GST return filing calendar, edit facility for GSTR-3B corrections, monthly/quarterly filing options and reduced late fees. All registered persons must file FORM GSTR-3B monthly; FORM GSTR-1 filing periodicity depends on self-assessed aggregate turnover ( Rs.1.5 crore may file quarterly, otherwise monthly), with an election for monthly filing binding for the financial year. Late fees for October onwards are reduced to Rs.20/day for nil-liability returns and Rs.50/day otherwise. An edit facility permits amendment of FORM GSTR-3B before offsetting; thereafter corrections must be made in subsequent returns, amended in FORM GSTR-1 where applicable, or reclaimed by refund. System reconciliation with GSTR-1/GSTR-2 will be operationalised later.