GSTR-3B is the return through which a regular GST-registered business reports GST payable, claims eligible input tax credit and pays the remaining tax.
The GST portal fills in several figures automatically. Compare them with your business accounting records before filing so that missed invoices or incorrect credit do not affect your GST payment.
Who must file GSTR-3B, and when is it due?
Regular GST taxpayers file GSTR-3B monthly or quarterly, as shown below.
| Type of taxpayer | Filing requirement | Normal due date |
|---|---|---|
| Regular monthly taxpayer | One return each month | 20th of the following month |
| QRMP taxpayer in Tamil Nadu | One return each quarter | 22nd of the month following the quarter |
| QRMP taxpayer in another State or Union Territory | One return each quarter | 22nd or 24th of the following month, depending on the State group |
| Casual taxable person | Return for each applicable period | Applicable monthly deadline |
| Composition taxpayer | Does not file GSTR-3B | Separate composition forms and deadlines apply |
For example, a monthly taxpayer normally files September 2026 GSTR-3B by 20 October 2026. A Tamil Nadu QRMP taxpayer normally files the July–September 2026 return by 22 October 2026. An officially extended due date replaces the normal deadline.
Under QRMP, quarterly filing does not mean quarterly payment. For the first two months, the normal payment deadline is the 25th of the following month, where a deposit is required. Account for these deposits when settling the quarterly return.
File separately for each GSTIN. GSTR-1 reports transactions; GSTR-3B reports GST payable, credit and payment. Filing GSTR-1 alone is not enough.
Where do the automatically filled figures come from?
| Source | Information supplied |
|---|---|
| GSTR-1, including relevant IFF details under QRMP | Supplies and related GST |
| GSTR-1A, if filed | Corrections or additions made after filing GSTR-1 |
| GSTR-2B | Purchase-credit information and certain reverse-charge details |
Review these figures against your accounts. GSTR-2B may contain ineligible credit, and some reverse-charge transactions must be identified separately from your books.
Example: you discover a missed invoice
Your filed September 2026 GSTR-1 shows GST payable of ₹72,000. Before filing GSTR-3B, you discover an invoice with another ₹18,000 of GST.
Report the invoice carrying ₹18,000 GST through GSTR-1A when the facility becomes available. After filing it, check that GSTR-3B shows ₹90,000: the original ₹72,000 plus the additional ₹18,000, assuming no other changes. If the correction is already included, do not add ₹18,000 again to the GST payable in GSTR-3B.
Reporting the invoice through GSTR-1A also helps the registered customer receive its details in the next tax period’s GSTR-2B and claim eligible credit. Changing GSTR-3B alone does not report the invoice to the customer. This reduces the need to correct invoice reporting in a later period.
GSTR-1A is optional. It becomes available after filing GSTR-1 or its due date, whichever is later, and must be filed before the same period’s GSTR-3B.
How do you prepare and file GSTR-3B?
Prepare a consolidated working sheet
Collect supplies, purchases, notes, advances, reverse-charge transactions and earlier-period adjustments. Separate taxable values from GST.
For QRMP, include the whole quarter without duplicating IFF invoices. Use a consolidated GST filing Excel sheet to compare the figures.
Compare the figures and resolve differences
Match supplies and GST with GSTR-1 and any GSTR-1A changes. Compare purchase records with GSTR-2B, then review credit eligibility, reversals, reclaims and reverse-charge GST.
Identify the invoice or adjustment behind each difference. Do not change totals merely to make reports match.
Ask suppliers to report missing invoices and correct wrong details. Track invoices still awaiting action.
Review purchase invoices in the Invoice Management System, or IMS. If your actions change GSTR-2B, generate the updated statement before preparing GSTR-3B. File and pay on time while you continue following up on missing invoices.
Open the correct return and review it
Log in to the GST portal. Go to Services → Returns → Returns Dashboard, select the financial year and return period, and click Prepare Online under GSTR-3B.
Confirm the GSTIN and period, then compare each table with your working sheet. Correct differences through the available route.
Download the available summary and preview the draft return. Check taxable values, GST amounts, credit notes, debit notes, advances, amendments and credit adjustments against your consolidated Excel sheet.
