Due Dates
GSTR-1 (Monthly): 11th of every monthGSTR-3B (Monthly): 20th of every monthITR Filing (Individuals): 31st July 2026AOC-4 (ROC Annual Filing): 30th October 2026MGT-7 (ROC Annual Return): 29th November 2026
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GST Interest Calculator

Instantly calculate interest on delayed GST payments under Section 50 of the CGST Act. Know your exact liability for late filing or excess ITC claims.

Enter Details

₹
₹1,000₹1 Cr

Interest Summary

GST Amount Due₹1,00,000.00
Days Delayed26 days
Interest Rate18% p.a.
Interest Payable₹1,282.19
Total Amount Payable₹1,01,282.19

Calculation Breakdown

1

Due Date: 20 Aug 2026

2

Interest starts from: 21 Aug 2026 (day after due date)

3

Payment Date: 15 Sept 2026

4

Delay Period: 26 days

Formula

Interest = Tax × Rate × Days ÷ 365

= ₹1,00,000.00 × 18% × 26 ÷ 365

= ₹1,282.19

Understanding GST Interest

What is GST Interest?

GST interest is a statutory charge levied under Section 50 of the Central Goods and Services Tax (CGST) Act, 2017 when a registered taxpayer fails to pay the Goods and Services Tax within the prescribed due date. It serves as compensation to the government for the delayed receipt of tax revenue.

Unlike penalties or late fees, GST interest is automatically applicable the moment a payment deadline is missed ”” no separate notice or assessment order is required. The interest is calculated on a simple interest basis from the day after the due date until the actual date of payment, and must be paid in cash through the electronic cash ledger. It cannot be set off against Input Tax Credit.

The amount of interest depends on two factors: the nature of the default (late payment vs. excess ITC) and the number of days the payment is delayed. Taxpayers are expected to self-assess and pay the interest voluntarily while filing their returns.

Applicability

When is GST Interest Applicable?

⏰

Late Payment of GST

When you file GSTR-3B after the due date and pay the tax liability late, interest at 18% p.a. applies on the net tax amount from the day after the deadline until the date of actual payment.

⚠️

Excess ITC Claimed & Utilised

If you claim more Input Tax Credit than you are legitimately entitled to and use it to reduce your output tax liability, a higher interest rate of 24% p.a. is charged on the excess ITC amount.

🔄

Undue Reduction of Output Tax

When the output tax liability is wrongly reduced through incorrect reporting, misclassification of supplies, or wrong tax rate application, interest at 24% p.a. is levied on the shortfall amount.

Rate Details

GST Interest Rates

18%

Late Payment

Section 50(1) ”” CGST Act

  • ●Applies when GST is paid after the return due date
  • ●Calculated on net tax liability (after ITC adjustment)
  • ●Covers CGST, SGST/UTGST, and IGST components separately
  • ●Most common scenario faced by taxpayers
24%

Excess ITC / Undue Claim

Section 50(3) ”” CGST Act

  • ●Applies when excess ITC is claimed and utilised
  • ●Applies when output tax liability is unduly reduced
  • ●Higher rate acts as a deterrent against fraudulent claims
  • ●May also attract penalty proceedings under Section 73/74
Due Dates

GST Return Due Dates

Missing these deadlines triggers automatic interest liability. Bookmark this table for quick reference.

Return TypeFrequencyDue DateApplicability
GSTR-1Monthly11th of next monthTurnover > ₹5 Cr or opted for monthly filing
GSTR-1Quarterly (IFF)13th of month after quarterTurnover ≤ ₹5 Cr under QRMP scheme
GSTR-3BMonthly20th of next monthTurnover > ₹5 Cr
GSTR-3BQuarterly22nd/24th of month after quarterTurnover ≤ ₹5 Cr under QRMP scheme
GSTR-9Annual31st December of next FYAll regular taxpayers
GSTR-9CAnnual31st December of next FYTurnover > ₹5 Cr (self-certified reconciliation)
Pro Tips

How to Avoid GST Interest

📅

Set Calendar Reminders

Mark GST return due dates at least 5 days in advance. Use digital calendar alerts for GSTR-1 and GSTR-3B deadlines every month to never miss a filing window.

