Robert L. Mahon
- Firmwide Chair, Tax Practice
A leader in state and local tax law, Bob helps clients minimize liabilities and manage compliance challenges.
Bob Mahon helps clients minimize taxes and comply with state and local tax laws. He represents clients in tax audits, refunds, appeals, and litigation. He also offers tax planning and business transaction counsel. Active in the legal community, Bob is the past president of the Tax Section of the Washington State Bar Association and serves as adjunct professor of state and local tax at the University of Washington School of Law, a position he has held for 25 years.
Education & Credentials
Education
- University of Washington School of Law, LL.M., Taxation, 1996
- The University of Iowa College of Law, J.D., with high distinction, 1995
- Grinnell College, B.A., with honors, 1992
Bar and Court Admissions
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Washington
Related Employment
- Bogle & Gates P.L.L.C., Bellevue, WA, Associate, 1996-1999
Professional Recognition
Ranked by Chambers USA as “America’s Leading Lawyer” for Tax, 2023-2024
Listed in Best Lawyers in America: Tax Law, 2012-2024
Named Best Lawyers' Seattle, "Tax Law Lawyer of the Year," 2015, 2018
Listed in Washington Law & Politics, "Washington Rising Stars;" Listed as Super Lawyer, 2023-2024
Impact
Professional Leadership
- Firmwide Chair, Tax, Benefits, & Compensation Practice, 2017-present
- Firmwide Chair, State & Local Tax Practice, 2010-present
- University of Washington School of Law, Adjunct Professor, 1999-present
- Seattle Metropolitan Chamber of Commerce, Board of Trustees, 2018-present
- Washington Department of Revenue Business Advisory Council, 2018-present
- Washington State Bar Association, Tax Section, 1996-present
President, 2008-2009
State & Local Tax Committee Chair, 2004-2008
Legislative Committee Chair, 2010-2015
Executive Committee, 2004-present
- American Bar Association, Tax Section, State and Local Tax Committee, Member, 1996-present
Executive Committee, 2011-present
ABA Sales & Use Tax Deskbook, Editor-in-Chief, 2011-present
Publications Committee, Chair, 2017-present
- Institute for Professional in Taxation, Member, 2018-present
ABA/IPT Advanced Sales/Use Tax Planning Committee, Co-Chair, 2013-present
- Washington Research Council, Board Member, 2018-present
- American College of Tax Counsel, Fellow, 2022
- Journal of Multistate Taxation and Incentives
Editor-in-Chief, 2012-2017
Author, U.S. Supreme Court Update column, 2003-2012
Community Involvement
- City of Seattle, Ethics & Elections Commission, Chair, 2009-2012; Commissioner, 2004-2012
- City of Seattle, Campaign Public Financing Advisory Committee, Member, 2008
- Montlake Community Club, President, 2005-2006; Trustee, 2004-2008
- City of Seattle, Public-Private Partnership Panel, City Council Appointee, 2000-2001
- Northwest Women's Law Center, Legislative Committee, 2000-2006
Insights
News
Professional Experience
State & Local Tax
HomeStreet Inc. v. Washington Department of Revenue
Represented taxpayer in a successful business and occupation tax refund action. 166 Wash. 2d 444, 210 P.3d 297 (2009).
Group Health Cooperative v. City of Seattle
Represented taxpayer in a successful challenge to the application of city business and occupation tax to revenues that were preempted by state and federal law. 146 Wash. App. 80, 189 P.3d 216 (2008).
Community Telecable of Seattle Inc. v. City of Seattle
Represented amicus curiae in support of a successful challenge to the imposition of city utility tax on Internet service. 164 Wash. 2d 35, 186 P.3d 1032 (2008)
City of Seattle v. Visio Corporation
Represented taxpayer in successful administrative appeal of the city's assessment of business and occupation tax on software development activities; represented amicus curiae in opposition to the city's subsequent unsuccessful appeal. 108 Wash. App. 566, 31 P.3d 740 (2001)
Alaska Department of Revenue v. Magella Healthcare Corporation
Represented taxpayer in litigation to obtain alternative income tax apportionment under Alaska's version of Uniform Division of Income Tax Purposes Act (UDITPA) § 18.
Puget Sound Energy Inc. v. Oregon Department of Revenue
Represented taxpayer in litigating and ultimately settling an Oregon property tax dispute.
Tenaska Washington Partners, L.P. v. Washington Department of Revenue
Represented taxpayer in a successful challenge to a public utility tax assessment.
VeriSign Inc. v. Washington Department of Revenue
Represented taxpayer in litigating and ultimately settling a business and occupation tax refund related to the taxation of telecommunications services.
Fresh Express Inc. v. City of Bellevue
Represented taxpayer in litigating and settling a city business and occupation tax refund action.
American Honda Motor Company Inc., Chrysler Motors LLC, and Ford Motor Company v. City of Bremerton
Represented taxpayers in litigating and settling a constitutional challenge to the city's imposition of business and occupation tax on import sales.
Consolidated Food Management Inc. v. Washington Department of Revenue
Represented taxpayer in a successful challenge to retroactive changes in business and occupation tax reporting instructions.
Safeway Inc. v. Takko, et al.
Represented taxpayer in a successful appeal of county personal property tax valuations.
BP Oil Supply Company v. City of Tacoma
Represented taxpayer in a successful nexus challenge to the city's assessment of business and occupation tax.