Short answer: monthly filers file GSTR-1 by the 11th and GSTR-3B by the 20th of the next month. Quarterly (QRMP) filers file GSTR-3B by the 22nd or 24th of the month after the quarter, depending on their state. Composition dealers file CMP-08 by the 18th after each quarter. The annual GSTR-9 is due by 31 December.
Dates can be extended by government notification. Always confirm on the GST portal or with your CA.
Monthly filers
- GSTR-1 (sales / outward supplies): 11th of the following month.
- GSTR-3B (summary return and tax payment): 20th of the following month.
Quarterly filers (QRMP scheme)
- GSTR-3B: 22nd or 24th of the month after the quarter ends, depending on your state of registration.
Composition scheme
- CMP-08 (quarterly statement and tax payment): 18th of the month after the quarter.
Annual return
- GSTR-9: 31 December after the financial year ends, for businesses it applies to (FY 2025-26 → 31 December 2026).
Before you file: two quick checks
Most filing problems start on the invoice. Check that every buyer GSTIN is valid (the last character is a check digit that catches typos), and that invoice numbers are unique for the year and no longer than 16 characters.
Reveaxa’s GST tools give you a due-date calendar, a GSTIN checker and a monthly export for your CA. They help you prepare; they don’t file on your behalf.
Reveaxa guide reference: RVX-B-gst-due-dates-2026-27