Article 67 establishes the mandatory timeframe for issuing a Tax Invoice. A Registrant is required to issue the invoice within 14 days from the date of supply, as specified in either Article 25 or Article 26 of the Decree-Law. This provision, amended by Federal Decree-Law No. 18 of 2022, also grants flexibility. It stipulates that the Executive Regulation of the Decree-Law may define specific cases that are subject to different time periods or that necessitate the immediate issuance of a Tax Invoice, in accordance with the controls detailed within those regulations.