Tax classification error: refund of wrongly paid central or state tax allowed when supply reclassified across state lines. Where a registered person paid Central Tax and State Tax treating a transaction as an intra State supply but it is later held to be an inter State supply, the taxes so paid are refundable in the prescribed manner and subject to prescribed conditions; if integrated tax was paid treating a transaction as inter State but it is later held to be intra State, no interest is payable on the State Tax amount.