GST Filing Deadlines You Cannot Afford to Miss in FY 2026-27

Late GST filing doesn't just mean a late fee — it can freeze your e-way bill generation and, if it drags on, your GSTIN itself. Here's the calendar every registered business should have pinned up.

GSTR-1, the outward supplies return, is due on the 11th of the following month for monthly filers, or the 13th of the month after quarter-end for those on the QRMP scheme. GSTR-3B, the summary return where you actually pay tax, is due on the 20th for monthly filers — staggered to the 22nd or 24th for QRMP filers depending on your state.

Annual return GSTR-9 is due by December 31st following the financial year, and it's mandatory once turnover crosses ₹2 crore. If your turnover is above ₹5 crore, you also owe a reconciliation statement, GSTR-9C.

Our advice to every client: don't wait for the reminder SMS. Reconcile purchase invoices against your GSTR-2B monthly, not at year-end — most of the notices we help clients respond to trace back to a mismatch that was invisible for eleven months and obvious in the twelfth.