This Article establishes the mandatory requirement for a Taxable Person to use their Tax Identification Number (TIN). Under the provisions of Article 57 of the Implementing Regulations of the Value Added Tax Law, the TIN must be clearly stated on all Tax Invoices issued. Furthermore, this obligation extends to all correspondence and communication directed to the tax Authority concerning Value Added Tax matters. The purpose of this rule is to ensure consistent and accurate identification of taxpayers, facilitating administrative efficiency and compliance oversight in all VAT-related transactions and procedures.