What is GST interest under Section 50?

GST interest is the penalty charged for late payment of GST or for claiming excess Input Tax Credit. Under Section 50(1) of the CGST Act, interest at 18% per annum is charged on the net tax liability paid after the due date. Under Section 50(3), interest at 24% per annum is charged on ITC that was wrongfully claimed and utilized.

What is the difference between GST interest and GST late fee?

GST interest and GST late fee are two separate penalties. GST interest under Section 50 is a percentage-based charge (18% or 24% per annum) calculated on the tax amount for delayed payment. GST late fee under Section 47 is a fixed daily charge (Rs 50 per day for GSTR-3B, Rs 25 CGST + Rs 25 SGST) for late filing of GST returns, regardless of tax amount. Both can apply simultaneously if you file late and also pay tax late.

Is GST interest calculated on gross or net tax liability?

Since the amendment effective from September 1, 2020, GST interest under Section 50(1) is calculated on the net tax liability. This means interest is charged only on the tax amount payable in cash (after adjusting Input Tax Credit), not on the gross tax liability. This was a significant relief for taxpayers who had sufficient ITC but filed returns late.

What is the due date for GSTR-3B filing?

The due date for GSTR-3B filing depends on your aggregate turnover. For businesses with turnover above Rs 5 crore, it is the 20th of the following month. For businesses with turnover up to Rs 5 crore, it is the 22nd or 24th of the following month depending on the state. For example, GSTR-3B for June 2026 would be due on July 20, 2026 for large taxpayers.

Can GST interest be waived?

GST interest cannot be waived under normal circumstances. It is a statutory liability under Section 50 of the CGST Act. However, the government has occasionally provided relief through notifications during special circumstances such as the COVID-19 pandemic, where interest was reduced or waived for specific periods. In regular situations, you must pay the full interest amount along with the delayed tax payment.

What happens if I do not pay GST interest?

If you do not pay GST interest along with the delayed tax payment, the tax authorities can recover the amount through various enforcement measures. These include attaching and selling your movable and immovable property, recovering from your bank accounts, or issuing a garnishee order to your debtors. The interest amount also continues to accrue until full payment is made.

Is GST interest applicable on reverse charge mechanism?

Yes, GST interest under Section 50(1) at 18% per annum applies to late payment of GST under the reverse charge mechanism. If you are liable to pay GST under reverse charge (for example, on certain services or goods from unregistered dealers) and fail to pay by the due date, interest will be charged on the delayed amount from the due date to the actual date of payment.

How do I pay GST interest on the GST Portal?

GST interest is paid through the GST Portal while filing your GSTR-3B return. In the GSTR-3B form, there is a separate column for interest in Table 5.1. You need to calculate the interest amount manually and enter it in the interest column. The interest is paid along with the tax payment through electronic cash ledger. You cannot use ITC to pay interest; it must be paid in cash.

Does GST interest apply to nil returns filed late?

No, GST interest does not apply to nil returns filed late. Since there is no tax liability in a nil return, there is no base amount on which interest can be calculated. However, GST late fee under Section 47 still applies for filing nil returns after the due date. The late fee for nil GSTR-3B is Rs 20 per day (Rs 10 CGST + Rs 10 SGST), capped at Rs 500 per return.

GST Interest Calculator | Free Online GST Interest Calculator India

Q: How is GST interest calculated?

GST interest is calculated using the formula: Interest = (Tax Amount x Interest Rate x Number of Days Delayed) / 365. For late payment, the rate is 18% per annum on net tax liability. For excess ITC claimed and utilized, the rate is 24% per annum. The number of days is counted from the day after the due date to the actual date of payment.

What is GST Interest?

GST interest is the penalty charged by the government when a taxpayer fails to pay GST on time or claims and utilizes excess input tax credit. It is governed by Section 50 of the Central Goods and Services Tax (CGST) Act, 2017.

There are two scenarios where GST interest applies:

Section 50(1): Interest at 18% per annum is charged when a registered person fails to pay GST by the due date. This applies to the net tax liability, meaning the amount payable in cash after adjusting available input tax credit
Section 50(3): Interest at 24% per annum is charged when a registered person claims and utilizes excess or undue input tax credit. This higher rate acts as a deterrent against wrongful ITC claims
Interest is calculated from the day after the due date up to the actual date of payment, on a daily basis
GST interest must be paid in cash through the electronic cash ledger. It cannot be paid using input tax credit

How is GST Interest Calculated?

GST interest is calculated using a simple formula based on the tax amount, applicable interest rate, and the number of days of delay. The calculation is straightforward once you identify the correct interest rate and delay period.

Interest = (Tax Amount x Rate x Days Delayed) / 365

Here is the step-by-step process:

Step 1: Identify whether it is a late payment case (Section 50(1) at 18%) or excess ITC case (Section 50(3) at 24%)

Step 2: Determine the net tax liability payable in cash (for late payment) or the excess ITC amount claimed (for excess ITC)

Step 3: Calculate the number of days delayed from the day after the due date to the actual date of payment

Step 4: Apply the formula: (Amount x Rate x Days) / 365

Step 5: Pay the interest amount along with the tax through your GST calculator computation in GSTR-3B

Since the September 2020 amendment, interest under Section 50(1) is calculated on the net tax liability only. This means if you have sufficient ITC but filed your return late, interest is charged only on the cash component of the tax payment, not the entire gross liability.

