How it works
Late fee. The CGST Act allows ₹100 a day up to ₹5,000 (s.47(1)), and the same under the state Act. Notifications waive the part above:
| Item | Per day (CGST + SGST) | Cap (CGST + SGST) |
|---|---|---|
| Nil return | ₹10 + ₹10 | ₹250 + ₹250 |
| Turnover up to ₹1.5 crore | ₹25 + ₹25 | ₹1,000 + ₹1,000 |
| ₹1.5 crore to ₹5 crore | ₹25 + ₹25 | ₹2,500 + ₹2,500 |
| Above ₹5 crore | ₹25 + ₹25 | ₹5,000 + ₹5,000 |
Turnover is aggregate turnover in the preceding financial year. The caps apply to tax periods from June 2021.
Interest. Interest = tax paid in cash × 18% × days late ÷ 365 (s.50(1); rate fixed by Notification 13/2017-Central Tax).
Worked example
Kaveri Agencies (turnover ₹1.2 crore last year) files its GSTR-3B for September 2026, due on 20 Oct 2026, on 30 Oct 2026. It pays ₹40,000 of tax in cash with the return.
- Days late: 10.
- Late fee: ₹25 × 10 = ₹250 CGST and ₹250 SGST = ₹500 (well under the ₹2,000 cap).
- Interest: ₹40,000 × 18% × 10 ÷ 365 = ₹197.26, about ₹197.
Total to pay: ₹697.
Notes and edge cases
- Extended due dates: if the government extended the due date for that month, use the extended date.
- Proposed waiver for small taxpayers: the 57th GST Council (8 Oct 2026) recommended no late fee on GSTR-3B for turnover up to ₹5 crore when the return is filed by the end of the month in which it was due. We found no notification giving effect to it by 1 Nov 2026, so the tool does not apply it. Check the current notification before you pay.
- Late GSTR-1 has a fee but no interest of its own; interest follows the tax, which is paid with GSTR-3B.
- Paid by credit: tax set off against input tax credit at the time of filing does not attract interest under the proviso; ask your CA about credit wrongly taken or used, which follows s.50(3).
- Amnesty schemes sometimes waive fees for old periods; check the latest notifications before paying a large fee.