If you are reporting earlier-period unpaid GST, review its period-wise breakup and related interest.
Settle the balance and complete filing
Check available credit and the cash requirement separately for CGST, SGST, IGST and cess, where applicable. Reverse-charge GST, interest and late fees require payment through the cash ledger.
Complete authentication, confirm Filed status, and save the acknowledgement and return.
A deposit or saved draft does not complete filing.
How much GST must you pay in cash?
For September 2026, assume unused credit from August 2026 and eligible September credit. All transactions are within the same State, with no reverse-charge GST or other restriction on credit use.
| Particulars | Calculation for total | CGST | SGST | Total |
|---|---|---|---|---|
| GST payable for September 2026 | Before using ITC | ₹45,000 | ₹45,000 | ₹90,000 |
| Opening ITC balance | Credit carried forward | ₹5,000 | ₹5,000 | ₹10,000 |
| ITC availed for September 2026 | Eligible credit claimed | ₹30,000 | ₹30,000 | ₹60,000 |
| Total ITC available | ₹10,000 + ₹60,000 | ₹35,000 | ₹35,000 | ₹70,000 |
| ITC utilised | Credit used towards GST | ₹35,000 | ₹35,000 | ₹70,000 |
| Closing ITC balance | ₹70,000 − ₹70,000 | ₹0 | ₹0 | ₹0 |
| GST payable through cash ledger | ₹90,000 − ₹70,000 | ₹10,000 | ₹10,000 | ₹20,000 |
| Existing cash-ledger balance | Money already deposited | ₹2,000 | ₹2,000 | ₹4,000 |
| Additional deposit needed | ₹20,000 − ₹4,000 | ₹8,000 | ₹8,000 | ₹16,000 |
You use ₹70,000 of credit and pay the remaining ₹20,000 through the cash ledger. Since ₹4,000 is already available there, you need to deposit only another ₹16,000.
Use CGST credit for CGST and SGST credit for SGST in this example. CGST and SGST credit cannot be used against each other.
The credit ledger shows unused ITC, the cash ledger shows deposited money, and the liability register shows GST payable and settled.
What information goes into the GSTR-3B tables?
| Table | What you report | Simple example |
|---|---|---|
| 3.1(a) | Taxable sales and services, other than zero-rated supplies | Goods sold or consulting services provided to a customer |
| 3.1(b) | Exports and qualifying supplies to SEZ units or developers | Goods exported under the applicable export arrangement |
| 3.1(c) | Nil-rated and exempt sales or services | A transaction covered by an applicable GST exemption |
| 3.1(d) | Purchases or services on which you must pay GST under reverse charge | Legal services received from an advocate, where your business must pay GST |
| 3.1(e) | Supplies outside GST | Sale of petrol |
| 3.1.1 | Specified supplies through an online platform where the platform pays GST | Restaurant orders covered by the platform-payment arrangement |
| 3.2 | State-wise details of certain interstate supplies to unregistered customers, composition taxpayers and UIN holders | A Tamil Nadu dealer's taxable sale to an unregistered Karnataka customer, where Karnataka is the place of supply |
| 4 | Purchase credit and its adjustments | GST on eligible business purchases, less required reversals |
| 5 | Exempt, nil-rated and non-GST purchases | Petrol purchased for business use |
| 5.1 | Interest and late fees | Interest on GST paid after its deadline |
| 6.1 | GST payment using credit and cash | Use eligible credit and pay the remaining GST in cash |
Table 3.2 gives details of supplies already included in the relevant totals; do not add them again as extra sales.
For a ₹1,00,000 invoice plus ₹18,000 GST, taxable value is ₹1,00,000, not ₹1,18,000.
For Table 4, check eligibility, deduct required reversals and include eligible reclaims. The separate guide, “GSTR-3B Input Tax Credit: Reversals, Reclaims and Ledger Effects,” will explain the detailed adjustments.
When can you file a nil GSTR-3B?
A nil return means there is nothing to report or pay: no sales or services provided, no purchases to report, no credit claim or reversal, and no GST, interest or late fee payable. There should also be no auto-filled figures or saved entries requiring reporting.
