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GST & Tax

GST Late Fee & Interest Calculator

Filed GSTR-3B late? Calculate the exact late fee (₹50/day, ₹20 for nil returns) plus 18% annual interest on your outstanding tax, so there are no surprises on the portal.

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About the GST Late Fee & Interest Calculator

Content reviewed 6 August 2026

Miss a GSTR-3B or GSTR-1 deadline and two charges stack up: a per-day late fee, and 18% annual interest on any tax you owe. The late fee is ₹50 a day (₹25 CGST + ₹25 SGST) for a return with tax, ₹20 a day for a nil return, subject to a cap.

The interest is the part people underestimate — it runs at 18% p.a. on the net tax paid in cash, from the due date until you actually file, and the portal computes it automatically. This tool gives you the number before you log in.

Worked example

File 15 days late with ₹40,000 of tax due: late fee ₹750 (15 × ₹50), interest ₹40,000 × 18% × 15/365 ≈ ₹296. Total extra ≈ ₹1,046 on top of the tax itself.

Frequently asked questions

Is the late fee charged even on a nil return?+

Yes — a nil GSTR-3B or GSTR-1 filed late attracts ₹20 per day (₹10 CGST + ₹10 SGST), capped at ₹500 per return. Filing on time, even with nothing to report, avoids it.

Can the interest be waived?+

Interest at 18% on delayed tax is statutory and generally not waived. Late-fee amnesty schemes appear occasionally, but never rely on one — file first, dispute later if a waiver is announced.

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