Dr. Simon Whitehead practiced as a litigation lawyer in private practice for 37 years in the UK and Australia.  For over 25 years his work mostly involved EU law challenges to national direct tax provisions and fiscal state aid matters.  He is best known for representing the taxpayers in C-446/03 Marks & Spencer (Group Relief), C-524/04 Test Claimants in the Thin Capitalisation Group Litigation and C-446/04, 35/11 & 362/12 Test Claimants in the Franked Investment Income Group Litigation.  He represented taxpayers in the UK Supreme Court 10 times and advised in cases before the Danish and Swedish Supreme Courts.  Between 2003 and 2021 he represented taxpayers before the Court of Justice of the EU 8 times.  He set up and was selected as the managing and test case solicitor for the 6 major direct tax group litigation orders (GLOs) in the UK on EU tax issues. 

He was a founding partner of the litigation firm, Joseph Hage Aaronson, in 2013.  Until he retired from practice in January 2025 he had been listed for 20 years as a “Band 1” tax litigator by both Chambers & Partners and the Legal 500.  He is also a Visiting Expert Fellow at the Copenhagen Business School.  He has written extensively on areas of EU law and is currently contributing to the next edition of Farmer & Lyal, EU Tax Law (Clarendon Press). Simon has a LLB, BA (1^st Class) and PhD in Classics and Ancient History from the University of Sydney.