GST Late Fee & Interest Calculator

Last updated: Jul 22, 2026 | Reviewed by Calkulator Team | 2 min read

Tax

Check late filing penalties before they pile up

Filing GSTR-3B or GSTR-1 after the due date attracts ₹50/day late fee (₹20/day for nil returns) plus 18% annual interest on the tax amount. A one-month delay on ₹2 lakh tax liability adds ₹4,500 in penalties.

File nil returns on time even if there are no transactions — late fee applies regardless of tax amount.

Filing Details

GSTR Type

Tax Amount (₹)

₹

Unpaid / delayed tax liability (0 for nil return)

Annual Turnover (₹)

₹

Required for GSTR-9 max late fee cap

Due Date

Last date to file without penalty

Actual Filing Date

NIL Return (no tax, no transactions)

Late Fee Rules

GSTR-3B: ₹50/day (₹20/day NIL), capped ₹10,000

GSTR-1: ₹50/day (₹20/day NIL), capped ₹10,000

GSTR-9: ₹200/day, capped 0.25% of turnover

Interest on unpaid tax: 18% p.a. (GSTR-3B only)

Total Late Fee

₹—

Enter due date and filing date

Total Penalty + Interest

₹—

Late fee + 18% interest

Days Delayed

—

From due date

Interest (18% p.a.)

₹—

On unpaid tax

CGST Late Fee

₹—

Central component

SGST Late Fee

₹—

State component

Select GSTR type and enter dates to calculate penalty.

Original Tax Amount

₹—

Unpaid liability

Total Payable

₹—

Tax + penalty + interest

Live Result Illustration

Visual summary — updates instantly as you enter values above

LIVE

Real-Life Guide to Using the GST Late Fee

Penalty for late GSTR filing. Use the examples and checks below to turn the number into a practical decision.

When this calculator is useful

Registered taxpayers who missed the due date for filing GSTR-1 or GSTR-3B use this to estimate the late fee and interest accumulating per day before they file, so they know the amount to pay along with the pending return.

For most people, the best way to use the GST Late Fee is to try the real case first, then change one input at a time. That makes the trade-off visible. For example, with a loan calculator you can change tenure while keeping the same rate; with an investment calculator you can change return assumption while keeping the same monthly contribution; with a health, education or measurement calculator you can check how much one input changes the final category.

The result should answer a practical question: Can I afford this? How much should I save? Is this score enough? Is this measurement within range? What is the safer or cheaper option? If the output does not answer the decision clearly, adjust the inputs until the scenario matches your real situation.

Real-Life Example

Small business filing GSTR-3B late: A small business with ₹15,000 in tax liability files its GSTR-3B 20 days after the due date, not a nil return.

1At an illustrative combined late fee rate (CGST + SGST together) of around ₹50-100 per day depending on the return type, 20 days of delay adds roughly ₹1,000-₹2,000 in late fee, plus interest under Section 50 on the ₹15,000 unpaid tax at the applicable annual rate calculated for those 20 days — confirm the exact current per-day rate on the GST portal before paying.

2Now change one input, such as rate, time, quantity, unit or score, and compare the new result with the first one.

Both late fee and interest accrue daily from the due date, so filing even a few days sooner meaningfully reduces the total amount owed compared to waiting.

Practical Advice

Use the GST Late Fee as a planning tool, not just a number generator. Write down the inputs you used, because the final answer is meaningful only when you remember the assumptions behind it.

If the decision affects money, health, tax, safety, academics or legal compliance, keep a second check ready. That second check may be a bank quote, payslip, official rule, prescription, site measurement, mark sheet or invoice.

Common Mistakes

Forgetting that late fee is charged per day of delay separately for CGST and SGST, so the commonly quoted per-day figure needs to be doubled to get the actual total daily late fee
Not distinguishing between the reduced late fee for a nil return (where there was no outward supply to report) and the higher late fee that applies once there is actual tax liability in the return
Confusing late fee (a fixed penalty for late filing) with interest under Section 50 (charged on the tax amount actually outstanding), which are calculated separately and both apply if tax is unpaid and the return is late
Not accounting for the maximum cap on late fee per return, which prevents the per-day amount from growing indefinitely no matter how many months pass
Assuming the late fee for the annual return (GSTR-9) works the same way as monthly returns like GSTR-3B — annual return late fees follow a separate structure often linked to turnover

How to Interpret Results

The result shows the accumulated late fee (and interest, if tax was also unpaid) up to the date you plan to file — file as soon as possible after checking this, since both figures keep growing for every additional day of delay up to the applicable cap.

