Article 80 stipulates that the Law will be published in the Official Gazette and enters into force 90 days thereafter. It applies to taxable years beginning after its effective date; years starting on or before this date are governed by prior laws. The Article explicitly repeals several key pieces of previous legislation, including the Income Tax Law (Royal Decree No. 3321), the Additional Income Tax on Oil and Hydrocarbons Law (Royal Decree No. 7634), and the Natural Gas Investment Tax Law (Royal Decree No. M/37). A specific provision states that the tax withholding rules outlined in Article 68 become effective immediately from the Law's entry into force.