GST Interest Calculator (Section 50)

Estimate your statutory interest liability on delayed GST payments under Section 50 of the CGST Act. Compute calculations on a daily basis for both standard output tax delay (18% p.a.) and excess Input Tax Credit claims (24% p.a.).

Last Updated: June 2026•Verified By: GSTWaala Editorial Team

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Delayed Payment Details

GST Amount (₹)Enter the net tax liability paid in cash (excluding ITC utilized).

In Words: Twenty Five Thousand Rupees Only

Interest Rate (% p.a.)

* Note: 18% applies to output tax paid late. 24% applies to excess Input Tax Credit (ITC) claimed.

Auto-Calculate DaysDetermine delay days based on payment calendar dates.

Delay Start DateDate from which interest begins accruing (typically day after payment due date).

Delay End Date (Payment Date)Date when payment is actually deposited in government electronic ledger.

Assessment Report

Assessment Awaiting InputPlease correct the input errors on the left to generate the interest statement report.

How to Use the GST Interest Calculator (Section 50)

Enter your tax amount in the 'GST Amount (₹)' field. Make sure to input only your Net cash liability.
Select the applicable interest rate: Choose 18% for delayed tax payments, 24% for excess Input Tax Credit (ITC) claims, or select 'Custom' to input a custom percentage rate.
Choose whether to 'Auto-Calculate Days'. If toggled ON, select your Delay Start Date and Delay End Date. The days difference will calculate automatically.
If 'Auto-Calculate Days' is toggled OFF, enter the number of delay days manually in the field provided.
Review your calculated results instantly in the 'Assessment Report' summary card, showing total interest amount and gross payable liability.
Use the actions at the bottom to Copy the calculation breakdown, Share the URL, or Print / Save as PDF for auditing purposes.

Mathematical Formula & Calculations

Under Section 50 of the CGST Act, interest is levied on delayed payments of tax. The interest accrues daily from the day succeeding the statutory due date.

Section 50 GST Interest Formula:

\[\text{Interest} = \frac{\text{GST Amount} \times \text{Interest Rate} \times \text{Delay Days}}{365 \times 100}\]

\[\text{Total Amount Payable} = \text{GST Amount} + \text{Interest}\]

Worked Example:

If your tax amount is ₹25,000, interest rate is 18%, and payment is delayed by 45 days:

Base GST Amount = ₹25,000.00
Interest = (25,000 × 18 × 45) ÷ 36,500 = ₹554.79
Total Payable = ₹25,000.00 + ₹554.79 = ₹25,554.79

Frequently Asked Questions

GST Interest is a compensatory charge levied by the government on taxpayers who delay their tax payments past the designated statutory due dates. Under Section 50 of the CGST Act, interest is calculated on a daily basis from the day succeeding the due date until the tax is deposited.

The standard interest rate is 18% per annum for delayed payments of output tax liability. However, a higher interest rate of 24% per annum applies if a taxpayer makes an undue or excess claim of Input Tax Credit (ITC) or makes an excess reduction in output tax liability.

As per the retrospective amendment to Section 50 (effective from July 1, 2017), interest is calculated on the net tax liability paid in cash through the Electronic Cash Ledger. However, interest is charged on the gross tax liability if the return is filed late after the tax authorities initiate inspection, search, or seizure proceedings.

Yes. Delay in filing return (like GSTR-3B) implies a delay in depositing the tax liability, which triggers Section 50 interest. Additionally, late filing attracts GSTR late fees under Section 47, which is separate from interest.

The GST Council occasionally waives interest or late fees during pandemics, system outages, or economic disruptions via notifications. However, under standard conditions, interest is a statutory levy and cannot be waived voluntarily by tax officers.

Delay days are counted starting from the day immediately following the due date of payment until the date on which the tax is actually deposited in the electronic cash ledger. Both the start and end dates are included in the count.

GST interest under Section 50 is a compensatory charge for delayed tax payment calculated at 18% or 24% p.a. A GST penalty under Section 122 is a punitive measure for tax evasion, non-registration, or issuing fake invoices, and is typically a flat amount or percentage of tax evaded.

You can pay GST interest voluntarily by filing Form GST DRC-03 on the common GST portal, or you can declare and pay the interest amount in Table 5.1 of your monthly GSTR-3B return.

Yes, you can calculate it manually using the formula: Interest = (GST Cash Amount × Rate × Days) / 36500. Using our online calculator prevents mathematical rounding errors and saves time.

Yes. The GST Interest Calculator by GSTWaala is 100% free and operates fully on the client-side. No user data or financial inputs are uploaded to our servers, ensuring complete privacy.

Related Calculators

Compliance Note

All calculations are updated to reflect the tax codes, slabs, and deductions in effect for Financial Year 2025-26 (Assessment Year 2026-27). This tool runs entirely client-side; no data is transmitted or stored on our servers.

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1. What is GST Interest under Section 50 of the CGST Act?

In the Indian Goods and Services Tax (GST) regime, filing returns and paying tax liabilities on time is a core compliance requirement. If a registered taxpayer fails to pay their tax within the prescribed statutory due dates, the law levies a compensatory charge known as **GST Interest**.