A good interpretation looks at both the main result and the supporting values. If a page shows totals, ratios, categories, schedules or warnings, read those together instead of focusing only on the biggest number.

GST Late Fee FAQs

Useful answers for interpreting the output, avoiding mistakes and using the result responsibly.

What exactly does this calculator estimate?

It estimates the late fee for filing a GST return (like GSTR-1 or GSTR-3B) after its due date, based on the number of days delayed, and can separately estimate interest on any tax amount that remained unpaid past the due date.

Is late fee the same as interest on unpaid GST?

No, they are two different charges. Late fee under Section 47 is a fixed per-day penalty charged for filing the return itself late, regardless of whether tax was due, while interest under Section 50 is charged specifically on the tax amount that was paid late, calculated as a percentage per annum for the number of days of delay.

Why is the late fee lower on my nil return than what this calculator shows for a normal return?

GST rules provide for a reduced late fee for nil returns — where a taxpayer had no outward supplies and no tax liability to report for the period — compared to returns that do carry an actual tax liability, so make sure you have selected "nil return" in the calculator if that applies to your filing.

Is there a maximum cap on how much late fee I can be charged?

Yes, the late fee per return is generally capped at a maximum amount (which has been revised and reduced by government notifications over time, and differs for nil versus non-nil returns), so the per-day fee does not grow without limit even after a very long delay — check the current notified cap rather than assuming an old figure.

Does this calculator apply to the annual GST return (GSTR-9) as well?

Late fee for GSTR-9, the annual return, follows a separate per-day structure and cap that is often linked to the taxpayer's aggregate turnover, unlike the flat structure for monthly returns like GSTR-3B — use a version of the calculator or reference that specifically covers annual return late fees rather than the monthly-return figures.

I have multiple months of pending GSTR-3B — should I file them all together?

Each pending month's return accrues its own late fee and interest independently from its own due date, so filing older months does not reduce the fee already accumulated on them; the calculator should be run separately for each pending period to get an accurate total across all of them.

Does the GST portal show the exact same amount as this calculator when I actually file?

The GST portal auto-calculates the late fee and interest at the time of filing based on the exact number of days elapsed up to that moment and the rates in force, so treat this calculator as a close estimate for planning how much to keep ready, and rely on the portal's own computation as final at the point of actual filing.

What should I do if I can't pay the full late fee and tax right now?

Filing the return as soon as possible is still important even if full payment is delayed further, since late fee for non-filing continues to accrue and can also affect your ability to file subsequent periods' returns; consult a GST practitioner about any available relief scheme or payment approach for outstanding dues.

GST Late Fee & Interest Rules

GST late fees apply when returns are filed after the due date. The fee is charged per day of delay, up to a specified cap per return type. For GSTR-3B, interest at 18% p.a. also applies on unpaid tax from the due date to the actual payment date.

NIL returns (no tax, no transactions) attract lower late fees — ₹20/day capped at ₹500. Regular returns attract ₹50/day for most return types. GSTR-9 (annual return) has a higher ₹200/day fee but capped at 0.25% of annual turnover.

Example Calculation

Scenario: GSTR-3B due 20 Aug, filed 15 Sep (26 days late), ₹50,000 tax unpaid

1Late fee = ₹50/day × 26 = ₹1,300 (CGST ₹650 + SGST ₹650)

2Interest = ₹50,000 × 18% / 365 × 26 = ₹643

3Total payable = ₹50,000 + ₹1,300 + ₹643 = ₹51,943

✓ Total penalty = ₹1,943 (late fee ₹1,300 + interest ₹643)

Frequently Asked Questions

GST late fees and interest explained

What is the late fee for GSTR-3B?

GSTR-3B late fee is ₹50/day (₹25 CGST + ₹25 SGST) for returns with tax liability, capped at ₹10,000 total (₹5,000 CGST + ₹5,000 SGST). For nil returns, it's ₹20/day capped at ₹500. Plus 18% p.a. interest applies on unpaid tax from the original due date.

Is there interest on GSTR-1 late filing?

No. GSTR-1 is a declaration return, not a payment return — so no interest is charged for late filing of GSTR-1. Only late fee applies: ₹50/day capped at ₹10,000 for regular returns, ₹20/day capped at ₹500 for nil returns.

What is the GSTR-9 late fee cap?

GSTR-9 (annual return) attracts ₹200/day (₹100 CGST + ₹100 SGST), but is capped at 0.25% of annual turnover. For a turnover of ₹50 lakh, the maximum fee is ₹12,500. GSTR-9 is mandatory for businesses with turnover above ₹2 crore.