Place of supply rules for imports and exports determine IGST liability, ITC utilisation hierarchy, and refund eligibility. Imports are treated as supplies to the importer's location in India and attract IGST as inter state supplies, with ITC of IGST available and a prescribed hierarchy for utilising credits (IGST then CGST then SGST) and remaining IGST payable in cash; exports are supplies outside India eligible for refund under zero rating and related refund provisions. Foreign currency invoicing is permitted provided INR conversion rates and INR amounts are shown.