Late fee waiver for delayed GSTR-4 returns extends relief where returns filed within a specified reopening period. Waiver of late fee for registered persons who failed to file FORM GSTR-4 for the quarters July 2017 to September 2018 is provided where those returns are furnished between 22nd December, 2018 and 31st March, 2019; the notification is deemed effective from 31st December, 2018.