Professional Cards (Self-Employed)
Self-employed professionals from outside the EU must apply for a professional card (carte professionale/beroepskaart) in order to work in Belgium. A professional card can be issued for a period of five years. You'll need a passport, medical certificate and a police certificate in addition to proof of your qualifications in your profession. Be sure to check with a Belgian embassy or consulate in your home country, as some professions require specific proof that you're already established in your field.
The renewal of Professional Cards does not usually pose any problems.