GSTR-3B filing deadlines require monthly electronic returns by prescribed last dates, with liabilities discharged via e-ledgers. Specification of due dates for submission of returns in Form GSTR-3B for August 2017 through December 2017 requires electronic filing on the common portal by the prescribed last dates. Registered persons furnishing Form GSTR-3B must discharge tax, interest, penalty or other amounts payable under the Act by debiting the electronic cash ledger or electronic credit ledger, as applicable, not later than the prescribed last date, subject to the provisions of section 49.