Concessional IGST applies to inter state supplies for export subject to documentary, movement and warehouse conditions. IGST is concessional for inter State supplies to a registered recipient for export: integrated tax exceeding the concessional rate is exempt subject to conditions. Key operative requirements include issuance of a tax invoice by the supplier; export within the prescribed time limit; recording the supplier's GSTIN and tax invoice number in the shipping bill; recipient registration with an Export Promotion Council or Commodity Board; placement of a concession order with copy to the supplier's tax officer; prescribed movement of goods to port or registered warehouse; aggregation and warehouse endorsement procedures where applicable; and post export provision of shipping bill and proof of export to the supplier and its jurisdictional tax officer.