Late fee waiver for late GSTR-4 filers who submit returns within prescribed extended window period. The amendment to Notification No. 73/2017-State Tax provides that the amount of late fee payable under the Act shall be waived for registered persons who failed to furnish returns in FORM GSTR-4 for the quarters from July 2017 to September 2018 by the due date but who furnish those returns between 22nd December 2018 and 31st March 2019.