GSTR-3B: Format, Due Dates, Filing Steps & Latest Updates

Key GSTR-3B Changes in 2025-2026

Critical Update: Major System Changes Effective in 2025-2026

The GST portal has implemented significant changes to GSTR-3B mechanics. If you are filing under old assumptions, you may face system errors, mismatch issues, or compliance gaps.

What These Changes Mean for Your Filing Workflow

Before July 2025, taxpayers could manually enter outward supply figures in GSTR-3B Table 3, which made mismatch with GSTR-1 possible.

From the updated system rollout, outward liability figures in the relevant Table 3 fields are driven from GSTR-1, GSTR-1A, and IFF. That means the filing order matters even more now.

What you must do now:

• File GSTR-1 first
• Review outward liability figures auto-populated in GSTR-3B
• If GSTR-1 data is wrong, correct it through GSTR-1A within the same period where available, before filing GSTR-3B
• Complete ITC, reversals, and payment sections carefully
• Check reclaim ledger balance before reporting reclaimed ITC in Table 4(D)(1)

Who Needs to File GSTR-3B?

All regular GST-registered taxpayers must file GSTR-3B, including:

• Companies, firms, LLPs, and individuals registered under GST with taxable outward supplies
• Exporters of goods or services
• Businesses under the QRMP scheme , which file quarterly but pay monthly through challan
• Businesses with nil activity for the period, which must still file nil GSTR-3B

Who does not file GSTR-3B?

• Composition scheme taxpayers, who file GSTR-4 instead
• Non-resident taxable persons, who file GSTR-5
• Input Service Distributors, who file GSTR-6
• TDS deductors, who file GSTR-7

TCS collectors such as certain e-commerce operators, who file GSTR-8

GSTR-3B Due Dates: Monthly and QRMP

Monthly Filers

QRMP Filers

Monthly tax payment for QRMP: Even though GSTR-3B is quarterly, QRMP filers must deposit tax monthly through challan by the 25th of the following month for months 1 and 2 of each quarter.

State-wise QRMP Due Date Groups (22nd vs 24th)

Under QRMP, quarterly GSTR-3B due dates differ by state and Union Territory:

GSTR-3B Format: Table-by-Table Breakdown

Understanding what goes into each table is essential for accurate filing, especially after the recent auto-population changes.

Table 3: Outward Supplies and Reverse Charge

Table 3.1 - Details of Outward Supplies

From the updated system rollout, relevant liability values in Table 3.1 are auto-filled from your filed GSTR-1, GSTR-1A, or IFF. These fields are read-only. Review them for accuracy before submitting GSTR-3B.

Table 3.2 - Inter-state Supplies to Specific Recipients

This table reports inter-state supplies made to:

Unregistered persons

Composition taxable persons

UIN holders

From November 2025, these values are auto-populated from GSTR-1 / IFF and cannot be changed manually.

Table 4: Input Tax Credit (ITC)

Table 4 is the most complex section and remains critical for filing accuracy. It captures ITC available, reversed, net claimed, and reclaimed.

Table 5 (Exempt/Non-GST Inward Supplies)
Captures summary of purchases from composition dealers and other non-taxable inward supplies.

Table 5.1 (Interest & Late Fee): 

• Effective January 2026, interest is auto-calculated based on your net cash shortfall.

• The portal-computed interest is non-editable downward; you can only increase the amount if your own calculations are higher.

Table 6: Tax Payable and Paid

Table 6.1 is the payment reconciliation table. It shows exactly how much liability you are settling through the electronic credit ledger and how much through the electronic cash ledger.

How GSTR-1, GSTR-2B, and GSTR-3B Work Together

These three returns form an interconnected system:

GSTR-1 (your outward supply reporting) -> GSTR-2B (recipient's ITC visibility) -> GSTR-3B (your tax payment and your own ITC claim)

The workflow is:

• You file GSTR-1 with invoice-level details of outward supplies
• Those invoices flow into the recipient's GSTR-2B
• The recipient uses GSTR-2B as the practical basis for ITC reconciliation before filing GSTR-3B
• At the same time, your own GSTR-1 data auto-populates outward liability fields in your GSTR-3B
• You then complete Table 4, calculate net liability in Table 6, pay tax, and file

The critical link is simple: your GSTR-1 filing affects both your own GSTR-3B liability flow and your buyer's ITC visibility.

How to File GSTR-3B on the GST Portal (Step-by-Step)

1. Log in to the GST Portal with your credentials.

2. Go to Services > Returns > Returns Dashboard and select the relevant Financial Year and Tax Period.

3. Click Prepare Online under the GSTR-3B tile.

4. Review Auto-Populated Data (Table 3):

1. Mandatory Sequence: You must file GSTR-1 for the same period before GSTR-3B can be filed.
2. Outward liability in Table 3.1 and Table 3.2 is auto-populated from GSTR-1, GSTR-1A, or IFF.

c. Non-Editable Rule: Since July 2025, these fields are hard-locked. If values are incorrect, you must file Form GSTR-1A to amend them before proceeding with GSTR-3B.

