Article 4 identifies the specific persons responsible for paying the imposed Tax. Liability falls upon the Taxable Person making a Taxable Supply or Deemed Supply. For imports, the responsibility lies with the Importer of Concerned Goods. Furthermore, the Article assigns responsibility to the Registrant who acquires goods under the reverse charge mechanism stipulated in Article 48, Clause 3. This clarifies legal liability for tax payment across domestic supplies, imports, and specific hydrocarbon or energy transactions where the recipient accounts for the tax.