Sidney Lefèvre began his career at the Brussels Bar in 2002, where he learned the subtleties of corporate, contract and criminal law under the guidance of an experienced lawyer.

In addition to building his own client base, Sidney has put his multilingualism and love of advocacy at the service of several French-speaking law firms, where he has been able to deepen his knowledge in a wide variety of matters.

Since 2009, Sidney has been teaching at INFAC-EFPME, where he is responsible for the private and special security regulation course. Since then, he has been assisting private security companies and private security agents in both private and administrative matters.

In 2010, he joined the team at Sub Rosa Legal, where his experience in criminal law and construction disputes came to strengthen the already existing expertise in business and corporate law.

In 2024, this firm became part of Andersen.