📊

Maintain Regular Books

Keep your purchase and sales registers updated in real time. Monthly reconciliation of invoices with GSTR-2A/2B data helps identify mismatches early and prevents last-minute filing rushes.

💰

Maintain Sufficient Cash Balance

Ensure your electronic cash ledger has adequate funds before the due date. Deposit money at least 2–3 days before the deadline to account for bank processing delays.

🔍

Verify ITC Claims Carefully

Cross-check every ITC claim against GSTR-2B auto-populated data. Avoid claiming credit on ineligible items listed under Section 17(5) such as personal vehicles, food, and outdoor catering.

🤝

Hire a Professional

Engage a qualified GST practitioner or chartered accountant to handle your compliance. Professional oversight significantly reduces the risk of errors, wrong ITC claims, and missed deadlines.

🔧

Use GST-Compliant Software

Adopt accounting software that auto-generates GST returns, tracks due dates, and flags discrepancies. Automated tools eliminate manual errors and streamline your entire filing process.

Step-by-Step

How to Use This Calculator

01

Enter the GST Amount Due

Type the outstanding tax amount or use the slider to set a value between ₹1,000 and ₹10 Crore. You can also select from preset amounts for quick input.

02

Select the Due Date

Choose the original due date for your GST return (e.g., 20th of the month for GSTR-3B). This is the deadline by which the tax should have been paid.

03

Enter the Payment Date

Select the actual date on which you paid or plan to pay the outstanding GST amount. The calculator computes interest from the day after the due date up to this date.

04

Choose the Interest Type

Select "Late Filing" for standard delayed payments (18% p.a.) or "Excess ITC Claimed" for cases where excess Input Tax Credit was claimed and utilised (24% p.a.).

05

Review Your Results

The calculator instantly displays the number of delay days, applicable interest rate, computed interest amount, and total payable. A step-by-step breakdown shows exactly how the interest was calculated.

Got Questions?

Frequently Asked Questions

How is GST interest calculated?
GST interest is calculated on the outstanding tax amount from the day after the due date until the actual date of payment. The formula is: Interest = Tax Amount × Rate × Number of Days / 365. The rate is 18% p.a. for late payment and 24% p.a. for excess ITC claimed.
What is the interest rate for late filing of GST returns?
Under Section 50(1) of the CGST Act, interest at the rate of 18% per annum is charged on the net tax liability when GST is paid after the due date. This applies to both GSTR-3B and GSTR-1 late filings.
When is 24% interest applicable under GST?
A 24% per annum interest rate applies under Section 50(3) of the CGST Act when a registered person claims excess Input Tax Credit (ITC) or makes an undue or excess reduction in output tax liability. This higher rate serves as a deterrent against wrongful ITC claims.
Is GST interest calculated on gross or net tax liability?
Following the amendment effective from 01 September 2020, GST interest under Section 50(1) is calculated on the net tax liability ”” that is, the tax payable after adjusting eligible Input Tax Credit. This was clarified by the GST Council to reduce the burden on taxpayers.
Can GST interest be waived?
The government has the power to waive interest under Section 50 of the CGST Act in specific situations, usually through notifications during extraordinary circumstances such as natural disasters or system glitches on the GST portal. However, routine late payments do not qualify for interest waivers.
Is there any late fee in addition to GST interest?
Yes. In addition to interest, a late fee of ₹50 per day (₹25 CGST + ₹25 SGST) is charged for late filing of returns, subject to a maximum cap. For nil returns, the late fee is ₹20 per day. Interest and late fees are separate penalties and both apply simultaneously.
From which date is GST interest calculated?
Interest is calculated from the day immediately following the due date of filing the return until the actual date of payment. For example, if the GSTR-3B due date is 20th January and you pay on 15th February, interest is charged for 26 days (from 21st January to 15th February).
How do I pay GST interest on the GST portal?
GST interest is auto-calculated and shown in the return filing form. When filing GSTR-3B, the portal computes the interest based on the delay and displays it in the "Interest" column. You must pay this interest along with the tax liability before filing the return. The interest amount cannot be paid using ITC ”” it must be paid in cash.

Need Help with GST Compliance?

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