A notary in Marseille, Decorps is Chairman of the International Union of Notaries (UINL).

He has been Vice Chairman of the High Council of Notaries and then its Chairman from 1998 to 2000.

He has then successively held the Chairmanship of the Commission of European Affairs (UINL) (2002-2004), the Association of French Notaries (2002-2006) and the Commission of International Notarial Cooperation (CCNI) of the UINL since 2000.

Architect of the judicial cooperation between France and China, Decorps is Chairman of the Center of Training and Notarial and Judicial Exchanges in Shanghai.

In addition, he has been associate Professor at the Faculty of Law of Aix-en-Provence since 2000.