Unutilized input tax credit allowed as refund for zero-rated supplies or rate-mismatch, subject to export-duty and drawback bars. Unutilized Input Tax Credit may be refunded where zero rated supplies are made without payment of tax, or where credit accumulates because input tax rates exceed output tax rates (other than for nil-rated or fully exempt supplies). Refunds are not allowed where exported goods attract export duty, or where the supplier has availed drawback for central tax or claimed refund of integrated tax on such supplies.