Article 10 establishes the administrative obligations for all taxpayers engaging in business or earning taxable income in Qatar. They are required to register with the General Tax Authority, obtain a unique tax number, and promptly notify the Authority of any changes affecting their tax status. These procedural steps are foundational for the tax administration's oversight. Failure to comply with these registration and notification requirements triggers financial penalties, as the Law prioritizes the accurate identification and tracking of all taxable entities within the jurisdiction.