Company lists · Data refreshed September 2026

Top 25 Tax outsourcing companies based in the United States

Name: Tax outsourcing companies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 8,199 companies tracked

RevenueBase identified 8,199 tax outsourcing companies headquartered in the United States as of September 2026 and tracks 113,576 professional contacts across them, including 24,785 with verified work emails. New York is the largest hub.

This list covers tax outsourcing companies 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 21, 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 21, 2026 86% judged on-target in blind review

8,199Companies

113,576Contacts tracked

24,785Verified emails

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The 25 largest tax outsourcing companies based in the United States

Ranked by team size

Top 25 of 8,199 tax outsourcing companies based in the United States, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to tax outsourcing 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	H&r Block	Indirect evidence	Kansas City, MO, United StatesHQ checked Sep 21, 2026	10001+	59,451 contacts →
	Indirect evidence “H&R Block’s purpose is simple: To provide help and inspire confidence in our clients and communities everywhere.” Source: RevenueBase Database · checked Sep 21, 2026
2	RYAN	Partial evidence	Dallas, TX, United StatesHQ checked Sep 21, 2026	5,001-10,000	6,089 contacts →
	Partial evidence “Ryan, an award-winning global tax services and software provider, is the largest Firm in the world dedicated exclusively to business taxes.” Source: RevenueBase Database · checked Sep 21, 2026
3	Block Advisors	Indirect evidence	Kansas City, MO, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,379 contacts →
	Indirect evidence “We are Block Advisors by H&R Block.” Source: RevenueBase Database · checked Sep 21, 2026
4	DMA	Partial evidence	Fort Wayne, IN, United StatesHQ checked Sep 21, 2026	501-1,000	861 contacts →
	Partial evidence “Great Place to Work® Certified™ DMA, a proudly employee-owned company, has been solving corporate tax challenges for its clients since 1972.” Source: RevenueBase Database · checked Sep 21, 2026
5	Sensiba LLP	Partial evidence	San Jose, CA, United StatesHQ checked Sep 21, 2026	501-1,000	493 contacts →
	Partial evidence “Sensiba’s comprehensive accounting, tax, and consulting services help businesses and people solve problems, navigate complexity, and build a foundation for sustainable growth.” Source: RevenueBase Database · checked Sep 21, 2026
6	Smith Howard	Partial evidence	Atlanta, GA, United StatesHQ checked Sep 21, 2026	501-1,000	413 contacts →
	Partial evidence “Smith + Howard is a tax, accounting, advisory, and consulting firm headquartered in Atlanta, with a global presence.” Source: RevenueBase Database · checked Sep 21, 2026
7	Apercen Partners LLC	Partial evidence	Palo Alto, CA, United StatesHQ checked Sep 21, 2026	201-500	399 contacts →
	Partial evidence “Originating from the English and Latin roots of “apercu,” an act of insight, and “census,” an applied study of wealth and property, Apercen is a tax consulting firm offering high…” Source: RevenueBase Database · checked Sep 21, 2026
8	Cohesive	Indirect evidence	Exton, PA, United StatesHQ checked Sep 21, 2026	501-1,000	364 contacts →
	Indirect evidence “Cohesive is a leading solutions provider and systems integrator for IBM Maximo.” Source: RevenueBase Database · checked Sep 21, 2026
9	Advantage ONE TAX Consulting	Partial evidence	Sterling, VA, United StatesHQ checked Sep 21, 2026	201-500	347 contacts →
	Partial evidence “Advantage One Tax Consulting is a multi-disciplinary group of highly experienced tax professionals who understand the tax practice in its true spirit, examine the issues it faces…” Source: RevenueBase Database · checked Sep 21, 2026
10	1-800accountant	Indirect evidence	New York, NY, United StatesHQ checked Sep 21, 2026	201-500	320 contacts →
	Indirect evidence “1-800Accoutant is America’s leading virtual accounting firm for small businesses.” Source: RevenueBase Database · checked Sep 21, 2026
11	Unison Globus	Partial evidence	Coral Springs, FL, United StatesHQ checked Sep 21, 2026	201-500	320 contacts →
	Partial evidence “Unison Globus is a global accounting outsourcing and offshore staffing partner dedicated to supporting CPA firms and accounting professionals.” Source: RevenueBase Database · checked Sep 21, 2026
12	Squire	Partial evidence	Orem, UT, United StatesHQ checked Sep 21, 2026	201-500	297 contacts →
	Partial evidence “Squire is a nationally recognized audit, tax, and business advisory firm serving clients across the U.S.” Source: RevenueBase Database · checked Sep 21, 2026
13	GTM Global TAX Management	Partial evidence	Wayne, PA, United StatesHQ checked Sep 21, 2026	201-500	281 contacts →
	Partial evidence “GTM is a leading provider of corporate tax services.” Source: RevenueBase Database · checked Sep 21, 2026
14	Mayatax	Indirect evidence	Houston, TX, United StatesHQ checked Sep 21, 2026	501-1,000	269 contacts →
	Indirect evidence “Growth exposes financial weakness.” Source: RevenueBase Database · checked Sep 21, 2026
15	KE Andrews	Partial evidence	Dallas, TX, United StatesHQ checked Sep 21, 2026	201-500	224 contacts →
	Partial evidence “In operation since 1978, KE Andrews is one of the largest state and local tax firms in the country, managing over $500 billion in assets.” Source: RevenueBase Database · checked Sep 21, 2026
