GST Late Fee & Interest Calculator

How the GST late fee works

If a return is filed after its due date, a fixed daily late fee is charged under Section 47 of the CGST Act. It depends only on the number of days of delay, not on the tax amount, and is levied separately and equally under CGST and SGST.

• Regular return (with tax liability): ₹50 per day — ₹25 CGST + ₹25 SGST.
• Nil return (no tax liability): ₹20 per day — ₹10 CGST + ₹10 SGST.

Maximum late fee (caps)

No matter how long the delay, the late fee cannot exceed a statutory cap. For nil returns the cap is ₹500 (₹250 + ₹250). For returns with tax liability, the cap is linked to annual aggregate turnover:

• Turnover up to ₹1.5 crore: up to ₹2,000 (₹1,000 + ₹1,000).
• Turnover ₹1.5 – 5 crore: up to ₹5,000 (₹2,500 + ₹2,500).
• Turnover above ₹5 crore: up to ₹10,000 (₹5,000 + ₹5,000).

Interest on late payment

Interest is separate from the late fee. Under Section 50, if you pay your tax after the due date, interest of 18% per annum applies on the net tax paid late, using the formula Tax × 18% × days ÷ 365. If input tax credit was wrongly availed and utilised, the rate is 24% per annum. A nil return has no tax, so it carries no interest.

Worked example: 45 days late on GSTR-3B

Suppose your GSTR-3B due on the 20th is filed 45 days late, your annual turnover is ₹80 lakh, and ₹40,000 of tax was paid late in cash. Late fee: ₹50 × 45 = ₹2,250, but the cap for turnover up to ₹1.5 crore is ₹2,000 — so you pay ₹2,000 (₹1,000 CGST + ₹1,000 SGST). Interest: 40,000 × 18% × 45 ÷ 365 = ₹887 (approx.), payable in cash. Total cost of the delay: about ₹2,887 — and the return cannot be filed until both are paid.

Late fee vs interest — two separate charges

People often mix these up. The late fee (Section 47) punishes late filing — it runs per day whether or not any tax was due, which is why even nil returns attract ₹20/day. Interest (Section 50) compensates for late payment of tax — it applies only to the tax paid late in cash, at 18% per annum. A nil return filed late owes a late fee but no interest; a return filed on time with tax short-paid owes interest but no late fee. This calculator computes both, side by side.

Why filing even one day late is expensive

The fee is per day, not per month, and both CGST and SGST halves accrue from day one. A quarterly filer who forgets a nil GSTR-3B for a month owes ₹600+ before noticing; a regular filer with liability racks up ₹50/day until the cash and the return go in. Two habits fix this: put the due dates (11th for monthly GSTR-1, 20th for monthly GSTR-3B — dates differ under QRMP) in your phone calendar with a 3-day-early alarm, and file nil returns immediately since they take two minutes.

GST late payment interest calculator: how the interest is worked out

Interest under Section 50 runs on the net tax paid late in cash, for each day from the day after the due date until the day the tax is actually paid. The formula used by the calculator is:

Interest = Tax paid late × 18% × days of delay ÷ 365

Interest applies only to the part of the tax that was not already in your electronic cash ledger by the due date. Tax settled from input tax credit that was available on time does not attract interest, which is why the calculator asks for the net tax paid late rather than your total liability.

GST penalty, late fee and interest: what each one means

People searching for a “GST penalty calculator” usually mean the late fee, but the law uses three separate terms:

• Late fee (Section 47): a fixed amount per day for filing a return late, with the caps shown above. This is what most small businesses pay.
• Interest (Section 50): compensation for paying tax late, calculated on the tax amount and number of days.
• Penalty (Sections 122 to 125): imposed by an officer for specific offences, such as issuing an invoice without supplying goods. A general penalty of up to ₹25,000 can apply under Section 125 where no specific penalty is set out. Penalties are not automatic and cannot be worked out by a calculator.