Working for companies and business leaders from various sectors of the economy, Niels Vos focuses on company-related criminal law (money laundering, forgery of documents, tax and financial fraud, corruption, market abuse, cybercrime, violations of special criminal legislation, etc.). He assists both defendants and injured parties at all stages of criminal proceedings, whenever possible seeking out-of-court solutions. 

Niels not only has extensive experience in conventional criminal investigations, but also in investigations by, inter alia, the European Public Prosecutor's Office (EPPO), the European Anti-Fraud Office (OLAF), the Financial Services and Markets Authority (FSMA), the Federal Agency for the Safety of the Food Chain (FASFC), the Belgian College of Auditors (CTR/CSR) and the Economic and Social Inspectorate.

Moreover, Niels has expertise in ESG (Environmental, Social & Governance) litigation, with a particular focus on greenwashing. A further focus is on internal investigations where he advises companies on due diligence and compliance programmes.

Between May 2015 and November 2018, Niels was an active member of the Limburg Bar Association. He became a member of the Brussels Bar in November 2018. Since 1 January 2026, he is a partner at Arcas Law.

In addition, Niels has strong ties with the Institute of Criminal Law at KU Leuven as a part-time assistant. He is also a member of the International Association of Young Lawyers (AIJA).