16	Zenwork, INC	Partial evidence	Fayetteville, AR, United StatesHQ checked Sep 21, 2026	51-200	206 contacts →
	Partial evidence “Zenwork, through its Tax1099 and Compliancely brands, is a fast-growing digital tax compliance and regulatory reporting technology company, with 10+ years of experience powering…” Source: RevenueBase Database · checked Sep 21, 2026
17	Infinity Globus, A Springline Company	Partial evidence	Dallas, TX, United StatesHQ checked Sep 21, 2026	201-500	168 contacts →
	Partial evidence “Infinity Globus, a Springline company, is a leading accounting outsourcing firm with over two decades of industry experience, providing tailored taxation and accounting services…” Source: RevenueBase Database · checked Sep 21, 2026
18	Geffen Mesher	Indirect evidence	Portland, OR, United StatesHQ checked Sep 21, 2026	51-200	160 contacts →
	Indirect evidence “We’re a Portland-based accounting firm with a 90+ year legacy, and we’re continuing to grow and evolve every day.” Source: RevenueBase Database · checked Sep 21, 2026
19	Funaro & CO	Indirect evidence	New York, NY, United StatesHQ checked Sep 21, 2026	51-200	146 contacts →
	Indirect evidence “Founded in 1947, Funaro & Co.” Source: RevenueBase Database · checked Sep 21, 2026
20	Mize Cpas INC	Indirect evidence	Topeka, KS, United StatesHQ checked Sep 21, 2026	1,001-5,000	146 contacts →
	Indirect evidence “Mize CPAs is now part of Aprio, a Top 25 premier, full-service business advisory and accounting firm that’s passionate for what’s next.” Source: RevenueBase Database · checked Sep 21, 2026
21	Konnect Books & Taxes- Virtual CFO & USA TAX Consultants	Partial evidence	New York, NY, United StatesHQ checked Sep 21, 2026	51-200	145 contacts →
	Partial evidence “Konnect Books & Taxes, is an International Bookkeeping, Tax & Advisory firm, in the USA, with CPAs & Accountants, ready to help you take care of ALL your numbers.” Source: RevenueBase Database · checked Sep 21, 2026
22	Crosslink Professional TAX Solutions	Partial evidence	Lathrop, CA, United StatesHQ checked Sep 21, 2026	51-200	136 contacts →
	Partial evidence “CrossLink Professional Tax Solutions (CPTS) is a leading provider of professional tax software solutions for professional tax preparers across the United States.” Source: RevenueBase Database · checked Sep 21, 2026
23	Taxwell	Partial evidence	Franklin, NC, United StatesHQ checked Sep 21, 2026	1,001-5,000	136 contacts →
	Partial evidence “Taxwell is a leading digital tax filing platform formed in 2022 from the combination of Drake Software® and TaxAct®.” Source: RevenueBase Database · checked Sep 21, 2026
24	Mcgill, Power, Bell & Associates, LLP	Indirect evidence	Meadville, PA, United StatesHQ checked Sep 21, 2026	51-200	121 contacts →
	Indirect evidence “McGill, Power, Bell & Associates, LLP (“MPB”) is a public accounting firm with five Pennsylvania offices located in the cities of Erie, Franklin, Grove City, Meadville, and…” Source: RevenueBase Database · checked Sep 21, 2026
25	Lavine, Lofgren, Morris & Engelberg, LLP	Indirect evidence	La Jolla, CA, United StatesHQ checked Sep 21, 2026	51-200	118 contacts →
	Indirect evidence “Since 1985, we’ve built a firm where clients receive the highest quality of services, where our people play an important role as they grow professionally and where we as a firm…” Source: RevenueBase Database · checked Sep 21, 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: tax outsourcing companies. 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 tax outsourcing companies.
Partial evidence: Its own public description names part of tax outsourcing companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name tax outsourcing companies. 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 8,199 tax outsourcing companies based in the United States

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Tax outsourcing companies based in the United States at a glance

As of Sep 21, 2026

21.8%Verified-email coverage

13.9Average contacts per company

1-10Median size (employees)

2.4%Largest-city concentration · New York

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

6,333

11-50

1,486

51-200

240

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 8,199 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 tax outsourcing 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.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “tax outsourcing 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 tax outsourcing 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 tax outsourcing companies, 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, 24,785 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 21, 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.

Tax outsourcing companies 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 tax outsourcing 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 tax outsourcing companies are there based in the United States?

RevenueBase identified 8,199 tax outsourcing companies 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?

H&r Block, headquartered in Kansas City, tops this list with the largest team on record.

Which city has the most tax outsourcing companies?

New York leads with 197 headquartered companies, followed by Houston (187) and Miami (98).

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 24,785 verified decision-maker contacts tracked across these 8,199 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 21, 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.