GST Interest & Late Fee Calculator
Missed a GSTR-3B due date? Estimate the Section 50 interest on your net tax liability plus the Section 47 late filing fee, so you know the total payable before you file.
Reviewed by the CalcCafe editorial team · Last updated 18 July 2026 · How we test our tools
Example
Suppose your net tax liability (after using input tax credit) is ₹1,00,000 and you file GSTR-3B 30 days after the due date. Interest under Section 50 is 1,00,000 × 18% × 30⁄365 ≈ ₹1,479. The late fee runs at ₹50 per day (₹25 CGST + ₹25 SGST), so 30 days adds ₹1,500 before the turnover-based cap. Total payable ≈ ₹1,02,979 — the ₹1,00,000 tax plus about ₹2,979 in interest and fees.
How it works
Interest = net tax liability × 18% × days delayed ⁄ 365, per Section 50(1) of the CGST Act read with Rule 88B — simple (not compound) interest charged on the portion of tax paid through the electronic cash ledger, counted from the day after the due date to the date of payment. The late fee under Section 47 accrues per day of delay: ₹50/day for a normal GSTR-3B (₹25 CGST + ₹25 SGST) or ₹20/day for a nil return (₹10 + ₹10), subject to the statutory caps described below. Total payable = tax + interest + late fee.
Good to know
Section 50(1) of the CGST Act charges interest at 18% per annum on delayed payment of GST. Since the retrospective amendment effective 1 July 2017 (implemented through Rule 88B in July 2022), interest for a late-filed GSTR-3B applies only to the net cash liability — the part of the tax you debit from the electronic cash ledger — not to the portion settled from your input tax credit balance. If your ITC fully covers the liability, a late return generally attracts only the late fee, not interest. Interest is computed day-wise from the day after the due date until the date the tax is actually paid.
GSTR-3B is normally due on the 20th of the following month for monthly filers. Taxpayers under the QRMP (quarterly return, monthly payment) scheme file quarterly, with due dates of the 22nd or 24th of the month after the quarter depending on their state, and pay tax monthly through PMT-06. The clock for both interest and late fee starts from your applicable due date, so check which cycle you are on before entering the days delayed.
The Section 47 late fee is capped based on your aggregate turnover in the previous financial year. For GSTR-3B, the combined CGST+SGST cap is ₹2,000 for turnover up to ₹1.5 crore, ₹5,000 for turnover between ₹1.5 crore and ₹5 crore, and ₹10,000 above ₹5 crore. A nil return is capped at ₹500 in total regardless of turnover. This calculator deliberately shows the uncapped per-day figure so you can see how quickly it accrues; the GST portal applies the cap automatically when you file.
In practice the GST portal auto-populates the late fee in the next period's GSTR-3B and expects you to declare interest in Table 5.1, with the system now suggesting a computed figure as well. Both must be paid in cash — late fee and interest cannot be set off against input tax credit. If you have received a notice, interest can also be paid through Form DRC-03. Keep in mind that continued non-filing can lead to best-judgment assessment under Section 62 and eventually suspension of your GSTIN, so the sums here are the cheap end of non-compliance.
Frequently asked questions
Is GST interest charged on the gross tax or only the cash portion?
For a late-filed GSTR-3B, interest under Section 50 applies only to the net cash liability, the amount you pay through the electronic cash ledger after using input tax credit. If ITC covers the whole liability, a late return normally attracts only the late fee. Interest on wrongly availed and utilised ITC is a separate matter, also charged at 18% under Rule 88B.
How much is the GSTR-3B late fee and what are the caps?
It accrues at 50 rupees per day (25 CGST plus 25 SGST) or 20 rupees per day for a nil return. The total is capped at 500 rupees for nil returns, and at 2,000, 5,000 or 10,000 rupees for other returns depending on whether your previous-year turnover is up to 1.5 crore, up to 5 crore, or above 5 crore.
Is my tax data uploaded anywhere?
No, this calculator runs entirely in your browser. Your liability figures never leave your device, and the page works offline once loaded.
Is this GST interest calculator free?
Yes, completely free with no sign-up and no limits. It gives an educational estimate; the GST portal computes the legally binding figure when you file.
People also ask
What is the interest rate for late payment of GST?
18% per annum, simple interest, under Section 50(1) of the CGST Act, counted from the day after the due date to the date of payment. A higher 24% rate historically applied to certain wrongly availed ITC situations, but since the 2022 amendment wrongly availed and utilised ITC is also charged at 18%.
Is interest payable if I file GSTR-3B late but have enough ITC?
Generally no. Rule 88B computes interest on the portion of tax debited from the electronic cash ledger. If input tax credit covers the entire liability, the cash component is zero and only the late fee applies. This relief covers returns filed late, not tax short-paid outside the return.
Can the GST late fee be waived?
Only by government notification. The GST Council has periodically announced amnesty schemes that waived or reduced late fees for specified past periods, and the current turnover-based caps came from such notifications. There is no route to request an individual waiver on the portal.
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Sources & references
These tools follow our methodology and provide educational estimates only — verify important figures with a qualified professional.