinland North America	Indirect evidence	Boxborough, MA, United StatesHQ checked Sep 28, 2026	501-1,000	712 contacts →
	Indirect evidence “TÜV Rheinland is a world leader in testing, inspection and certification services for a wide variety of industries.” Source: RevenueBase Database · checked Sep 28, 2026
6	Uniqus Consultech INC	Partial evidence	San Jose, CA, United StatesHQ checked Sep 28, 2026	501-1,000	675 contacts →
	Partial evidence “Uniqus Consultech is an AI and global tech-enabled consulting company that specializes in Accounting & Reporting Consulting, Governance, Risk & Compliance, Sustainability &…” Source: RevenueBase Database · checked Sep 28, 2026
7	Schellman	Indirect evidence	Tampa, FL, United StatesHQ checked Sep 28, 2026	501-1,000	516 contacts →
	Indirect evidence “Schellman is a leading provider of attestation and compliance services.” Source: RevenueBase Database · checked Sep 28, 2026
8	Socotec US	Indirect evidence	New York, NY, United StatesHQ checked Sep 28, 2026	1,001-5,000	492 contacts →
	Indirect evidence “Welcome to SOCOTEC in the US, Trusted Expertise, From the Ground Up.” Source: RevenueBase Database · checked Sep 28, 2026
9	Safety Management Group	Indirect evidence	Indianapolis, IN, United StatesHQ checked Sep 28, 2026	201-500	485 contacts →
	Indirect evidence “We are people-centric Quality, Health, Safety, and Environmental (QHSE) consultants driven to reduce risk, foster sustainable operations, and enhance safety culture to protect…” Source: RevenueBase Database · checked Sep 28, 2026
10	Controlcase	Indirect evidence	Fairfax, VA, United StatesHQ checked Sep 28, 2026	201-500	411 contacts →
	Indirect evidence “ControlCase is committed to bringing peace of mind to the world’s IT compliance programs through our signature partnership approach, commitment to automation, and cost-effective…” Source: RevenueBase Database · checked Sep 28, 2026
11	Quality Professionals Q-Pros	Indirect evidence	TX, United StatesHQ checked Sep 28, 2026	501-1,000	347 contacts →
	Indirect evidence “Quality Professionals (Q-Pros) is a global independent software Quality Assurance and Testing services provider supporting enterprise and government organizations.” Source: RevenueBase Database · checked Sep 28, 2026
12	Brickred Systems	Partial evidence	Redmond, WA, United StatesHQ checked Sep 28, 2026	501-1,000	266 contacts →
	Partial evidence “BrickRed Systems is Microsoft Gold certified partner also one among the leading Information Technology (IT) Consulting firms of the present generation.” Source: RevenueBase Database · checked Sep 28, 2026
13	Vaisesika	Partial evidence	Carlsbad, CA, United StatesHQ checked Sep 28, 2026	201-500	266 contacts →
	Partial evidence “Vaisesika Consulting is a global tech and consulting firm that helps businesses transform their digital setups and stay compliant in a straightforward way.” Source: RevenueBase Database · checked Sep 28, 2026
14	Valsource INC	Indirect evidence	Downingtown, PA, United StatesHQ checked Sep 28, 2026	201-500	245 contacts →
	Indirect evidence “Since 1996, ValSource has worked with hundreds of pharmaceutical, biopharma, and medical device organizations around the world.” Source: RevenueBase Database · checked Sep 28, 2026
15	Intertek Building & Construction	Indirect evidence	Arlington Heights, IL, United StatesHQ checked Sep 28, 2026	10001+	241 contacts →
	Indirect evidence “Market Access.” Source: RevenueBase Database · checked Sep 28, 2026
16	Omnex INC	Indirect evidence	Ann Arbor, MI, United StatesHQ checked Sep 28, 2026	501-1,000	216 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
17	PRO QC International	Indirect evidence	Mchenry, IL, United StatesHQ checked Sep 28, 2026	501-1,000	211 contacts →
	Indirect evidence “Pro QC International provides tailored quality solutions with a human touch in 100 countries.” Source: RevenueBase Database · checked Sep 28, 2026
18	Lachman Consultant Services	Indirect evidence	Westbury, NY, United StatesHQ checked Sep 28, 2026	51-200	179 contacts →
	Indirect evidence “Quality & Compliance \| Regulatory Strategy \| Inspection Readiness & Remediation \| Data Integrity.” Source: RevenueBase Database · checked Sep 28, 2026
19	Insight Assurance	Partial evidence	Tampa, FL, United StatesHQ checked Sep 28, 2026	201-500	174 contacts →
