Return filing requirement: extension to furnish FORM GSTR-4 for the 2020-21 year, now due by the notified deadline. Amendment requires specified persons to furnish returns in FORM GSTR-4 for the financial year ending 31 March 2021 by 31 May 2021, introduced by inserting a proviso into the earlier notification. The notification is issued under statutory authority and is declared to be deemed to have come into force from 30 April 2021.