Supply reclassification prompts tax refunds where intra to inter State change or interest relief where inter to intra State change. If central tax and State tax were paid treating a transaction as intra State but later held inter State, the amounts so paid are refundable as prescribed; if integrated tax was paid treating a transaction as inter State but later held intra State, no interest is payable on the State tax amount that becomes payable due to reclassification.