Jonathan E. Maddison

Jon counsels multinational corporations on a variety of state and local tax issues, particularly the intersection of federal and state law on sales and use tax and income tax. Jon has significant experience with state tax policy and legislation, as well as advising on the constitutionality of proposed legislation and regulations. Jon is a leading expert on issues related to the sharing economy and online marketplace platforms.

Jon also represents clients in state and local tax controversies and litigation matters, from audit to appeal. As a constitutional law adviser, he has filed amicus briefs in the Supreme Court of the United States and the Louisiana Supreme Court on behalf of taxpayer trade associations. His clients include leaders in e-commerce and the digital economy.

Jon is a frequent author and commentator on constitutional law issues and appellate matters in state and local tax. Jon’s recent speaking engagements include the Tax Executives Institute Annual Conference, the Georgetown Advanced Institute of State Taxation, and the Institute for Professionals in Taxation Annual Conference. Recent articles include Platforms: The Finale, 95 TAX NOTES 11 (2020) (coauthored with Professors Walter Hellerstein and John Swain); South Dakota v. Wayfair: The Fall of Quill, the Rise of Economic Nexus, and What Comes Next, IPT Sales and Use Taxation (3ʳᵈ Edition, 2019); and Why Wayfair Won’t Matter, 70 TAX EXECUTIVES 20 (2018). Prior to joining the firm, Jon was an associate with Eversheds Sutherland LLP and Reed Smith LLP.

Education
University of Pennsylvania Law School, 2013, J.D.

Rutgers University, 2010, B.A., summa cum laude

Professional Admissions
Pennsylvania

District of Columbia