To operate a hotel or to offer a dwelling or room on a booking website, you need to be registered with Brussels Economy and Employment and meet certain conditions.
How do you do that? Consult the Brussels Economy and Employment website.
Are you the owner of a tourist accommodation (e.g. a hotel, a campsite or a guest house) in the Brussels-Capital Region? If so, you must register and submit a monthly regional tax return for tourist accommodation facilities. For more information, visit the Brussels Taxation website.