Parliament to formulate principles for determining place of supply of goods :
Parliament may, by law, formulate principles for determining (a) place of supply of goods or services (b) when supply of goods or services or both are in the course of inter-State trade or commerce -Article 269A(2) of Constitution of India inserted w.e.f. 16-9-2016.
The provisions relating to Place of Supply are made under these powers. That is the reason why these provisions are contained in IGST Act and not CGST Act.