Article 29 outlines the process for the GCC Common Excise Tax Agreement's entry into force. It requires adoption by the GCC Supreme Council and ratification by Member States according to their constitutional procedures. The Agreement officially comes into effect upon the deposit of the second ratification document with the GCC General Secretariat. Crucially, each Member State is mandated to enact a local law to implement the Agreement's provisions, policies, and procedures. A Member State remains outside the scope of the Agreement's implementation until its respective local law becomes effective, ensuring domestic legal frameworks are in place.