	Partial evidence “Insight Assurance is a security and compliance firm trusted by more than 1,500 organizations for their SOC 1, SOC 2, SOC 3, PCI DSS, ISO 27001, ISO 27017/27018, ISO 27701, ISO…” Source: RevenueBase Database · checked Sep 28, 2026
20	Ampcus Cyber	Indirect evidence	Chantilly, VA, United StatesHQ checked Sep 28, 2026	1,001-5,000	170 contacts →
	Indirect evidence “Trusted By 2,880+ World-Class Brands And Organizations Of All Sizes…!” Source: RevenueBase Database · checked Sep 28, 2026
21	Dla, LLC	Indirect evidence	Fairfield, NJ, United StatesHQ checked Sep 28, 2026	201-500	165 contacts →
	Indirect evidence “DLA, LLC is a leading consultancy firm that provides a wide range of specialized services designed to optimize business operations and drive sustainable growth.” Source: RevenueBase Database · checked Sep 28, 2026
22	Qualspec	Indirect evidence	Deer Park, TX, United StatesHQ checked Sep 28, 2026	1,001-5,000	149 contacts →
	Indirect evidence “QualSpec is a leading industrial inspection firm headquartered in Houston, Texas.” Source: RevenueBase Database · checked Sep 28, 2026
23	Jain & Associates	Indirect evidence	Los Angeles, CA, United StatesHQ checked Sep 28, 2026	n/a	146 contacts →
	Indirect evidence “The CPAs and staff accountants at Jain & Associates have an experience in both public accounting and industry.” Source: RevenueBase Database · checked Sep 28, 2026
24	Kirkpatrickprice	Indirect evidence	Nashville, TN, United StatesHQ checked Sep 28, 2026	51-200	139 contacts →
	Indirect evidence “KirkpatrickPrice is a licensed information security CPA firm, a PCI QSA, and a HITRUST CSF Assessor, providing assurance services to over clients worldwide.” Source: RevenueBase Database · checked Sep 28, 2026
25	Cotton	Partial evidence	Alexandria, VA, United StatesHQ checked Sep 28, 2026	201-500	134 contacts →
	Partial evidence “Cotton is an audit and accounting firm located in Old Town Alexandria, VA.” Source: RevenueBase Database · checked Sep 28, 2026

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: iso audit consulting 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 iso audit consulting firms.
Partial evidence: Its own public description names part of iso audit consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name iso audit consulting 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 1,854 iso audit consulting firms based in the United States

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Iso audit consulting firms based in the United States at a glance

As of Sep 28, 2026

38.2%Verified-email coverage

18.6Average contacts per company

1-10Median size (employees)

4.5%Largest-city concentration · Houston

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

1,261

11-50

422

51-200

102

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

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 1,854 companies.

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 iso audit consulting 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.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “iso audit consulting 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 iso audit consulting 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 iso audit consulting firms, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
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, 13,217 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 28, 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.

Iso audit consulting firms by metro

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 iso audit consulting 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 iso audit consulting firms are there based in the United States?

RevenueBase identified 1,854 iso audit consulting firms headquartered in the United States 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?

UL Solutions, headquartered in Northbrook, tops this list with the largest team on record.

Which city has the most iso audit consulting firms?

Houston leads with 84 headquartered companies, followed by New York (43) and Los Angeles (32).

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 13,217 verified decision-maker contacts tracked across these 1,854 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 28, 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.