Taxability of diplomatic purchases: taxable at sale, recoverable through GST refund subject to prescribed filing rules. Purchases by diplomatic missions and UN bodies are taxable and recoverable only through refund; refunds must be claimed under the CGST/SGST refund rules within the prescribed time limit from the last day of the month in which the supply was received. Missions and UN bodies must obtain a Unique Identity Number and purchases must be reported by suppliers against that number in their outward supplies returns.