A common panic among accountants occurs right after hitting the file button: an invoice was omitted from outward supplies, tax was entered under CGST instead of IGST, or excess input tax credit was declared in Table 4. Because there is no revise button on the GST portal, attempting to undo a filed return is impossible. The statute provides a specific mechanism to correct these figures without facing adverse department action.
Statutory mechanism for correcting GSTR-3B
Unlike income tax returns, the GST framework does not provide for a revised return. Instead, Section 39(9) of the CGST Act establishes that if a registered person discovers any omission or incorrect particulars in a return furnished under Section 39, they must rectify the mistake in the return to be furnished for the tax period during which the error is noticed.
As confirmed in the GSTN Portal User Guide, Form GSTR-3B once filed cannot be revised. Adjustments in outward liability or input tax credit must be reported in the return for a subsequent tax period or discharged separately via Form GST DRC-03. For a detailed breakdown of how return structures link together, see our guide on GSTR-3B meaning, format and how GSTR-2B feeds it.
Statutory cut-off date: Under the proviso to Section 39(9), no rectification of errors or omissions is permitted after 30 November following the end of the financial year to which such details pertain, or the actual date of filing the relevant annual return under Section 44, whichever is earlier.
Correction procedures by error category
How you adjust your figures depends on whether the mistake involves under-reported liability, over-reported liability, excess credit claimed, or short credit availed.
1. Under-reported outward liability
If you declared lower turnover or paid less tax than actuals in Table 3.1:
- Option A (Next GSTR-3B): Add the differential turnover and tax liability to Table 3.1(a) of your next GSTR-3B. Calculate interest under Section 50(1) of the CGST Act at 18 percent per annum from the day succeeding the original due date until the actual date of payment, and declare it in Table 5.1.
- Option B (Form GST DRC-03): If the amount is significant and you do not wish to wait for the next return due date, discharge the differential tax plus interest immediately via Form GST DRC-03 by selecting voluntary payment on the GST portal as outlined in the GSTN DRC-03 User Guide.
2. Over-reported outward liability
If you declared excess liability and paid surplus tax in cash or credit:
- Adjustment in subsequent return: Reduce your outward tax liability in Table 3.1 of the subsequent GSTR-3B return, provided you have sufficient outward tax liability in that period to absorb the negative adjustment.
- Refund claim: If outward supplies in subsequent periods are insufficient to absorb the excess payment, file an application for refund of excess tax paid in Form GST RFD-01 on the GST portal under Section 54.
3. Excess input tax credit availed
If you claimed more ITC in Table 4 than was available in your purchase register or auto-populated GSTR-2B:
- Report the reversal in Table 4(B)(2) (Others) of your next GSTR-3B.
- Verify whether the excess credit was utilised. Under Section 50(3) of the CGST Act read with Rule 88B(3), interest at 18 percent per annum is applicable only if the wrongly availed credit was also utilised to pay output tax. If your electronic credit ledger balance never dipped below the wrongly availed amount, no interest is payable.
4. Short input tax credit availed
If you forgot to claim an eligible invoice that appears in your GSTR-2B:
- Include the omitted credit in Table 4(A)(5) (All other ITC) of your subsequent GSTR-3B return.
- Ensure the credit is claimed within the time limit under Section 16(4) of the CGST Act, which is 30 November following the end of the financial year or the date of furnishing the annual return, whichever is earlier.
Worked example: rectifying tax under-reporting with interest
A registered manufacturing firm in Maharashtra discovered an omission in its filed return for July 2026. An intra-state outward invoice of ₹1,00,000 taxable value at 18 percent GST (₹9,000 CGST and ₹9,000 SGST) was omitted from GSTR-3B filed on 20 August 2026. The accountant rectifies the mistake in the August return filed on 20 September 2026.
| Particulars | Declared in July return | Actual figures | Differential adjustment in August |
|---|---|---|---|
| Taxable value | ₹10,00,000 | ₹11,00,000 | ₹1,00,000 |
| CGST (9%) | ₹90,000 | ₹99,000 | ₹9,000 |
| SGST (9%) | ₹90,000 | ₹99,000 | ₹9,000 |
| Delay period | Due date: 20 Aug 2026 | Paid on: 20 Sep 2026 | 31 days delay |
| Interest payable (18% p.a.) | ₹0 | ₹275 | ₹275 (₹137.50 CGST + ₹137.50 SGST) |
Interest calculation formula under Section 50(1):
Interest = Tax liability × (18 / 100) × (Number of days delay / 365)
For CGST: ₹9,000 × 0.18 × (31 / 365) = ₹137.51 (rounded to ₹137.50). Total interest across CGST and SGST equals ₹275.00, reported in Table 5.1 of the August GSTR-3B.
Summary of error types and solutions
| Error type | Where to correct | Interest applicable | Statutory reference |
|---|---|---|---|
| Outward liability under-reported | Table 3.1 of next GSTR-3B or Form GST DRC-03 | Yes, 18% per annum from due date | Section 39(9), Section 50(1) |
| Outward liability over-reported | Reduce Table 3.1 in next return or Form GST RFD-01 | No | Section 39(9), Section 54 |
| Excess ITC availed and utilised | Table 4(B)(2) reversal in next GSTR-3B | Yes, 18% per annum under Rule 88B | Section 50(3), Circular 170/02/2022-GST |
| Excess ITC availed but unutilised | Table 4(B)(2) reversal in next GSTR-3B | No interest if ledger balance remained intact | Section 50(3) proviso |
| Omitted ITC from GSTR-2B | Table 4(A)(5) in next GSTR-3B | No | Section 16(4) cut-off |
Frequently asked questions
Can I revise a filed GSTR-3B return?
No. The GST portal does not allow revision of a filed Form GSTR-3B. Any omission or incorrect entry must be adjusted in the return for a subsequent tax period or discharged via Form GST DRC-03.
What is the time limit to rectify errors in GSTR-3B?
Under the proviso to Section 39(9) of the CGST Act, no rectification of any omission or incorrect particulars is allowed after 30 November following the end of the financial year, or the actual date of filing the relevant annual return, whichever is earlier.
How do I correct under-reported liability in GSTR-3B?
You can add the differential taxable value and tax liability in Table 3.1 of your next GSTR-3B return along with applicable interest under Section 50(1), or discharge it immediately through Form GST DRC-03 under voluntary payment.
What happens if I claimed excess ITC in GSTR-3B?
You must reverse the excess credit in Table 4(B) of a subsequent GSTR-3B return. If the excess credit was also utilised against tax liabilities, interest at 18 percent per annum is payable under Section 50(3).
Check your purchase register against GSTR-2B before filing
Preventing ITC errors before submission avoids painful GSTR-3B adjustments and interest calculations. Our free browser tool matches invoices across thousands of rows in seconds. Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
Last checked: 24 October 2026. Sources: CBIC Tax Information Portal (CGST Act Section 39), GSTN Portal User Manual (Form GST DRC-03).