Fraud-based tax determination: notice, interest and penalty provisions require payment or prosecution under GST recovery framework. Determination of tax not paid, short paid, erroneously refunded or input tax credit wrongly availed by reason of fraud or wilful misstatement or suppression triggers a statutory notice requiring payment of the tax, interest and a penalty equal to the tax; the officer may issue supplementary statements treated as notices where grounds (other than fraud) coincide. Voluntary pre notice payment with interest and a reduced penalty can halt initiation, specified payments after notice or order conclude proceedings, and the officer must determine amounts by order within a five year limitation; 'suppression' means non declaration or failure to furnish required information.