law: The Integrated Goods and Services Tax Act, 2017
  Chapter III
  Levy and Collection of Tax
  5. Levy and collection.-
  (1) Subject to the provisions of sub-section (2), there shall be levied a tax called the integrated goods and services tax on all inter-State supplies of goods or services or both, except on the supply of alcoholic liquor for human consumption, on the value determined under section 15 of the Central Goods and Services Tax Act and at such rates, not exceeding forty per cent., as may be notified by the Government on the recommendations of the Council and collected in such manner as may be prescribed and shall be paid by the taxable person:
  Provided that the integrated tax on goods imported into India shall be levied and collected in accordance with the provisions of section 3 of the Customs Tariff Act, 1975 (51 of 1975) on the value as determined under the said Act at the point when duties of customs are levied on the said goods under section 12 of the Customs Act, 1962 (52 of 1962).
  (2) The integrated tax on the supply of petroleum crude, high speed diesel, motor spirit (commonly known as petrol), natural gas and aviation turbine fuel shall be levied with effect from such date as may be notified by the Government on the recommendations of the Council.
  (3) The Government may, on the recommendations of the Council, by notification, specify categories of supply of goods or services or both, the tax on which shall be paid on reverse charge basis by the recipient of such goods or services or both and all the provisions of this Act shall apply to such recipient as if he is the person liable for paying the tax in relation to the supply of such goods or services or both.
  1[(4) The Government may, on the recommendations of the Council, by notification, specify a class of registered persons who shall, in respect of supply of specified categories of goods or services or both received from an unregistered supplier, pay the tax on reverse charge basis as the recipient of such supply of goods or services or both, and all the provisions of this Act shall apply to such recipient as if he is the person liable for paying the tax in relation to such supply of goods or services or both.]
  (5) The Government may, on the recommendations of the Council, by notification, specify categories of services, the tax on inter-State supplies of which shall be paid by the electronic commerce operator if such services are supplied through it, and all the provisions of this Act shall apply to such electronic commerce operator as if he is the supplier liable for paying the tax in relation to the supply of such services:
  Provided that where an electronic commerce operator does not have a physical presence in the taxable territory, any person representing such electronic commerce operator for any purpose in the taxable territory shall be liable to pay tax:
  Provided further that where an electronic commerce operator does not have a physical presence in the taxable territory and also does not have a representative in the said territory, such electronic commerce operator shall appoint a person in the taxable territory for the purpose of paying tax and such person shall be liable to pay tax.
  1. Subs. by Act 32 of 2018, s. 3, for sub-section (4) (w.e.f. 1-2-2019).