GSTCalculator
GST Late Fee and Interest Calculator
Work out the late fee and interest for a GSTR-1 or GSTR-3B filed after its due date, with the CGST and SGST shares and the cap for your turnover.
For the interest. Leave it empty to work out the late fee only.
Enter the due date and the date you filed to see the late fee.
How it is calculated
- Days late = the date you filed (and paid) minus the due date. A return filed on or before the due date has no late fee.
- Late fee = days late × the daily fee, but never more than the cap. The daily fee is ₹50 for a return with tax to pay (₹25 CGST plus ₹25 SGST) and ₹20 for a nil return (₹10 plus ₹10).
- The cap for a nil return is ₹500. For other returns it depends on the turnover of the previous financial year: ₹2,000 up to ₹1.5 crore, ₹5,000 up to ₹5 crore, ₹10,000 above.
- Interest = tax paid late × 18% × days late ÷ 365, from the day after the due date to the day the tax is paid.
Example. A GSTR-3B with ₹1,00,000 of tax, due on 20 September and filed and paid on 20 October (30 days late), for a business under ₹1.5 crore: late fee 30 × ₹50 = ₹1,500 (₹750 CGST and ₹750 SGST), interest ₹1,00,000 × 18% × 30 ÷ 365 = ₹1,479.45, so ₹2,979.45 in all.
Rules and sources
Rules last checked on October 19, 2026
This is an illustrative calculation for general guidance, not professional advice. Rates and limits change by notification, so confirm the applicable law before you rely on a figure.
Frequently asked questions
What is the late fee for filing GSTR-3B or GSTR-1 late?
The late fee is ₹50 a day (₹25 CGST and ₹25 SGST) for a return with tax to pay, and ₹20 a day (₹10 and ₹10) for a nil return, from the day after the due date, up to a cap. The cap is ₹500 for a nil return, and ₹2,000, ₹5,000 or ₹10,000 by turnover for other returns.
Is interest charged on top of the late fee?
Yes. Interest is charged separately at 18% a year on the tax that was paid late, from the day after the due date until it is paid. The late fee is charged on the return, whether or not there is tax to pay.
Which due date do I enter?
The one that applied to your return. Due dates differ by return and by monthly or quarterly filing, and they are sometimes extended by notification, so this calculator asks for the date instead of guessing it.
What does this calculator leave out?
Relief or waiver notifications for particular periods, the annual return GSTR-9, interest on input tax credit that was wrongly claimed, and any penalty. Use it as an estimate and confirm the position before paying.