Zero rated supply rules permit input tax credit and refund mechanisms for exports and SEZ supplies under prescribed safeguards. Section 16 defines zero rated supply as exports and authorised supplies to Special Economic Zone developers or units and confirms that input tax credit may be availed for such supplies notwithstanding any exempt status, subject to section 17(5) CGST. Registered persons may claim refund of unutilised input tax credit without payment of integrated tax when supplying under bond or Letter of Undertaking, and the Government may notify classes allowed to pay integrated tax and claim refunds; refunds are barred where zero rated goods are subject to export duty.