Most GST penalties aren't about getting the numbers wrong — they're about filing late. The rules themselves are fairly predictable once you know the pattern, so here's the plain version.
GSTR-1 (outward supplies)
This return reports your sales. If you're on monthly filing, it's due by the 11th of the following month. If you've opted into the QRMP scheme (quarterly filing with monthly payment), you file quarterly instead, with a monthly IFF (Invoice Furnishing Facility) option in between for buyers who need timely credit.
GSTR-3B (summary return and tax payment)
This is where you actually pay the tax due. Monthly filers are typically due by the 20th of the following month; QRMP filers get staggered dates around the 22nd or 24th depending on their state. This is the return most closely tied to late fees and interest, since it's where the payment happens.
GSTR-9 (annual return)
A yearly reconciliation covering the whole financial year, generally due by the 31st of December following the year-end — though this has been extended in past years, so it's worth confirming the current deadline rather than assuming.
What actually happens if you miss one
- A late fee accrues per day of delay, separately for CGST and SGST.
- Interest applies on any tax paid late, calculated from the original due date.
- Your GSTR-1 filing can get blocked if GSTR-3B for the previous period hasn't been filed — so one missed return can cascade into a filing freeze.
- Persistent non-filing can eventually lead to registration cancellation.
The practical fix
Almost every late filing we see traces back to the same root cause: nobody was tracking the calendar centrally. Whether you handle GST yourself or work with us, the fix is the same — put every due date somewhere you'll actually see it before it passes, not after.
If you'd rather not track it yourself, our Resources page has a live compliance calendar, or you can just get in touch and we'll take it off your plate entirely.