Inverted duty refund: concessionally taxed supplies permit refund where output tax is lower than input tax, with stated exceptions. Refund of accumulated input tax credit under the inverted duty clause is admissible where accumulation arises because the rate of tax on outward supplies of the same goods is lower than the rate on inputs at the same point in time due to supply under a government concessional notification, provided other statutory conditions are fulfilled and excluding cases where the output is nil rated, fully exempt, or specifically excluded by government notification.