GSTR-3B Interest Calculator
Interest on a late GSTR-3B payment — 18% a year on tax paid late (24% for excess ITC claimed), counted per day of delay.
What this GSTR-3B Interest Calculator does
Under the Goods and Services Tax (GST) framework, missing the statutory filing deadline for Form GSTR-3B triggers two distinct financial liabilities: a fixed daily Late Fee under Section 47 of the CGST Act, and mandatory Interest on delayed tax discharge under Section 50. While late fees are automatically capped and debited on the portal, interest continues to accrue daily until the tax is settled in full.
This calculator computes exact interest liability under Section 50 using statutory daily proration across both notified rate regimes: 18% per annum for regular delayed tax payment, and 24% per annum for wrongly availed and utilized Input Tax Credit (ITC).
The Net Cash Liability Rule (Rule 88B)
A critical statutory safeguard under GST law is that interest on delayed GSTR-3B filing is levied strictly on Net Cash Liability, not Gross Tax Liability. Pursuant to the proviso to Section 50(1) and Rule 88B of the CGST Rules, if a return is filed after the due date, interest is payable only on that portion of the tax that is paid by debiting the Electronic Cash Ledger.
Any output tax liability settled by utilizing valid Input Tax Credit (ITC) from the Electronic Credit Ledger attracts zero interest, provided sufficient credit balance was available on the statutory due date. Therefore, when using this calculator, enter only the cash-ledger portion of your unpaid tax liability.
Section 50 Interest Formulation
Interest = Net Cash Tax Liability × (Rate ÷ 100) × (Days of Delay ÷ 365)
- Net Cash Tax Liability: Tax discharged via Electronic Cash Ledger (after utilizing available ITC)
- Rate: 18% p.a. for delayed payment under Section 50(1); 24% p.a. for wrongly availed & utilized ITC under Section 50(3)
- Days of Delay: Number of calendar days counted from the day immediately following the statutory due date up to and including the date of payment
- Compounding: None. Section 50 levies simple interest calculated on a strict 365-day annual basis
Worked example: Delayed Tax Discharge of ₹1,00,000
Consider a registered taxpayer with an output cash liability of ₹1,00,000 for April 2025 (due date May 20, 2025) who files GSTR-3B and discharges tax 30 days late on June 19, 2025:
- Tax paid via Cash Ledger: ₹1,00,000
- Applicable interest rate: 18% per annum
- Days of delay: 30 days
- Interest accrued: ₹1,00,000 × (18 ÷ 100) × (30 ÷ 365) = ₹1,479.45
- Total amount payable to clear liability: ₹1,00,000 + ₹1,479.45 = ₹1,01,479.45
If the same delay involved ₹1,00,000 of wrongly claimed and utilized ITC under Section 50(3) at 24% p.a., the interest liability increases to ₹1,972.60.
Interest on ₹1,00,000 Delayed Cash Tax Across Tenures
| Days of Delay | Interest at 18% p.a. (Delayed Tax) | Interest at 24% p.a. (Wrong ITC) | Total Payable (at 18%) |
|---|---|---|---|
| 15 Days | ₹739.73 | ₹986.30 | ₹1,00,739.73 |
| 30 Days | ₹1,479.45 | ₹1,972.60 | ₹1,01,479.45 |
| 60 Days | ₹2,958.90 | ₹3,945.21 | ₹1,02,958.90 |
| 90 Days | ₹4,438.36 | ₹5,917.81 | ₹1,04,438.36 |
| 180 Days | ₹8,876.71 | ₹11,835.62 | ₹1,08,876.71 |
| 365 Days (1 Year) | ₹18,000.00 | ₹24,000.00 | ₹1,18,000.00 |
Interest vs Section 47 Late Filing Fees
Taxpayers frequently confuse GST Interest with Late Filing Fees. They are legally independent penalties:
- Section 47 Late Fee: A statutory procedural penalty for missing return filing deadlines. For intra-state supplies, the standard late fee is ₹50 per day (₹25 CGST + ₹25 SGST) for tax liability returns, and ₹20 per day (₹10 CGST + ₹10 SGST) for Nil returns, subject to turnover-linked maximum caps (₹500 for Nil returns; ₹2,000 to ₹10,000 depending on aggregate annual turnover).
- Section 50 Interest: A financial charge on the delayed use of government revenue. Unlike late fees, interest has no maximum upper ceiling—it accrues indefinitely until the tax liability is fully remitted.
Payment Process via DRC-03 or Next GSTR-3B
Interest can be discharged through two compliant avenues on the GST Portal:
- Auto-population in Table 5.1 of Next GSTR-3B: The GST system automatically calculates interest for prior-period delays and populates Table 5.1 of your next GSTR-3B return. Taxpayers can edit and verify this figure against our calculator.
- Voluntary Payment via Form DRC-03: To stop the daily interest meter immediately without waiting for the next monthly filing cycle, taxpayers can pay accrued interest voluntarily using Form GST DRC-03 under the reason "Interest".
Frequently Asked Questions on GSTR-3B Interest
Statutory rates, net liability provisions, QRMP rules, and payment procedures.
The standard interest rate for delayed payment of output tax under Section 50(1) is 18% per annum. The higher rate of 24% per annum under Section 50(3) applies strictly when an ineligible Input Tax Credit (ITC) has been both wrongly availed AND utilized to offset tax liability. If credit was merely availed in GSTR-3B but remained unutilized in the credit ledger, zero interest is charged.
Under Rule 88B and the retrospective amendment to Section 50(1), interest on delayed return filing is levied strictly on the net cash liability discharged through the Electronic Cash Ledger. The portion of tax settled using valid balance in your Electronic Credit Ledger is exempt from interest.
A late fee is a fixed daily administrative charge (₹50/day for tax returns, ₹20/day for Nil returns) capped based on annual turnover for delayed filing. Interest is a commercial cost of 18% p.a. on the delayed tax amount, which has no upper cap and accrues daily until payment.
For regular taxpayers with annual turnover exceeding ₹5 crore, the due date is the 20th of the following month. For taxpayers enrolled under the quarterly QRMP scheme, the due date is the 22nd or 24th of the month following the quarter, depending on the state of registration.
Interest starts accruing from the day immediately following the statutory due date. For instance, if the due date is May 20 and payment is made on June 5, interest is calculated for 16 days (May 21 through June 5 inclusive).
No. While the GST Council and CBIC have historically issued notifications waiving or capping Section 47 late fees during special amnesty schemes, Section 50 interest is statutory and compensatory in nature and cannot be waived by tax authorities.
You can pay interest voluntarily at any time by generating a challan (CPIN) on the GST portal and filing Form GST DRC-03 under Section 50, selecting "Interest" as the payment cause to arrest further daily accumulation.
No. If there is no output tax liability to discharge through the cash ledger, the net cash liability is ₹0, resulting in zero interest under Section 50. However, the procedural late fee of ₹20 per day (capped at ₹500) will still apply.
Under the QRMP scheme, taxpayers must pay 35% of their net tax liability (or actual liability) in the first two months of the quarter via Form PMT-06 by the 25th of each month. Failure to pay monthly cash dues on time attracts 18% p.a. interest up to the date of actual payment or quarterly return filing.
Yes. If interest auto-populated in GSTR-3B or assessed via demand notices under Section 73/74 remains unpaid, the GST department can initiate recovery proceedings under Section 79, including issuing garnishee orders to attach business bank accounts.