GSTR-3B due date set for monthly returns; file electronically and discharge liabilities via electronic ledgers. The return in FORM GSTR-3B for July to September 2019 must be furnished electronically through the common portal on or before the twentieth day of the month succeeding each month; registered persons must discharge tax, interest, penalty, fees or other amounts payable by debiting the electronic cash ledger or electronic credit ledger, as applicable, not later than that return due date, subject to statutory provisions governing payment.