5. Complete ITC & Other Details (Tables 4 & 5):

d. Table 4 (Eligible ITC): Auto-populated from GSTR-2B. Verify and apply reversals as needed.

e. Table 5: Manually enter exempt, nil-rated, and non-GST inward supplies.

6. Save & Compute Liability:

f. Click Save GSTR-3B.

g. Click Proceed to Payment. The system computes the net tax payable after automatically offsetting available ITC.

7. NEW MANDATORY STEP: Tax Liability Breakup:

h. As of February 2026, if you are discharging any liability for a previous period in the current return, you must click the Tax Liability Breakup, As Applicable button.

i. Provide the period-wise breakup and click Save within this tab. Failure to do this may keep the "Proceed to File" button disabled.

8. Payment & Offset:

j. If the cash ledger balance is insufficient, click Create Challan to pay via net banking, UPI, or NEFT/RTGS.

k. Click Make Payment/Post Credit to Ledger to finalize the offset. Once clicked, data is locked and cannot be edited.

9. Preview & Filing:

i. Click Preview Draft GSTR-3B to review the final PDF.

m. Select the declaration checkbox and authorized signatory.

n. Click File GSTR-3B with EVC (OTP-based) or DSC (Digital Signature).

o. Download the ARN acknowledgement for your records. 

Late Fee, Interest, and Penalty for GSTR-3B

Daily Late Fee Rates

Turnover-Based Maximum Late Fee Caps

Interest on Delayed Tax Payment

• Rate: 18% per annum on unpaid tax
• Calculation: Daily interest from the GSTR-3B due date to the actual payment date
• Formula: Outstanding tax x 18% x (Days delayed ÷ 365)

Example:
Rs 1,00,000 tax delayed by 30 days
= Rs 1,00,000 x 18% x 30 / 365
= about Rs 1,479 interest

Late fee and interest are separate. Both can apply when filing is delayed and tax remains unpaid.

GSTR-3B Nil Return: When and How to File

If your business had no outward supplies, no ITC to claim , and no tax to pay in a period, you must still file a Nil GSTR-3B .

Filing nil is not optional. Non-filing still attracts late fee, though at the lower nil-return rate.

Who Must File Nil GSTR-3B

• Businesses with zero sales in the period
• Seasonal businesses with no activity in off-season months
• Newly registered businesses that have not started trading
• Registered businesses with no reportable activity for the period

How to File Nil GSTR-3B

• Log in to the GST portal
• Open Returns Dashboard and select GSTR-3B
• Ensure all fields show zero
• Click Confirm Nil Return
• Verify and submit
• File with EVC

Late fee for nil returns applies at the lower daily rate and is subject to the applicable cap.

ITC in GSTR-3B: Table 4 Explained

Table 4 is where ITC is claimed in GSTR-3B. System validations have tightened, especially for reclaimed ITC.

The Golden Rule of ITC in GSTR-3B

As a practical and legally safer compliance rule, claim ITC only after:

• It is visible through GSTR-2B based reconciliation
• The other Section 16 conditions are satisfied
• It is not blocked, reversed, or otherwise ineligible

ITC Auto-Population and Review

System data flows into Table 4, but the taxpayer still has to:

• Review whether the credit is actually eligible
• Exclude blocked or ineligible credit
• Report reversals correctly
• Ensure reclaim entries are within the available reclaim balance

The system calculates Net ITC in Table 4(C) after considering reversals.

Rule 42 and 43: ITC Reversal in GSTR-3B

If your business uses inputs, input services, or capital goods partly for taxable supplies and partly for exempt or non-business purposes, you cannot claim full ITC.

You must reverse proportionate credit under:

• Rule 42 for inputs and input services
• Rule 43 for capital goods

How to Report in GSTR-3B

Rule 42 / 43 reversals are reported in Table 4(B)(1), the non-reclaimable ITC reversal row.

Example:
A real estate developer uses common inputs for both taxable and exempt portions. If total GST on common input is Rs 1,80,000 and 40% relates to exempt use, reversal = Rs 72,000. That amount is reported in Table 4(B)(1).

A commonly missed point is that even businesses selling only taxable goods may still need reversal if common inputs relate partly to exempt income streams such as exempt interest income.

Rule 86A: ITC Blocking Risk

Rule 86A empowers the department to block use of ITC in the electronic credit ledger where there is reason to believe the credit is fraudulently availed or otherwise ineligible.

What Blocking Means

When ITC is blocked:

• You cannot use that blocked ITC to pay output tax
• You may have to pay from cash instead
• The block can continue up to the permitted duration under the rule

How to Reduce Rule 86A Risk

• File GSTR-3B on time
• Reconcile GSTR-2B before claiming ITC
• Avoid claiming ITC from suspicious or non-compliant suppliers
• Respond promptly to departmental communications
• Maintain proper purchase records and invoice trail

Negative ITC: What to Do When ITC Exceeds Liability

If your ITC is higher than your output tax liability in a period, you will have excess ITC.