A blank screen is insufficient if your accounting records require reporting.
For example, your shop made no sales, but you paid an accountant ₹5,000 plus ₹900 GST for bookkeeping and intend to claim the eligible credit. The return is not nil because the credit must be reported.
Sales and credit must be reported even when ITC covers all GST payable.
What are the late fees and interest?
Late fees apply to delayed filing
| Return category | Normal daily late fee, CGST + SGST |
|---|---|
| Nil tax liability | ₹20 |
| Other returns | ₹50 |
| Category | Maximum late fee |
|---|---|
| Nil tax liability | ₹500 |
| Other returns: preceding financial year turnover up to ₹1.5 crore | ₹2,000 |
| Other returns: turnover above ₹1.5 crore and up to ₹5 crore | ₹5,000 |
| Other returns: turnover above ₹5 crore | ₹10,000 |
The daily rates apply from July 2017 returns onwards. Reduced caps apply from June 2021 monthly returns and the quarter ending June 2021 onwards. Official relief can change specified periods’ fees.
Assuming no special relief, a monthly return with tax liability filed 10 days late normally attracts ₹500. A quarterly return with tax liability filed 12 days late attracts ₹600; the fee is not multiplied by three. A nil-tax-liability return filed 10 days late attracts ₹200.
Where the due date is officially extended, calculate delay after the extended deadline.
Interest depends on delayed GST payment
The usual interest rate is 18% per year. For ordinary delayed filing of a return reporting that period’s supplies, interest generally concerns GST payable through the cash ledger, subject to applicable conditions.
If ₹30,000 attracts interest for 10 days, the calculation is:
₹30,000 × 18% × 10 ÷ 365 = approximately ₹148.
This assumes no qualifying cash balance reduces the interest amount. Money deposited by the due date and remaining available until used for payment can qualify for exclusion. Check the balance and payment dates rather than calculating interest on the entire GST amount.
Example: a March invoice is reported in September
Assume a monthly taxpayer missed a March 2026 invoice carrying ₹18,000 GST and did not pay that GST earlier. The invoice is added in September GSTR-1, and the ₹18,000 is paid entirely in cash through September GSTR-3B on 20 October 2026.
Assuming the March payment deadline was 20 April 2026, with no extension or other relief, the delay is 183 days.
₹18,000 × 18% × 183 ÷ 365 = ₹1,624.44 interest.
Identify this amount as March liability in the period-wise breakup when filing September GSTR-3B. Interest is calculated up to the date the GST is paid. Reporting the invoice late does not create interest if its GST was already paid on time.
Review and pay the applicable interest through Table 5.1. The portal's automatic calculation may show it in the following period's GSTR-3B; account for any interest already paid to avoid paying twice. Interest is payable in cash.
Delayed QRMP monthly payments also require an interest calculation based on the applicable payment method and deadline.
What if you discover a mistake after filing?
A filed GSTR-3B cannot be revised. For an omitted supply, examine the amendment route and related GST payment. For excess credit, review reversal or repayment and applicable interest. For missed eligible credit, check the remaining claim deadline.
Ordinary corrections generally close on 30 November following the financial year or filing of the relevant annual return, whichever is earlier, subject to applicable conditions.
Record the correction and avoid paying amounts already settled.
Can a mismatch lead to a GST notice?
If GST reported in GSTR-1/IFF is higher than GST reported in GSTR-3B beyond the portal’s prescribed limits, you may receive a mismatch intimation in Form DRC-01B. It asks you to pay any actual shortfall with applicable interest, explain the difference, or do both. A mismatch does not automatically mean more GST is payable; reconcile the figures and submit the response within the stated deadline.
Final filing checklist
Before filing, confirm:
- Correct GSTIN and period selected.
- GSTR-1 filed and relevant GSTR-1A changes included.
- Supplies and purchase credit matched with records.
- Reversals, reclaims and reverse-charge GST reviewed.
- Notes, advances and earlier-period adjustments included.
- Draft summary matched with the working sheet.
- Credit use, cash payment, interest and late fees checked.
After filing, verify Filed status and retain the acknowledgement.
Our GST return filing services in Chennai can assist.