GST Interest & Late Fee Calculator

How the GST late fee works

If you file a return after its due date, Section 47 of the CGST Act charges a late fee for every day of delay. The same amount is charged under the state GST Act, so the total you pay is double the CGST figure. Since 2021 the government has capped the fee based on your aggregate annual turnover (AATO) in the previous financial year.

Worked example

A business with ₹1 crore turnover files its GSTR-3B 30 days late with ₹1,00,000 of tax payable in cash. Late fee: 30 × ₹50 = ₹1,500 (under the ₹2,000 cap), split ₹750 CGST and ₹750 SGST. Interest: ₹1,00,000 × 18% × 30 ÷ 365 = ₹1,479.45. Total: ₹2,979.45.

GSTR-1 must be filed before GSTR-3B for the same period, and the portal will not let you file GSTR-3B until the late fee is paid.

A longer delay shows how the cap works. The same ₹1 crore business files 75 days late with ₹50,000 of cash tax. The fee would be 75 × ₹50 = ₹3,750, but the cap stops it at ₹2,000. Interest is ₹50,000 × 18% × 75 ÷ 365 = ₹1,849.32, and interest has no cap. After the fee reaches its ceiling, every extra day costs only interest.

Nil returns cap out quickly. A nil GSTR-3B filed 45 days late would attract 45 × ₹20 = ₹900, which the cap reduces to ₹500 (₹250 CGST and ₹250 SGST).

Due dates the calculator counts from

When the government extends a due date by notification, the late fee and interest run from the extended date. Check the compliance calendar for extensions in force.

How interest is worked out

Section 50(1) charges 18% a year on tax paid late, counted in days. Since the proviso to Section 50(1) took effect, interest on a late return is charged only on the part of the tax paid in cash, so tax set off against ITC already in your ledger carries no interest.

Section 50(3) is separate. It charges 18% on input tax credit that was wrongly availed and used to pay tax, from the date of use. Credit that sat unused in the ledger attracts no interest, even if it has to be reversed.

Costs bigger than the late fee

• Lost ITC. Section 16(4) lets you claim credit for a financial year only up to 30 November of the next year, or until you file the annual return if that is earlier. A GSTR-3B filed after that date cannot carry ITC for invoices of the old year. For most businesses this costs far more than the late fee.
• The 3-year bar. The Finance Act, 2023 stops GSTR-1, GSTR-3B and GSTR-9 from being filed more than three years after their due date, and the portal now enforces it. A return past that point cannot be filed at all.
• Blocked e-way bills. A taxpayer who misses two consecutive GSTR-3B returns (two quarters on QRMP) cannot generate e-way bills until the returns are filed.
• Suspension or cancellation. Not filing returns for six months in a row is a ground for the officer to cancel registration under Section 29.

GSTR-9 late fee example

A business with ₹3 crore turnover files GSTR-9 60 days late. The fee is 60 × ₹50 = ₹3,000. The cap for this band is 0.04% of turnover in the state, which is ₹12,000, so the full ₹3,000 applies, split ₹1,500 CGST and ₹1,500 SGST.

Late because GSTR-2B reconciliation is still open? The GSTR-2B reconciliation tool matches a purchase register in the browser, and the liability calculator gives the cash figure that interest is charged on.