What Happens to Excess ITC

• It is not lost
• It carries forward automatically in the electronic credit ledger
• It can be used against future output liability
• In eligible cases such as exports, refund provisions may apply

How to Handle in Table 6

If ITC exceeds liability:

• Use ITC only up to the amount of liability
• Net cash liability becomes zero if sufficient ITC exists
• Remaining ITC carries forward automatically
• Do not enter negative values in the tax payment table

Also make sure reclaimed ITC entries do not exceed the system-allowed reclaim balance.

Real-World Example: Priya's Textile Business

Scenario: Priya's Textiles is a B2B fabric manufacturer in Maharashtra, a monthly GSTR-3B filer with Rs 8 crore annual turnover.

April 2026 transactions

Step 1: GSTR-1 filed by May 11

Both sales invoices are reported correctly in GSTR-1.

Step 2: GSTR-3B Table 3 auto-populated

Table 3.1(a) and related outward liability fields reflect outward taxable value of Rs 8,00,000 and corresponding tax of:

• CGST Rs 30,000
• SGST Rs 30,000
• IGST Rs 36,000

Priya reviews and confirms the figures.

Step 3: GSTR-2B reconciled and Table 4 completed

ITC available after reconciliation:

• CGST Rs 21,000
• SGST Rs 21,000

No reversals are required because all inputs are used for taxable supplies.

Step 4: Table 6 - Net Liability and Payment

Priya pays Rs 54,000 via challan and files GSTR-3B by May 20.

Downstream result: ABC Garments and Delhi Exporters can reconcile Priya's invoices in their relevant GSTR-2B and take eligible ITC subject to their own compliance checks and the applicable statutory conditions.

How to Correct GSTR-3B Errors

GSTR-3B cannot be revised once filed. Corrections are made in later periods or through the proper permitted mechanism.

If You Underpaid Tax

• Calculate the shortfall head-wise
• Pay differential tax with interest
• Reflect the correction through the appropriate later-period route
• Keep working papers showing reason and calculation

If You Overpaid Tax

• Track the excess in your books
• Adjust it against future liability where permitted
• Use refund route where applicable and eligible

If You Wrongly Claimed or Missed ITC

• Excess ITC claimed: reverse it in the later return and pay resulting liability with interest if required

Missed ITC: claim it in the next eligible period after proper GSTR-2B reconciliation and subject to the applicable time limit

For a detailed side-by-side breakdown, see our complete GSTR-1 vs GSTR-3B comparison guide.

For a detailed side-by-side breakdown, see our complete GSTR-1 vs GSTR-3B comparison guide.

3-Year Filing Limit: The Time Bar Rule

A portal-based 3-year filing time bar now applies to delayed GSTR-3B filings.

Practical implications

• If a GSTR-3B period crosses the portal-enforced 3-year filing limit from its due date, filing may no longer be possible
• Returns left unfiled beyond that limit can remain as serious compliance defaults
• Businesses should not keep old periods pending on the assumption that they can be filed at any time in the future

Action required

If you have very old unfiled GSTR-3B returns, clear them immediately. Even if late fee and interest apply, a filed return is far better than risking permanent non-filing status for that period.

Pre-Filing Checklist

Run this checklist before every GSTR-3B filing.

Before Filing GSTR-1 or completing outward source data

• All sales invoices for the period are entered in the accounting system
• Credit notes and debit notes are correctly recorded
• IGST vs CGST + SGST classification is verified per place of supply
•  Outward reporting is completed within the due date
• Any same-period correction requirement is identified early

Before Filing GSTR-3B

•  GSTR-2B downloaded and reconciled against purchase register
•  ITC claimed only after GSTR-2B reconciliation and applicable Section 16 checks
•  Table 3 outward liability figures reviewed against books
• Table 3.2 inter-state supply data checked
•  Rule 42 / 43 reversal calculated if mixed-use inputs exist
•  Reclaim ledger balance checked before entering Table 4(D)(1)
•  Net liability computed and challan payment made
•  Tax payment reflected in electronic cash ledger before filing
• Draft GSTR-3B PDF downloaded and reviewed
• Any pending DRC-01B or older mismatch issue has been addressed

Conclusion

GSTR-3B is more than a compliance checkbox. It is the return through which your GST position for the period is actually settled.

The most important things to know now are:

• outward liability reporting in GSTR-3B is now tightly linked to GSTR-1 / GSTR-1A / IFF
• ITC still needs proper GSTR-2B reconciliation and Section 16 condition checks
• nil returns must still be filed where applicable
• late fee and interest both matter
• old return periods should not be left pending because portal-based filing limits now matter much more

BUSY accounting software helps manage this process by generating GSTR-3B from a single set of books, reducing manual effort and lowering the risk of mismatch, omission, and rework. Businesses that want to manage return filing, ITC, and books in one place can use GST accounting software that connects outward reporting directly to payment and compliance tracking.