Kay studied law in Cologne and was admitted to the German Bar in Düsseldorf. After his admission he emigrated to South Africa, working as an adviser on German law for LindsayKeller, Attorneys, Rosebank and registered in 1992 as a student of the law faculty with the Randse Afrikaanse Universiteit (as it then was) and graduated in 1996 with a B.Proc. Degree, was admitted as an Attorney in South Africa and became a partner of LindsayKeller. He added a Master of Law in 2002 and a Diploma in Insolvency Law in 2003. In 2007 he obtained a Higher Certificate in Mediation, Arbitration and ADR. He is advising the German Embassy in law and is the Attorney of Trust of the Embassy of Austria.
He left LindsayKeller Attorneys in March 2012 and founded his own specialised commercial law firm, WerthSchröder Inc., of which he is since the Senior Partner. He is also a partner of the German law firm “Gloria & Rosenstein”. He has chaired the board of the German International School for 5 years from 2006 to 2011, is a member of the Senior Council of the German Southern African Chamber of Commerce since 2012, a member of boards of companies and trusts and the Chairman of the Board of Trustees of the Deutsche Industrie Fond. He has been director of the European Chamber since 2017.