Léon studied criminal law and tax law in Utrecht and Rotterdam. He has been a lawyer and tax consultant since 2005 prior to which he was a tax consultant in the international consultancy practice.
His practice operates at the intersection of the prevention of litigation and providing representation during legal proceedings. Usually this involves complex cases which require knowledge of numerous areas of expertise and means that he has to operate on multiple levels. With his strategic insight and knowledge about civil, criminal and procedural administrative law, Léon is able to combine his financial and fiscal expertise in the cases he handles. As a lawyer he is specialised in cases that lie in the field of fiscal criminal law (FIOD cases and related offences such as forgery of documents, money laundering, bankruptcy fraud and property fraud), the right of recovery (writs of execution, attachments, setoffs, liability claims), fiscal proceedings and civil proceedings involving fiscal aspects. Léon has a special interest in assisting with requests for international information exchange, whether of a criminal or fiscal nature. He also has expertise and experience in providing assistance in connection with compliance and setting up internal investigations. He provides legal assistance to companies, directors, shareholders and employees as well as to trust offices, accountants and tax consultants (and their employees).
Léon is a board member of the Dutch Tax Lawyers Association (NVAB), a member of the Dutch Association of Criminal Defence Lawyers (NVSA), a member of the Environment Law Association (VMR), a member of the Administrative Law Association (VAR) and a member of the fiscal studies association, Vereniging voor Belastingwetenschap.
As an author, he writes the commentary to Articles 26 and 27 of the OECD Model Tax Convention on Income and Capital with regard to international information exchange and international collection.