GST late fee & interest calculator
Work out exactly what a late GSTR-1, GSTR-3B or GSTR-9 will cost you — with the correct turnover-slab cap applied, and 18% interest computed on net cash liability under Rule 88B rather than on gross tax. Most free calculators get both of those wrong.
Your return
Interest inputs
How the GST late fee actually works
Section 47 of the CGST Act sets a statutory late fee of ₹100 per day under each of the CGST and SGST Acts — ₹200 a day in total. That headline figure is almost never what you pay. Notifications 4/2018 and 76/2018 reduced it, and notifications 19/2021 and 20/2021 capped it by turnover. The reduced rates are what the portal charges, and they are what this calculator applies.
Per-day rate — GSTR-1 and GSTR-3B
| Return | CGST/day | SGST/day | Total per day |
|---|---|---|---|
| Non-nil | ₹25 | ₹25 | ₹50 |
| Nil | ₹10 | ₹10 | ₹20 |
Maximum late fee by turnover
| Category | Aggregate turnover (previous FY) | Cap per return |
|---|---|---|
| Nil return | Any | ₹500 |
| Non-nil | Up to ₹1.5 crore | ₹2,000 |
| Non-nil | ₹1.5 crore – ₹5 crore | ₹5,000 |
| Non-nil | Above ₹5 crore | ₹10,000 |
Annual return — GSTR-9 and GSTR-9C
| Aggregate turnover | Late fee per day | Cap |
|---|---|---|
| Up to ₹2 crore | Exempt from filing GSTR-9 entirely — a permanent exemption since Notification 15/2025-CT | |
| ₹2 crore – ₹5 crore | ₹50 | 0.04% of turnover in the State/UT |
| ₹5 crore – ₹20 crore | ₹100 | 0.04% of turnover in the State/UT |
| Above ₹20 crore | ₹200 | 0.50% of turnover in the State/UT |
Two points worth knowing. The above-₹20-crore slab was never reduced — that is still the full statutory rate. And GSTR-9C is not treated as a separate return: under Circular 246/03/2025-GST the section 47(2) late fee keeps running until both GSTR-9 and GSTR-9C are on file.
Interest — and why the number is usually smaller than you fear
Interest is 18% per annum under section 50(1). The proviso to that section, read with Rule 88B(1), restricts it: where a return is filed late and no section 73 or 74 proceedings are running, interest applies only to the tax discharged by debiting the Electronic Cash Ledger. Liability settled from input tax credit carries no interest. And following the 53rd GST Council amendment, any balance already sitting in the cash ledger on the due date is deducted before interest is computed.
The practical effect for a business with healthy input credit is that a large-looking liability can carry almost no interest, because most of it was never paid in cash. A business paying mostly in cash sees the opposite. This is why a flat "18% on the tax amount" calculator is misleading in both directions.
Two changes that have caught a lot of businesses out
The three-year bar. Sections 37(5), 39(11), 44(2) and 52(15) prevent you filing any GST return more than three years after its original due date. Portal enforcement started with the November 2025 tax period. Once a return crosses that line it cannot be filed at all, and the input tax credit attached to it is gone permanently. If you are carrying returns from 2022-23 or earlier, that window is closing month by month.
GSTR-3B is now hard-locked. From the July 2025 tax period, Table 3 auto-populated liability cannot be edited — corrections must go through GSTR-1A before 3B is filed. From January 2026 the credit side is locked too, and filing is blocked where the ITC claimed does not reconcile with GSTR-2B. Reconciliation is no longer optional housekeeping; it is a precondition to filing.
Due dates for FY 2026-27
| Return | Who | Due |
|---|---|---|
| GSTR-1 monthly | Turnover above ₹5 crore, or not in QRMP | 11th of the following month |
| GSTR-1 quarterly | QRMP | 13th of the month after quarter end |
| GSTR-3B monthly | Turnover above ₹5 crore | 20th of the following month |
| GSTR-3B quarterly — Group X | Maharashtra, Gujarat, Karnataka, TN and the south/west | 22nd of the month after quarter end |
| GSTR-3B quarterly — Group Y | Rajasthan, Delhi, UP, Punjab and the north/east | 24th of the month after quarter end |
| PMT-06 | QRMP, first two months of the quarter | 25th of the following month |
| CMP-08 | Composition dealers | 18th of the month after quarter end |
| GSTR-9 / 9C | Annual | 31 December following the financial year |
Common questions
How much is the late fee for GSTR-3B?
For a non-nil GSTR-3B the reduced late fee is ₹50 per day (₹25 CGST + ₹25 SGST). For a nil return it is ₹20 per day (₹10 + ₹10). The total is then capped by your previous financial year's aggregate annual turnover: ₹500 for a nil return, ₹2,000 up to ₹1.5 crore, ₹5,000 between ₹1.5 crore and ₹5 crore, and ₹10,000 above ₹5 crore.
Is the late fee for GSTR-1 the same as GSTR-3B?
The rates and caps are identical, but the 'nil' test is different and this is where most calculators go wrong. GSTR-1 is nil when there are no outward supplies. GSTR-3B is nil when there is no tax payable. A return can be nil for one and not the other, so the two must be computed separately.
How is GST interest calculated on a late return?
Interest runs at 18% per annum under section 50(1) read with Rule 88B. Where the return is filed late and no proceedings under section 73 or 74 are on foot, interest applies only to the tax actually discharged from the Electronic Cash Ledger — and any balance already lying in that ledger on the due date is deducted first. Interest is charged for the actual number of days of delay, not per month.
When does 24% interest apply instead of 18%?
Only where input tax credit has been both wrongly availed AND utilised. The test under Rule 88B(3) is conjunctive. If credit was wrongly availed but never utilised — the credit ledger balance never fell below the wrongly-availed amount — you simply reverse it and no interest arises at all. Ordinary late filing is always 18%.
Is there a late fee on CMP-08?
No. CMP-08 is a statement, not a return, so section 47 does not apply to it. Only 18% interest on the tax paid late is chargeable. Several competitor calculators wrongly charge a per-day fee here.
Can I still file a return that is more than three years old?
No. Sections 37(5), 39(11), 44(2) and 52(15) bar filing any GST return after three years from its original due date. Portal enforcement began with the November 2025 tax period. The bar is permanent and the related input tax credit is lost for good.
What is the maximum GST late fee I can be charged?
For GSTR-1 and GSTR-3B the hard ceiling is ₹10,000 per return per period, and that only applies above ₹5 crore turnover. For most MSMEs the real ceiling is ₹2,000 per return. The interest, which is uncapped, is usually the larger number once a delay runs past a few months.
Have a professional check this
Send us what the tool showed you. We will tell you what the position actually is, and what it would cost to deal with, before you commit to anything.
Behind on more than one return?
Late fees compound quietly. A business three months behind on GSTR-1 and GSTR-3B is usually paying more each month in fees and interest than a full compliance retainer costs.
| Solo Lite — one GSTIN, monthly filings | ₹2,999/mo |
| Foundation Shield — books + filings | ₹4,999/mo |
| Compliance Control — multi-GSTIN + MIS | ₹9,999/mo |
Plus 18% GST. No lock-in — 15 days' notice.
See all plans