Section 74(1) in The Central Goods and Services Tax Act, 2017
(1)Where it appears to the proper officer that any tax has not been paid or short paid or erroneously refunded or where input tax credit has been wrongly availed or utilised by reason of fraud, or any wilful-misstatement or suppression of facts to evade tax, he shall serve notice on the person chargeable with tax which has not been so paid or which has been so short paid or to whom the refund has erroneously been made, or who has wrongly availed or utilised input tax credit, requiring him to show cause as to why he should not pay the amount specified in the notice along with interest payable thereon under section 50 and a penalty equivalent to the tax specified in the notice.
