Article 27 establishes that the implementing Regulations will define the specific time periods, terms, and conditions for the payment of Net Tax by a Taxable Person. The article provides a framework for managing Tax Periods, allowing a Taxable Person to request a change, which is subject to the Authority's approval under conditions stipulated in the Regulations. Furthermore, the Authority is granted the power to compel a Taxable Person to change their Tax Period through a reasoned decision. In such cases, the Authority must notify the Taxable Person of the change in accordance with the timelines and methods specified in the Regulations.