This interest is governed by **Section 50 of the Central Goods and Services Tax (CGST) Act, 2017** (and corresponding provisions of SGST and IGST Acts). Unlike penalties or fines, which are punitive, interest is compensatory in nature—designed to compensate the exchequer for the delay in receiving public revenue. The liability to pay interest arises automatically under the statute and does not require a formal order from a tax officer.

2. When is GST Interest Applicable?

GST Interest becomes applicable under three primary conditions:

Delayed Payment of Output Tax: When a taxpayer files their monthly or quarterly returns (such as GSTR-3B) after the designated due date, the payment of tax is delayed, triggering interest under Section 50(1).
Short Payment or Non-Payment: When a taxpayer under-reports their output tax liability in GSTR-3B and pays less tax than actually due, interest is charged on the unpaid difference from the original due date.
Excess Claim of Input Tax Credit (ITC): Under Section 50(3), if a taxpayer claims more ITC in GSTR-3B than they are eligible for, and subsequently utilizes that excess ITC to offset output liabilities, they must pay interest on the utilized excess credit.

3. The GST Interest Rate Structure (18% vs 24% p.a.)

The interest rate levied on delayed payments varies based on the nature of the delay:

Legal Provision	Interest Rate	Nature of Default	Calculation Basis
Section 50(1)	18% per annum	Delayed payment of output tax liability (declared in returns).	Charged on net cash tax liability on daily basis.
Section 50(3)	24% per annum	Undue or excess claim of Input Tax Credit (ITC) which is utilized.	Charged on the utilized excess ITC from date of utilization till reversal.

* Note: Under the Finance Act 2022, the interest rate for utilized excess ITC under Section 50(3) was retrospectively capped at 20% (or up to 24% as notified). Currently, notifications prescribe 18% for delayed tax and 24% for utilized excess ITC defaults.

4. The Landmark Retrospective Amendment: Net vs Gross Tax Liability

In the early years of GST, there was severe litigation regarding whether interest should be calculated on the **gross tax liability** (before utilizing ITC) or the **net tax liability** (actual cash paid).

To resolve this, the government introduced a retrospective amendment (via the Finance Act 2021, amending Section 50 of the CGST Act retrospectively from **July 1, 2017**). Under this proviso:

"Interest shall be payable only on that portion of the tax which is paid by debiting the electronic cash ledger."

This means if a taxpayer has an output liability of ₹1,00,000, utilizes ₹80,000 from Input Tax Credit, and pays the balance ₹20,000 in cash:

No Interest applies to the ₹80,000 settled via input credit (since this tax was already in the government exchequer).
Interest is calculated only on the ₹20,000 paid through the Electronic Cash Ledger.

Exception to the Net Rule:

If a taxpayer fails to file GSTR-3B, and tax payment is delayed, and subsequently the tax authorities detect the delay through search, inspection, or demand proceedings (Section 73 or 74), the interest will be levied on the **gross tax liability** instead of the net cash amount.

5. Detailed Worked Examples

Example Case 1: Moderate Business Tax Delay

GST Cash liability: ₹25,000
Delay days: 45 days
Applicable rate: 18% p.a.
Calculation:
Interest = (25,000 × 18 × 45) ÷ 36,500 = ₹554.79
Total Amount due: ₹25,000 + ₹554.79 = ₹25,554.79

Example Case 2: Larger Liability / Long Delay

GST Cash liability: ₹1,20,000
Delay days: 120 days
Applicable rate: 18% p.a.
Calculation:
Interest = (1,20,000 × 18 × 120) ÷ 36,500 = ₹7,101.37
Total Amount due: ₹1,20,000 + ₹7,101.37 = ₹1,27,101.37

6. GSTR Late Filing Fees vs GST Interest

Many taxpayers confuse late filing fees with interest. They are separate charges under different sections of the GST Act:

GST Late Fee (Section 47): Charged for delay in filing the return document (like GSTR-1 or GSTR-3B). It is a flat daily fee (e.g. ₹50/day for standard tax returns, capped at statutory limits) regardless of your tax liability. Even Nil returns attract a late fee (typically ₹20/day).
GST Interest (Section 50): Charged for delay in depositing the actual tax cash. It depends entirely on the tax amount and the duration of delay. If your tax liability is zero (Nil return), **no interest** will accrue under Section 50, even if the return is filed months late.

7. Common Compliance Errors to Avoid

To avoid audit objections and demands from the GST Department, keep the following practices in mind:

Do Not Offset Output Tax with Unearned ITC: Do not claim credit in GSTR-3B before receiving goods or invoice copies. If you utilize unearned ITC, interest at 24% p.a. will be levied under Section 50(3) upon reversal.
Voluntary Interest Payment: Do not wait for the tax department to issue a show-cause notice (SCN) or demand letter. Interest is a self-assessed liability. Pay it voluntarily through GSTR-3B or DRC-03 to prevent additional penalties.
Check Calendar Days Correctly: Interest is calculated daily. Ensure you calculate the exact difference between the date when tax was due and the date when the challan was paid.