Article 1 of the Decree-Law establishes the scope and commencement date for the new tax regime. The provisions of the accompanying law apply to taxable Multinational Entities (MNEs) for all tax periods beginning on or after 1 January 2025. A critical function of this article is to specify which existing tax legislation will be superseded for these MNEs from the effective date. Consequently, Decree No. 3 of 1955, Law No. 23 of 1961, Law No. 46 of 2006, and specific sections of Law No. 19 of 2000 will no longer apply.