Goods and services tax on inter State supplies: Union to levy and apportion tax under Parliament's law on place of supply. Goods and services tax on supplies in the course of inter State trade or commerce shall be levied and collected by the Union and apportioned between the Union and the States as Parliament may provide, with supplies in the course of import deemed to be inter State supplies. Parliament may, by law, formulate principles for determining the place of supply and when a supply occurs in the course of inter State trade or commerce.