GSTR-4 filing deadline extended to 31 May, allowing composition taxpayers to furnish the 2020-21 annual return. Amendment inserts a proviso into notification No.57/GST-2 dated 26 April 2019 requiring persons covered thereby to furnish FORM GSTR-4 for the financial year ending 31 March 2021 by 31 May 2021; the amendment is effected under section 148 of the Goods and Services Tax Act, 2017 and is deemed to have come into force on 30 April 2021.