GST Late Fee & Interest Calculator
Missing a GST return deadline triggers two separate costs: a late fee under Section 47 for the delay in filing, and interest under Section 50 on any tax that was paid late. This calculator computes both for GSTR-3B, GSTR-1, GSTR-4, GSTR-9 and GSTR-7, applying the per-day rates, the nil-return concession and the turnover-based caps that are easy to forget.
Late fee per day (CGST + SGST combined)
- GSTR-3B / GSTR-1: ₹50 per day (₹25 + ₹25); nil return ₹20 per day (₹10 + ₹10)
- Maximum: ₹500 for nil returns; ₹2,000 if preceding-year turnover ≤ ₹1.5 crore; ₹5,000 for ₹1.5–5 crore; ₹10,000 above ₹5 crore
- GSTR-4 (annual, composition): ₹50 per day, capped at ₹2,000 (₹500 for nil)
- GSTR-9 (annual): ₹50 per day up to ₹5 crore turnover, ₹100 per day for ₹5–20 crore, ₹200 per day above; capped at 0.04% of turnover (0.5% above ₹20 crore)
Interest
Interest runs at 18% per annum on the net cash liability — the tax paid through the electronic cash ledger after setting off ITC — from the day after the due date until the date of payment. Formula: Interest = Tax × 18% × Days ÷ 365. Wrongly availed and utilised ITC attracts 24%. GSTR-1 and GSTR-9 carry late fee only because no tax is paid with them.
Worked example
GSTR-3B for August 2026 was due on 20 September 2026 and filed on 16 October 2026 — 26 days late — by a taxpayer with ₹1.2 crore turnover and ₹45,000 net cash tax. Late fee = 26 × ₹50 = ₹1,300 (below the ₹2,000 cap), split ₹650 CGST + ₹650 SGST. Interest = 45,000 × 18% × 26 ÷ 365 = ₹577. Total cost of the delay: ₹1,877. Had the return been nil, the fee would be 26 × ₹20 = ₹520, capped at ₹500.
Points to remember
Late fee is auto-populated in the next return and must be paid in cash before filing. The portal does not compute interest automatically in every case, so self-assess and pay it to avoid notices under DRC-01. Periodic amnesty schemes reduce or waive fees for old periods — check current notifications before paying large sums for returns older than a year.
For QRMP taxpayers the late fee applies to the quarterly GSTR-3B, while the monthly PMT-06 payments carry only interest if short-paid. Composition dealers face late fee on the annual GSTR-4 but not on the quarterly CMP-08 statement, although interest still applies to late CMP-08 payments.
Frequently Asked Questions
Is late fee charged on GSTR-1 as well as GSTR-3B?
Yes, both carry late fee independently. Interest, however, is charged only with GSTR-3B because that is where tax is paid.
Is interest calculated on gross tax or net cash tax?
On net cash tax after ITC set-off, as clarified by the proviso to Section 50(1) effective retrospectively from 1 July 2017.
What is a nil return for late-fee purposes?
A return with no outward supplies, no inward supplies attracting reverse charge and no tax liability for the period.
Can late fee exceed the tax due?
Yes. Late fee is independent of tax and is limited only by the turnover-based caps.
Disclaimer: This tool is for general information and estimation only. Tax rates and rules change — verify with official sources or a professional before acting. Read full disclaimer.