Company lists · Data refreshed September 2026

Top 25 Professional services firms based in Washington, United States

Name: Professional services firms based in Washington, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 5, 2026 138 companies tracked

RevenueBase identified 138 company matches for professional services firms associated with Washington, United States as of September 2026 and tracks 1,106 professional contacts across them, including 282 with verified work emails. Across the United States, New York is the largest hub for this category (620 companies); Washington has 138.

This list covers company matches for professional services firms associated with Washington, 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 5, 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 5, 2026 How this list was built

138Companies

1,106Contacts tracked

282Verified emails

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The 25 largest professional services firms based in Washington, United States

Ranked by team size

Top 25 of 138 company matches for professional services firms based in Washington, United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 5, 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.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	IBM Promontory	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	501-1,000	403 contacts →
	Exact match “IBM Promontory is a global leader in strategy, risk management, and compliance consulting.#IBMConsulting” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
2	Raffa, PC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	1,001-5,000	87 contacts →
	Exact match “Top accounting firm Raffa, P.C.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
3	HAN Group LLC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	51-200	51 contacts →
	Exact match “Han Group is a public accounting firm committed to serving the nonprofit community by providing unparalleled expertise in nonprofit Audits & Assurance, Managed Accounting, Tax…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
4	Iuvo Systems	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	36 contacts →
	Exact match “At Iuvo Systems Inc, we empower government contractors and federal agencies to succeed by delivering specialized accounting, compliance, and business solutions tailored to the…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
5	Bazilio Cobb Associates	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	201-500	28 contacts →
	Exact match “Since our founding in 1983, Bazilio Cobb Associates has provided professional services to federal, state, and local government agencies; Fortune 500 companies; nonprofit…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
6	IBS Management & Consultancy Services	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	51-200	21 contacts →
	Exact match “IBS is an Accounting, Finance, Management, and Transaction Advisory consulting firm.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
7	Quatt Associates	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	19 contacts →
	Exact match “Quatt Associates, Inc.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
8	Panda Accounting	Exact match	Washington, UT, United StatesHQ recorded Sep 5, 2026	51-200	19 contacts →
	Exact match Recorded description not available. Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
9	Rosemckenna, Pllc	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	17 contacts →
	Exact match “RoseMcKenna PLLC is a boutique accounting firm dedicated to providing the absolute best in personalized and professional tax services.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
10	CWP Consulting INC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	16 contacts →
	Exact match “CWP Consulting was built around the desire to provide quality, professional services to individuals and business owners through the use of specialized and individualized services.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
11	The Kenrich Group LLC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	51-200	14 contacts →
	Exact match “The Kenrich Group, an HKA Company, is a business and litigation consulting firm with 50 offices in 19 countries.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
12	CFO Services Group	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	1-10	12 contacts →
	Exact match “CFO Services Group is your dedicated accounting team and much more.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
13	Seiler, Singleton & Associates, PA	Exact match	Washington, NC, United StatesHQ recorded Sep 5, 2026	1-10	9 contacts →
	Exact match “At Seiler, Singleton & Associates, P.A, our goal is to offer quality accounting, tax, payroll, and advisory services to individuals, small businesses, and nonprofit organizations.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
14	Aa&t Group	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	1-10	9 contacts →
	Exact match “We provide value to our clients, empowering them to succeed.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
15	Phillips, Salmi Associates, LLC	Exact match	Washington, IL, United StatesHQ recorded Sep 5, 2026	1-10	8 contacts →
	Exact match “Background Phillips, Salmi + Associates, LLC is a certified public accounting firm with locations in Washington and Springfield, Illinois.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
16	O Riordan Bethel LAW Firm, LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	7 contacts →
	Exact match “Nationally-recognized and award-winning economists, lawyers and public policy experts providing public policy analysis; business process improvement; research and analysis…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
17	Gray Global Advisors, LLC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	1-10	7 contacts →
	Exact match “Gray Global Advisors is a full-service advisory firm that provides innovative industry focused strategic development and implementation services.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
18	Helfer And Company, LLC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	1-10	7 contacts →
	Exact match “For over three decades, Alan S.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
19	Accounting 4 DC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	1-10	7 contacts →
	Exact match “At Accounting 4 DC, our goal is to help our clients run healthy, profitable businesses.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
20	Leftwich LLC	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	7 contacts →
	Exact match “Leftwich LLC is a multi-disciplinary legal and consulting firm.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
21	Credibility International, An HKA Company	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	6 contacts →
	Exact match “Our professionals have focused our careers upon becoming functionally excellent in the fields of accounting and finance.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
22	Allenmitchell, LLP Cpas & Consultants	Exact match	Washington, IA, United StatesHQ recorded Sep 5, 2026	1-10	5 contacts →
	Exact match “At AllenMitchell, our goal is to provide the top shelf service that you've come to expect at larger national and regional firms but in a more relaxed environment and at a price…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
23	Morgan Wingate & Co, P.C	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	5 contacts →
	Exact match “Welcome to the firm of” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
24	Franklin & Turner	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	51-200	5 contacts →
	Exact match “Hamilton Enterprises, LLC, is an assurance and advisory company that provides professional services to clients.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
25	Consultvisory	Exact match	Washington, DC, United StatesHQ recorded Sep 5, 2026	11-50	5 contacts →
	Exact match “At ConsultVisory, we specialize in navigating the intricate landscape of Regulatory Compliance, Finance & Accounting Services, Strategic Marketing, Information & Technology…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “professional services firms”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 138 professional services firms based in Washington, United States

See the full list, filter by size, metro and specialty, and access 282 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Professional services firms based in Washington, United States at a glance

As of Sep 5, 2026

25.5%Verified-email coverage

8.0Average contacts per company

1-10Median size (employees)

Sep 5, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

Email recency for this list is measured across the whole United States list rather than for Washington, so it is reported there. Company counts and contact totals on this page are exact for Washington, over 138 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 Washington, United States whose business descriptions match “professional services 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 282 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 5, 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.

Professional services firms by metro in the United States

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 “professional services firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many professional services firms are there based in Washington, United States?

RevenueBase identified 138 company matches for professional services firms associated with Washington, 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?

IBM Promontory tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city in the United States has the most professional services firms?

New York leads the United States with 620 company records, followed by Houston (420) and Atlanta (304). Washington has 138.

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 282 professional contacts with verified work emails tracked across these 138 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 5, 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.