GST Late Fee and Interest Calculator
Enter the due date, the filing date, last year's turnover and the tax paid in cash. Get the late fee split into CGST and SGST, whether the cap applied, and the interest.
GSTR-3B: 20th of next month (monthly). GSTR-1: 11th.
Decides the cap: up to ₹1.5 crore, ₹5 crore, or above.
Net tax paid through the cash ledger — the base for interest.
Result
- Days late
- 26
- CGST late fee
- ₹650.00
- SGST late fee
- ₹650.00
- Late fee
- ₹1,300.00
- Interest @ 18% a year
- ₹1,025.75
- Late fee + interest
- ₹2,325.75
Cap for this return: ₹5,000.00.
Quick answer
GST late fee for GSTR-3B and GSTR-1 is ₹50 a day (₹25 CGST + ₹25 SGST), or ₹20 a day for a nil return, capped at ₹500 for nil returns and ₹2,000, ₹5,000 or ₹10,000 per return for turnover up to ₹1.5 crore, up to ₹5 crore and above ₹5 crore. Interest is 18% a year on the tax paid late in cash, for each day of delay.
| Late fee per day | ₹50 (₹20 for nil returns) |
|---|---|
| Cap — nil return | ₹500 |
| Cap — turnover up to ₹1.5 crore | ₹2,000 |
| Cap — ₹1.5 crore to ₹5 crore | ₹5,000 |
| Cap — above ₹5 crore | ₹10,000 |
| Interest | 18% a year on net tax paid in cash |
A GST return filed after its due date costs two things. The late fee is a fixed amount per day of delay, charged even when no tax is due, and it is capped per return according to the previous year's turnover. Interest is separate: it runs on the tax itself, from the day after the due date to the day the tax is paid.
Late fee is paid in cash through the electronic cash ledger; input tax credit cannot be used for it. This calculator applies the caps that have applied to GSTR-3B and GSTR-1 since June 2021. Rates and limits as of 13 October 2026.
The formula
- Late fee
Days late × ₹50 (₹20 for nil), up to the cap- Split
Half CGST, half SGST- Interest
Tax paid in cash × 18% × Days late ÷ 365
A worked GST late fee example
GSTR-3B for September is due on 20 October. A business with ₹3 crore turnover last year files on 15 November — 26 days late — with ₹80,000 of tax paid in cash. Late fee = 26 × ₹50 = ₹1,300 (₹650 CGST + ₹650 SGST), under the ₹5,000 cap. Interest = 80,000 × 18% × 26 ÷ 365 = ₹1,025.75.
Had the same return been 120 days late, the fee would have been 120 × 50 = ₹6,000, capped at ₹5,000. Interest has no cap: it keeps running until the tax is paid.
Interest is only on the tax paid in cash
Since the law was amended, interest on a late GSTR-3B is charged on the net tax liability paid through the cash ledger — the part not set off against input tax credit. If ₹2,00,000 of output tax was settled with ₹1,20,000 of credit and ₹80,000 of cash, interest runs on ₹80,000 only.
Input tax credit claimed wrongly and used is a different matter, with its own interest and notices — this calculator covers a return that is simply filed late.
Avoiding late fees
Most late fees come from waiting on data: sales not yet invoiced in the system, purchase bills not entered, GSTR-2B not matched. A system where invoices are raised from dispatch and purchase bills are entered at the GRN makes the return a summary of work already done rather than a month-end scramble.
Keep a calendar of due dates — GSTR-1 on the 11th, GSTR-3B on the 20th for monthly filers — and remember that returns can no longer be filed once three years have passed since their due date.
Questions people ask.
What is the late fee for GSTR-3B?
₹50 a day (₹25 CGST + ₹25 SGST), or ₹20 a day for a nil return, capped at ₹500 for nil returns and ₹2,000 / ₹5,000 / ₹10,000 by turnover.
Is the GSTR-1 late fee the same as GSTR-3B?
Yes — the same per-day amounts and the same turnover-based caps apply to GSTR-1.
How is interest on late GST payment calculated?
18% a year on the tax paid late in cash, for each day from the day after the due date to the date of payment: Tax × 18% × days ÷ 365.
Can late fee be paid from input tax credit?
No. The late fee must be paid in cash through the electronic cash ledger.
Is there a late fee if there is no tax to pay?
Yes. A nil return filed late attracts ₹20 a day, up to ₹500.
Which turnover decides the late fee cap?
The aggregate turnover of the previous financial year.
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