Article 13 of the GCC Common Excise Tax Agreement establishes the mandatory requirement for tax registration. It stipulates that any individual or entity officially designated by a Member State's Tax Administration as a 'Person Obliged to Pay Tax' must register for excise tax purposes. This provision is fundamental to the compliance framework, ensuring that all liable parties are formally recorded within the tax system. The article specifies that the registration process itself must be conducted in accordance with the detailed provisions and procedures laid out in Article 7 of this Agreement, thereby linking the obligation to register with its procedural requirements.