Pat Derdenger

Pat Derdenger

Partner vCard
602.734.3815 fax
201 East Washington Street
Suite 1200
Phoenix, AZ 85004

Clients rely on Pat Derdenger for his deep knowledge of state and local tax issues that vitally impact business operations. Serving businesses across industry sectors, Pat understands how to evaluate complex transactions, applying the latest laws and regulations toward obtaining tax benefits and incentives, while reducing tax exposure.

In his extensive state and local tax practice, Pat advises businesses on corporate and individual income, multi-state sales and use, and property tax matters, and counsels them on the state and local tax implications of their business transactions. He also represents clients in related litigation matters, from audits and appeals through various administrative states, as well as in federal and state courts and courts of appeals, and the US Tax Court. He has obtained private tax rulings for clients on state and local tax issues and helped draft state tax legislation for clients and industry groups. Pat also advises businesses on the tax implications of various economic incentives and benefits of relocating to and operating in Arizona. In addition, he frequently represents construction industry and homebuilder clients on tax issues related to maintenance, repair, replacement, alteration (MRRA) and modification projects in Arizona.

Pat also counsels clients on federal income and employment tax matters, independent contractor/employee tax issues, responsible officer penalties, information return filing penalties, and federal and state excise taxes, and represents them in related litigation matters. Clients also turn to him for advice on constitutional issues, including the federal commerce clause, due process clause, and equal protection clause.

Memberships & Affiliations

  • National Tax Association
  • Arizona Tax Research Association, Board of Directors and Tax Practitioners' Committee Member
  • Arizona Chamber of Commerce and Industry, Tax Committee
  • National Association of Property Tax Attorneys, Board of Directors
  • Institute for Professionals in Taxation (IPT)
  • American Bar Association, State and Local Tax Committee, Section of Taxation
  • Arizona State Bar, Tax Section (Prior Chair)
  • Council on State Taxation

Related News


Pat is a frequent lecturer on state and local tax subjects for various professional audiences and continuing education programs, and also coordinates the Annual Construction Sales Tax Conference for contractors, homebuilders and developers.

  • Speaker, “The Changing Sales Tax Landscape – What’s Ahead After Wayfair?” - Lorman Seminars, August 9, 2018, October 3, 2018, April 3, 2019
  • Speaker, “Taxation of Privately-Owned Property Located on Native American Reservations – Is it or Isn’t It Taxable?” - ABA/IPT Advanced Property Tax Seminar, March 14-15, 2019
  • Speaker, “Annual Sales/Property & Unclaimed & Unclaimed Property Tax Update,” Phoenix Tax Workshop, Arizona Society of CPAs, February 16, 2019
  • Speaker, "The Changing Sales Tax Landscape – What’s Ahead After Wayfair?” - Tax Executives Institute (TEI) State Tax Day, September 26, 2018
  • Speaker, "The City Speculative Builder Tax: A Hidden Land Transfer Tax?" - State Bar of Arizona Tax Section Program - Specialization Credit, January 22, 2019
  • Speaker, “Changes in the Internet Sales Tax Landscape,” Arizona Association of Accounting and Tax Professionals, October 24, 2018
  • Speaker, "A Hidden Land Transfer Tax," ASCPA Phoenix Tax Workshop, October 20, 2018
  • Speaker, "Finding Your Way After Wayfair: Navigating 'Economic Nexus' and Internet Sales Taxation," ALI CLE, August 8, 2018
  • Speaker, "Sales Taxation of Internet Transactions: What Now after Wayfair?," Lorman Seminars, July 30, 2018
  • Speaker, "Sales and Use Tax Issues of Internet Transactions," Lorman Seminars, April 24, 2018
  • Speaker, "Recent Sales and Income Tax Highlights (The Interesting 'Stuff')," Arizona Tax Conference, August 31, 2017
  • Speaker, "Arizona Sales/Property and Unclaimed Property Tax Update," ASCPA, February 18, 2017
  • Speaker, "Arizona Unclaimed Property Reporting," Lorman Seminars, November 11, 2016
  • Speaker, "Sales and Use Tax Issues of Internet Transactions," Lorman Seminars, October 27, 2016
  • Speaker, "Simplified Sales Tax - Where We Are in the Process," ASCPA, October 22, 2016
  • Speaker, "Sales and Use Tax Issues of Internet Transactions," Lorman Seminars, April 28, 2016
  • Speaker, "Annual Sales and Use Tax/Personal Property Tax/Unclaimed Property Update," ASCPA, February 20, 2016
  • Speaker, "Arizona Tax Update," Tax Executives Institute, September 17, 2015
  • Speaker, "Sales and Use Tax Issues of Internet Transactions," Lorman Seminars, April 1, 2015


  • Best Lawyers in America - Tax Law; Litigation and Controversy: Tax, 1995-2020
  • Southwest Super Lawyers - Tax, 2007-2019
  • AZ Business Leaders - Law: Tax, 2015-2019
  • Legal 500 - U.S., Tax: U.S. Taxes, Contentious, 2018
  • Arizona State Bar - Henry Tom Outstanding Tax Attorney, 2017
  • Best Lawyers in America - Lawyer of the Year - Tax Law: Phoenix, 2016
  • Best Lawyers in America - Lawyer of the Year - Tax Litigation and Controversy Law: Phoenix, 2015
  • Legal 500 - U.S., Tax: Domestic Tax, 2012-2015
  • AZ Business Magazine - Arizona's Top Lawyers: Tax, 2010, 2013-2014
  • Ranking Arizona - Top Lawyers: Tax, 2013
  • Southwest Super Lawyers - Top 50 Attorneys - Arizona, 2013
  • Legal 500 - U.S., Tax: Controversy, 2011-2012
  • Arizona’s Finest Lawyers, 2011
  • Southwest Super Lawyers - Top 100 Attorneys - Arizona, 2009
  • Strafford Publications - Advisory Board, Sales and Use Tax Alert

Other Info


LL.M., George Washington University Law School, 1977, Taxation
J.D., University of Southern California, Gould School of Law, 1974
M.B.A., University of Southern California, 1971

Bar Admissions

Arizona, 1979
California, 1974