We are Grant Thornton

Orange County, California

  • Life sciences
  • Manufacturing, Transportation & Distribution
  • Technology, media & telecommunications
  • Energy
Service Experience
  • Tax

David Zaiken




Executive summary 


David has over 40 years international tax experience advising clients on a global basis and is currently a senior member of Grant Thornton's California offices. Prior to that David was a core member of Washington National Tax Office specializing in international tax. Prior to joining Grant Thornton, David was the Associate Vice President of International Tax Planning at Weatherford (a large oil field services company).


David has been deeply involved in Entertainment & Media, High Tech, Life Science, and Manufacturing industries throughout his career. David has been part of numerous international tax planning and controversies throughout his career that involved both corporate and transfer pricing matters and has helped clients manage the changing geography of global tax planning under tax reform in both the U. S. and under Base Erosion and Profit Shifting (BEPS).


David is a core international tax committee member of the United States Council of International Business and participates in commenting on various OECD and other matters. David has core industry experience in energy, high-tech, pharmaceuticals, intellectual property, and manufacturing.


Prior to joining Grant Thornton, David held positions as an international tax partner of Arthur Andersen, KPMG, and Alvarez & Marsal. David is a CPA and a member of the AICPA and has been an author and a lecturer at tax events.



Professional qualification

  • AICPA and California State Society of CPAs


Presentations and Publications

  • Author in Tax Advisor on Tax Reform, Numerous Presentations on International Tax



  • David has a BBA from the University of Iowa and a MPA in taxation from the University of Texas at Austin.

Search for people at Grant Thornton


Enter a name and/or keywords such as service area, industry or location to get to know our business leaders — partner, principal or managing director. We look forward to hearing from you.