Stephan is a partner of Oppenhoff. In 1996 he was a Foreign Associate with Lovells in London. From 2001 to 2007 he was a partner at Oppenhoff & Rädler / Linklaters LLP. He studied law at the University of Bonn.
In 2014, he has been elected as Vice-Chair of the International Sales Subcommittee on Export Controls, Sanctions and Anti-Corruption of the International Bar Association (IBA).