GSTR-3B filing deadline extended for newly migrated taxpayers; prior-period returns must be filed electronically by year-end. Returns in FORM GSTR-3B for the period July 2017 to November 2018 by taxpayers who obtained GSTIN under the specified migration notification shall be furnished electronically through the common portal on or before 31st December 2018, by way of a proviso inserted into the earlier departmental notification.