GST Late Fee and Interest for Late Filing (2026 Guide)

Missed a GST return deadline? You're not alone — and the cost is usually smaller than people fear, but it adds up daily until you file. Here's exactly how the GST late fee and interest are calculated, so you know what you owe before you log in to pay.

Work it out instantly with the free GST Late Fee Calculator → — no sign-up needed.

The two charges: late fee + interest

When you file a GST return after the due date, there are two separate charges:

1. Late fee — a fixed per-day penalty for filing late, regardless of whether you owe tax.
2. Interest — 18% per annum on any tax you pay late.

They're calculated differently, so let's take them one at a time.

Late fee: ₹50 (or ₹20) per day

The late fee for GSTR-3B and GSTR-1 is:

• ₹50 per day for a normal return — split as ₹25 CGST + ₹25 SGST.
• ₹20 per day for a nil return (no sales/tax that period) — ₹10 CGST + ₹10 SGST.

It's counted from the day after the due date up to the actual date of filing.

The cap (this is important)

The late fee is capped per return, based on your annual turnover, under the rationalised structure:

Return type / turnover	Maximum late fee
Nil return	₹500
Turnover up to ₹1.5 crore	₹2,000
Turnover ₹1.5–5 crore	₹5,000
Turnover above ₹5 crore	₹10,000

So even if you're months late on a nil return, the late fee won't exceed ₹500.

Interest: 18% per annum on tax paid late

If you had a tax liability and paid it late, interest at 18% per annum applies on the net tax paid in cash, for the number of days delayed:

Interest = Tax × 18% × (days late ÷ 365)

For example, ₹50,000 of tax paid 30 days late: ₹50,000 × 18% × 30/365 ≈ ₹740.

Nil returns have no tax liability, so there's no interest — only the late fee.

A quick example

You file GSTR-3B 20 days late, with ₹50,000 of tax due, turnover under ₹1.5 crore:

• Late fee: 20 days × ₹50 = ₹1,000 (under the ₹2,000 cap) → ₹500 CGST + ₹500 SGST
• Interest: ₹50,000 × 18% × 20/365 ≈ ₹493
• Total ≈ ₹1,493

Try it with your own dates and amount →

How to avoid late fees for good

Late fees are almost always a symptom of one thing: scrambling to pull numbers together at deadline. The fix is keeping your invoices and payments organised through the month, so filing is a five-minute export, not a week of spreadsheet archaeology.

That's exactly what Simple Billing does — every invoice is GST-formatted with the right CGST/SGST/IGST split, and your tax summary is ready when you need it. Start free — no credit card.

This guide is an estimate to help you plan. GST rules and caps change and can vary by return; always confirm the exact figure on the official GST portal or with your accountant.