GST Late Fee & Interest Calculator
Work out the late fee and 18% interest on a delayed GSTR-3B or GSTR-1 return. Enter your due date, filing date and tax payable.
How is GST late fee calculated?
Late fee for filing GSTR-3B or GSTR-1 after the due date is ₹50 per day (₹25 CGST + ₹25 SGST) for a return with tax, and ₹20 per day (₹10 + ₹10) for a nil return. It is charged for every day of delay until the return is filed.
The total late fee is capped based on turnover under the rationalised structure introduced by CGST notifications 19/2021 and 20/2021: ₹500 for nil returns, ₹2,000 where annual turnover is up to ₹1.5 crore, ₹5,000 between ₹1.5 crore and ₹5 crore, and ₹10,000 above ₹5 crore. These figures follow the rules published on the official GST portal.
Separately, interest at 18% per annum is charged under Section 50 of the CGST Act on the net tax paid in cash after the due date, calculated for the actual number of days of delay.
How is GST interest calculated?
Late fee and interest are two separate charges and they are worked out differently. The late fee is a fixed amount per day of delay in filing. Interest is a percentage of the tax you paid late, and it is charged under Section 50 of the CGST Act at 18% per annum.
Interest = Tax paid in cash × 18% × Days delayed / 365
Three details decide the figure. Interest runs on the tax actually discharged in cash, not on the gross liability, so the portion settled from your input tax credit balance does not attract it. The count is in actual days — from the day after the due date to the day the payment is made — not in whole months. And interest itself must always be paid in cash: credit in the electronic credit ledger cannot be used against it.
Worked example: ₹1,00,000 of tax settled in cash, paid 40 days after the due date, gives 1,00,000 × 18% × 40 ÷ 365 = ₹1,973. The late fee for those days is added on top of that.
Enter your figures above and the calculator returns both numbers — late fee and interest — for the period you select.
Frequently asked questions
How do I calculate interest on late GST payment?
Multiply the tax you settled in cash by 18%, then by the number of days of delay divided by 365. The delay is counted in actual days from the day after the due date to the date of payment, and only the cash portion of the liability counts — tax settled from your input tax credit balance does not attract interest. On ₹1,00,000 paid 40 days late, the interest is ₹1,973.
What is the late fee per day for GST returns?
₹50 per day for a normal return (₹25 CGST + ₹25 SGST) and ₹20 per day for a nil return (₹10 + ₹10), subject to the turnover-based maximum cap.
What is the interest rate on late GST payment?
Interest is 18% per annum under Section 50 of the CGST Act, charged on the net tax liability discharged in cash for the number of days the payment is delayed.
Is there a maximum GST late fee?
Yes. The late fee is capped at ₹500 for nil returns, ₹2,000 up to ₹1.5 crore turnover, ₹5,000 up to ₹5 crore, and ₹10,000 above ₹5 crore per return.
Does interest apply to a nil GST return?
No. A nil return has no tax liability, so only the late fee applies and no interest is charged.
How is the 18% GST interest calculated?
Interest is worked out as net tax × 18% × number of days of delay ÷ 365. For example, ₹50,000 paid 30 days late attracts about ₹739 of interest.
Is interest charged on the full tax or only the cash portion?
Interest is charged only on the net tax paid in cash after adjusting input tax credit, not on the gross liability — the portion settled through ITC is not subject to interest.
Is there a late fee for filing GSTR-1 late?
Yes. GSTR-1 carries the same ₹50 per day (₹20 for a nil return) late fee with the same turnover-based caps, but it attracts no interest because no tax is paid through GSTR-1.
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