GST Interest Calculation with Example

Let us walk through two practical examples to understand how GST interest is computed in different scenarios.

Example 1: Late Payment of GST

Scenario: A restaurant owner has a net GST liability of ₹2,00,000 for June 2026. The GSTR-3B due date is July 20, 2026, but the payment is made on August 15, 2026.

Days Delayed: July 21 to August 15 = 26 days

Interest Rate: 18% per annum (Section 50(1))

Interest = (2,00,000 x 18% x 26) / 365

Interest = (2,00,000 x 0.18 x 26) / 365

Interest = 9,36,000 / 365 = ₹2,564

The restaurant owner must pay ₹2,564 as interest along with the delayed GST payment of ₹2,00,000.

Example 2: Excess ITC Claimed

Scenario: A business claimed ₹5,00,000 as ITC but was eligible for only ₹3,50,000. The excess ITC of ₹1,50,000 was utilized. The excess was identified after 90 days.

Excess ITC Amount: ₹1,50,000

Interest Rate: 24% per annum (Section 50(3))

Interest = (1,50,000 x 24% x 90) / 365

Interest = (1,50,000 x 0.24 x 90) / 365

Interest = 32,40,000 / 365 = ₹8,877

The business must reverse the excess ITC of ₹1,50,000 and pay ₹8,877 as interest.

GST Interest Rates Under Section 50

The CGST Act prescribes different interest rates depending on the nature of the default. Understanding which rate applies is critical for accurate interest computation.

Scenario	Section	Interest Rate
Late payment of GST (tax paid after due date)	Section 50(1)	18% per annum
Excess ITC claimed and utilized	Section 50(3)	24% per annum
Reduction in output tax liability (refund situation)	Section 56	6% per annum

The 18% rate under Section 50(1) applies to most common scenarios where businesses file their GSTR-3B late or pay GST after the due date. The higher 24% rate under Section 50(3) is specifically for cases where ITC was wrongfully claimed and utilized. If you only claimed excess ITC but did not utilize it (it remained in your electronic credit ledger), the 24% rate does not apply.

Difference Between GST Interest and GST Late Fee

Many taxpayers confuse GST interest with GST late fee, but they are two distinct penalties that can apply simultaneously. Understanding the difference helps you calculate your total liability accurately.

Parameter	GST Interest (Section 50)	GST Late Fee (Section 47)
Nature	Percentage-based charge on tax amount	Fixed daily charge for late return filing
Rate	18% or 24% per annum	₹25 CGST + ₹25 SGST per day
Calculated on	Net tax liability or excess ITC amount	Per day of delay in filing (not tax amount)
For nil returns	Not applicable (no tax liability)	₹10 CGST + ₹10 SGST per day (max ₹500)
Maximum cap	No cap (accrues until payment)	Capped at ₹5,000 per return
Payment method	Cash only (electronic cash ledger)	Cash only (electronic cash ledger)

Use our GST late fee calculator to compute the fixed daily charge separately. When you file a belated GSTR-3B with tax liability, you will owe both the late fee (for late filing) and interest (for late tax payment). Plan your GST payments using a reverse GST calculator to ensure you set aside the correct amount on time.

How to Use This GST Interest Calculator

This free GST interest calculator computes the exact interest payable under Section 50 of the CGST Act. Follow these steps to get your result:

Step 1: Select the interest type. Choose "Late Payment" if you paid GST after the due date (18% p.a.), or "Excess ITC" if you claimed and utilized more ITC than eligible (24% p.a.)
Step 2: Enter the tax amount. For late payment, enter the net tax liability payable in cash (after adjusting ITC). For excess ITC, enter the excess ITC amount that was wrongfully utilized
Step 3: Enter the due date. This is typically the GSTR-3B filing due date for the relevant tax period (20th, 22nd, or 24th of the following month depending on your turnover)
Step 4: Enter the actual payment or filing date. This is the date when you actually paid the GST or filed the return
Step 5: Optionally enter your GSTIN for inclusion in the downloadable PDF report
Step 6: Click "Calculate Interest" to see the total interest payable, days delayed, interest rate, and daily interest amount

Download the PDF report for a detailed breakdown including month-wise interest computation, formula applied, and GSTR-3B filing reference. Businesses can streamline their GST compliance through Petpooja Invoice, which handles invoice generation and GST computation automatically.

How to Avoid GST Interest Penalties

Paying GST interest increases your compliance cost and affects cash flow. Here are practical steps to avoid interest penalties altogether:

Set up calendar reminders: Mark the GSTR-3B due dates (20th, 22nd, or 24th of each month) on your calendar. File and pay at least 2 to 3 days before the deadline to account for bank processing delays
Maintain sufficient cash balance: Keep a dedicated GST fund in your business account. Transfer the estimated GST liability from daily collections into this fund regularly
Reconcile ITC monthly: Match your purchase invoices with GSTR-2B before filing returns. Claiming only eligible ITC prevents the 24% interest penalty under Section 50(3)
Use accounting software: Automated invoicing and GST computation tools reduce manual errors and ensure timely filing. They also send reminders before due dates
File nil returns on time: Even if there is no tax liability, file your nil GSTR-3B before the due date. While nil returns do not attract interest, they do attract late fees
Verify GSTIN of suppliers: Before claiming ITC, verify that your suppliers have valid GSTINs and have filed their returns. ITC claimed on non-compliant suppliers may be reversed later, attracting the 24% interest rate

GST Interest Calculator