Article 18 mandates the appointment of a 'Filing Constituent Entity' for every MNE Group or Joint Venture operating in Bahrain. This designated entity holds primary responsibility for all administrative tax matters, including registration, submitting tax returns, making elections (such as safe harbour or substance-based exclusions), and paying the Tax Due. The appointment is finalised by notifying the National Bureau for Revenue via a specific form. This centralised responsibility ensures that the Bureau has a single point of contact for the group's obligations under Decree-Law No. 11 of 2024, streamlining communication and compliance for large multinational structures.