GST return deadline extension for GSTR-3B: staggered electronic filing dates based on turnover and principal place of business. Amends Notification No. 29/2020 to prescribe staggered electronic filing deadlines for GSTR-3B for May 2020: taxpayers above a specified aggregate turnover must furnish GSTR-3B through the common portal by an earlier deadline, while taxpayers up to that turnover are divided into two groups by principal place of business and assigned two later electronic filing deadlines respectively; amendment relies on section 168 of the CGST Act and sub-rule (5) of rule 61 of the CGST Rules.