Refund under GST: procedural conditions, time limits and provisional payments for input tax credit and zero-rated supplies. Refund under GST covers balances in the electronic cash ledger, and unutilized input tax credit arising from zero-rated supplies or where input tax rates exceed output rates, subject to statutory exclusions and procedural claim, acknowledgement, and sanction requirements under section 54 and associated rules; provisional refunds for eligible zero-rated supplies may be granted before full verification, and refunds may be withheld or adjusted to recover unpaid tax, interest or penalties.