GST on advances: tax liability arises on receipt of advance and must be discharged with prescribed vouchers and returns. Advances received for future supplies are taxable at the time of receipt to the extent of the advance; suppliers of services must pay GST on such advances on receipt, while many goods suppliers (non composition) were exempted by notification so their time of supply arises on issuance of invoice. If rate or place of supply is indeterminable at receipt, tax is payable at 18% and treated as inter State. Receipt vouchers, separate advance accounts, reporting in return tables and appropriate refund vouchers or credit notes are required for subsequent adjustments.