Léon studied criminal law and tax law in Utrecht and Rotterdam. He has been an attorney and tax consultant since 2005. Before that, he was a tax adviser in international consultancy. As an attorney, he completed inter alia the Specialist Course in Criminal Law. This post-graduate course deals with the broad spectrum of procedural and substantive criminal law, as well as their international (European) and ECHR aspects.
Léon has a broad practice in sanctions law where he is mainly involved in:
One element of his practice is the emphasis on preventing proceedings and finding practical solutions for his clients in the knowledge that litigation is not always the best solution.
Léon is a board member of the professional association of attorneys and tax consultants (NVAB). He is also a member of various professional associations in areas including criminal law, administrative law and tax law.
He is the author of the commentary on Article 27 of the OECD Model Tax Convention on the international collection of taxes.