Company lists · Data refreshed September 2026

Top 25 Union compliance law firms based in Washington, United States

Name: Union compliance law 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 29, 2026 136 companies tracked

RevenueBase identified 136 company matches for union compliance law firms associated with Washington, United States as of September 2026 and tracks 8,671 professional contacts across them, including 5,529 with verified work emails. Across the United States, New York is the largest hub for this category (447 companies); Washington has 136.

This list covers company matches for union compliance law 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 29, 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 29, 2026 How this list was built

136Companies

8,671Contacts tracked

5,529Verified emails

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The 25 largest union compliance law firms based in Washington, United States

Ranked by team size

Top 25 of 136 company matches for union compliance law firms based in Washington, United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 29, 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	Arnold & Porter	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	1,001-5,000	2,333 contacts →
	Exact match “Arnold & Porter combines sophisticated regulatory, litigation, and transactional capabilities to resolve clients’ most complex issues.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
2	Venable LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	1,001-5,000	1,790 contacts →
	Exact match “Committed to Your Success – As a law firm of more than 900 professionals, Venable delivers legal services globally in every area of regulatory compliance, government affairs…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
3	Steptoe LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	1,001-5,000	1,207 contacts →
	Exact match “In more than 100 years of practice, Steptoe* has earned an international reputation for vigorous representation of clients before governmental agencies, successful advocacy in…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
4	Wiley Rein LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	501-1,000	576 contacts →
	Exact match “Founded in 1983, Wiley is a dominant presence in the nation’s capital.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
5	Dickstein Shapiro LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	501-1,000	292 contacts →
	Exact match “Dickstein Shapiro LLP, Market Leading Specialty Firm (SM), is internationally recognized for its work with clients, from start-ups to Fortune 500 corporations.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
6	Hausfeld	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	201-500	267 contacts →
	Exact match “Hausfeld successfully resolves disputes for its clients, driven by its bold approach and pioneering experience.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
7	Keller And Heckman LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	230 contacts →
	Exact match “Keller and Heckman, founded in 1962, has a broad practice in the areas of regulatory law, public policy, and litigation, serving both domestic and international clients.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
8	Kellogg, Hansen, Todd, Figel & Frederick Pllc	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	211 contacts →
	Exact match “Kellogg Hansen works in complex trial and appellate litigation.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
9	Groom LAW Group, Chartered	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	174 contacts →
	Exact match “Groom Law Group, Chartered is widely recognized as the leading benefits law firm in the United States with over 90 attorneys dedicated solely to the practice of employee benefits…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
10	Zuckerman Spaeder LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	155 contacts →
	Exact match “Zuckerman Spaeder LLP is consistently recognized as a leading national litigation boutique.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
11	Jackson & Campbell, P.C	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	129 contacts →
	Exact match “For more than 130 years, Jackson & Campbell has been the law firm to which local, regional, and national businesses, associations, and Washingtonians turn for skilled and…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
12	Reno & Cavanaugh, Pllc	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	73 contacts →
	Exact match “Since 1977, Reno & Cavanaugh has been a national law firm dedicated to strengthening communities through strategic use of public and private resources.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
13	HWG LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	70 contacts →
	Exact match “HWG LLP is a boutique law firm designed to offer clients access to top tier legal talent without unnecessary overhead.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
14	Relman Colfax Pllc	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	56 contacts →
	Exact match “Relman Colfax PLLC is a national civil rights law firm, with a litigation practice focused on combating discrimination and obtaining equity, including in the areas of housing…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
15	The Employment LAW Group, P.C	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	55 contacts →
	Exact match “The Employment Law Group® law firm is a litigation boutique concentrating on the representation of employees and whistleblowers.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
16	Bredhoff & Kaiser Pllc	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	49 contacts →
	Exact match “Bredhoff & Kaiser PLLC is one of the nation’s preeminent law firms devoted to empowering workers and the institutions that advocate for them.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
17	Conn Maciel Carey LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	46 contacts →
	Exact match “Conn Maciel Carey LLP is a boutique law firm focused on Labor & Employment, Workplace Safety - OSHA/MSHA, and Litigation.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
18	Katz Banks Kumin LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	42 contacts →
	Exact match “The lawyers of Katz Banks Kumin are nationally recognized leaders in the areas of whistleblower law, discrimination and sexual harassment law, wage and hour law, employment law…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
19	Peacock Keller, LLP	Exact match	Washington, PA, United StatesHQ recorded Sep 29, 2026	51-200	38 contacts →
	Exact match “Peacock Keller is a full service law firm headquartered in Washington, Pennsylvania.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
20	Tiber Hudson LLC	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	36 contacts →
	Exact match “Tiber Hudson LLC is a boutique law firm focused in providing legal services including complex commercial litigation, complex commercial transactions, corporate structure and…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
21	O'donoghue & O'donoghue LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	35 contacts →
	Exact match “O'Donoghue & O'Donoghue LLP is one of the largest and oldest union-side law firms in the United States, with offices in Washington, D.C, Philadelphia, Pennsylvania, and Annapolis…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
22	Federal Practice Group, LLP	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	33 contacts →
	Exact match “Federal Practice Group is a nationally recognized law firm specializing in federal employment, military law, government contracts, security clearance, litigation, and more.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
23	Weiner Brodsky Kider PC	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	31 contacts →
	Exact match “Weiner Brodsky Kider PC is a Washington, D.C-based firm with a national practice focused on compliance, regulatory, transactional and litigation matters related to financial…” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
24	Duncan, Weinberg, Genzer & Pembroke, P.C. Dwgp	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	11-50	28 contacts →
	Exact match “Since its founding in 1971, DWG & P, has provided a broad range of counseling, regulatory, litigation and legislative services to clients in every region of the country.” Recorded in the RevenueBase company graph · Sep 29, 2026 · View company records in RevenueBase
25	Slevin & Hart P.C	Exact match	Washington, DC, United StatesHQ recorded Sep 29, 2026	51-200	26 contacts →
	Exact match “Slevin & Hart, P.C.” Recorded in the RevenueBase company graph · Sep 29, 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 “union compliance law 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 136 union compliance law firms based in Washington, United States

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Union compliance law firms based in Washington, United States at a glance

As of Sep 29, 2026

63.8%Verified-email coverage

63.8Average contacts per company

1-10Median size (employees)

Sep 29, 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 136 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 “union compliance law 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 5,529 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 29, 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.

Union compliance law 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 “union compliance law firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many union compliance law firms are there based in Washington, United States?

RevenueBase identified 136 company matches for union compliance law 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?

Arnold & Porter 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 union compliance law firms?

New York leads the United States with 447 company records, followed by Los Angeles (327) and Chicago (250). Washington has 136.

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 5,529 professional contacts with verified work emails tracked across these 136 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 29, 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.