The Bureau International de Métrologie Légale (BIML) is the Secretariat and Headquarters of the OIML, ensuring the day to day running of activities and the planning of longer term actions.

It coordinates and informs CIML Members of technical work undertaken by OIML Technical Committees (of which there are currently eighteen), organizes OIML Conference and Committee Meetings, and manages the finances of the Organization.

Liaisons are maintained with Regional, International and National Organisms; these ties are becoming increasingly close, which serves to further legal metrology in a wider context.

Another key aspect of BIML work is the issuing of OIML Publications (Recommendations, Documents, Vocabularies, and the quarterly Bulletin) and also the maintenance of the Web Site.