Clause 18 of the Bill provides for the following:
(1) An additional tax on supply of goods, not exceeding one per cent. in the course of inter-State trade or commerce shall, notwithstanding anything contained in clause (1) of Article 269A, be levied and collected by the Government of India for a period of two years or such other period as the Goods and Services Tax Council may recommend, and such tax shall be assigned to the States in the manner provided in clause (2).
(2) The net proceeds of additional tax on supply of goods in any financial year, except the proceeds attributable to the Union territories, shall not form part of the Consolidated Fund of India and be deemed to have been assigned to the States from where the supply originates.
(3) The Government of India may, where it considers necessary in the public interest, exempt such goods from the levy of tax under clause (1).
(4) Parliament may, by law, formulate the principles for determining the place of origin from where supply of goods take place in the course of inter-State trade or commerce.