Extension of GSTR-3B filing deadline requires newly migrated taxpayers to file returns electronically by notified deadline. Taxpayers who obtained GSTIN under the August 2018 migration notification must furnish FORM GSTR-3B for the period July 2017 to November 2018 electronically through the common portal by the extended deadline, effected by insertion of a proviso into the first paragraph of the two principal notifications amending their filing obligations.