What is the due date for GSTR-3B filing?

For monthly filers (businesses with turnover above Rs 5 crore), GSTR-3B is due by the 20th of the following month. For example, March 2026 GSTR-3B is due by April 20, 2026. For quarterly filers under the QRMP scheme (turnover up to Rs 5 crore), GSTR-3B is filed quarterly but tax must be paid monthly by the 25th using form PMT-06. The quarterly GSTR-3B due date varies by state — typically the 22nd to 24th of the month following the quarter. Late filing attracts Rs 50 per day up to Rs 10,000. Late payment attracts 18% annual interest.

What is the difference between GSTR-1 and GSTR-3B?

GSTR-1 is a detailed return of all your outward supplies — every invoice, credit note, and debit note reported individually with customer details, HSN codes, and tax breakdowns. It tells the government what you sold. GSTR-3B is a summary return where you declare your total output tax, claim input tax credit, and pay the net tax. It tells the government how much you are paying. Both must be filed — GSTR-1 by the 11th and GSTR-3B by the 20th of the following month. Your GSTR-1 data feeds into your customer's GSTR-2B which they use for ITC claims.

Can I revise GSTR-3B after filing?

No, GSTR-3B cannot be revised after filing. This is a critical difference from income tax returns which allow revisions. Once you click File on GSTR-3B, the return is final. If you discover errors after filing — wrong output tax, wrong ITC, or wrong payment — you must correct them in the next month's GSTR-3B. Underpayment in one month is compensated by additional payment in the next. Overpayment creates excess in your electronic credit ledger which adjusts in subsequent months. This is why reviewing your GSTR-3B thoroughly before filing is so important.

How do I calculate net tax payable in GSTR-3B?

The calculation is straightforward. Total output tax liability is the sum of CGST, SGST, and IGST collected on all your sales invoices during the month (Table 3.1). Input tax credit is the ITC available from your purchases as shown in GSTR-2B and verified against your purchase records (Table 4). Net tax payable equals output tax minus input tax credit. If output tax is Rs 50,000 and ITC is Rs 35,000, you pay Rs 15,000. If ITC exceeds output tax, the excess carries forward. IGST credit can be used against CGST and SGST liability, but CGST credit cannot be used for SGST and vice versa.

What happens if I file GSTR-3B late?

Late filing of GSTR-3B attracts two consequences. First, a late fee of Rs 50 per day of delay — Rs 25 CGST and Rs 25 SGST — capped at Rs 10,000 per return. For nil returns, the late fee is Rs 20 per day capped at Rs 500. Second, interest at 18% per annum on the unpaid tax amount from the due date to the date of actual payment. If you owed Rs 1 lakh and paid 30 days late, the interest is approximately Rs 1,479. Additionally, consistent late filing can result in your GST registration being suspended. Always file by the 20th and pay tax before the due date.

What is the QRMP scheme for GSTR-3B?

QRMP stands for Quarterly Return Monthly Payment. It allows businesses with turnover up to Rs 5 crore to file GSTR-1 and GSTR-3B quarterly instead of monthly. However, tax must still be paid every month by the 25th using form PMT-06. The monthly tax payment can be calculated using either the fixed sum method (based on the previous quarter's liability) or the self-assessment method (based on actual liability for the month). The quarterly GSTR-3B is then filed after the quarter ends, adjusting for the monthly payments already made. This scheme reduces filing frequency from 24 returns to 8 per year.

How does myBillPlease help with GSTR-3B filing?

myBillPlease auto-generates your GSTR-3B report from your sales and purchase data. Output tax is calculated from all invoices created during the month with automatic CGST, SGST, and IGST splits. Input tax credit is calculated from recorded purchase invoices. The report covers all GSTR-3B tables — outward supplies in Table 3.1, ITC in Table 4, exempt supplies in Table 5, and the final tax payable summary. Download as Excel, compare with the GST portal auto-populated data, and file. The Starter plan adds GSTR-2B reconciliation to verify ITC claims before filing. No manual calculations, no Excel formulas, no tax head confusion.

GST Returns & Filing

How to File GSTR-3B in 2026: Step by Step Guide with Due Dates

GSTR-3B is your monthly summary return for GST. It determines how much tax you actually pay. Here is the complete filing process, due dates, and how to calculate your net liability.

Himanshu23 March 2026 · 5 min read · updated 6 September 2026

A mid-adult calculating finances with a laptop and notepad, managing budgets at home.

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Key takeaways

GSTR-3B is the self-assessed summary where you declare output tax, claim ITC in Table 4 and pay the net in Table 6.
Monthly filers file by the 20th; QRMP filers pay monthly via PMT-06 by the 25th and file quarterly by the 22nd or 24th.
Late filing costs Rs 50 per day up to Rs 10,000 plus 18% interest on unpaid tax; a filed GSTR-3B cannot be revised.
Claim only ITC visible in GSTR-2B, reverse Section 17(5) blocked credits, and report RCM liability in Table 3.1(d).

What is GSTR-3B and Why Does It Matter?

GSTR-3B is a monthly self-assessed summary return that every GST-registered business in India must file. While GSTR-1 reports your outward supplies (sales), GSTR-3B is where you actually calculate and pay your GST liability. It summarises your total output tax, claims input tax credit, and arrives at the net tax you owe the government.

Think of it this way: GSTR-1 tells the government what you sold. GSTR-3B tells the government how much tax you are paying after deducting your input credits. The actual money transfer happens through GSTR-3B.

Filing GSTR-3B correctly is critical because underpayment attracts interest at 18% per annum, and late filing attracts a penalty of Rs 50 per day (Rs 20 for nil returns). We designed myBillPlease to auto-generate your GSTR-3B from your sales invoices and purchase records — so the numbers are always accurate and filing takes minutes instead of hours.

This guide walks through every table in GSTR-3B, the step-by-step filing process, due dates for 2026, and common mistakes to avoid. Use our GST calculator to verify any tax calculations before filing.

GSTR-3B Due Dates 2026

Monthly filers pay by the 20th. QRMP filers pay monthly but file quarterly.

	Monthly Filing	QRMP Scheme
Who qualifies	Turnover > Rs 5 crore	Turnover ≤ Rs 5 crore (optional)
Filing frequency	Every month	Quarterly (but pay tax monthly via PMT-06)
January 2026	Due: Feb 20	Tax by Feb 25 via PMT-06
February 2026	Due: Mar 20	Tax by Mar 25 via PMT-06
March 2026 (Q4)	Due: Apr 20	GSTR-3B due: Apr 22-24*
April 2026	Due: May 20	Tax by May 25 via PMT-06
May 2026	Due: Jun 20	Tax by Jun 25 via PMT-06
June 2026 (Q1)	Due: Jul 20	GSTR-3B due: Jul 22-24*
Late fee	Rs 50/day (max Rs 10,000)	Rs 50/day (max Rs 10,000)
Interest on late payment	18% p.a. on tax amount	18% p.a. on tax amount

Understanding GSTR-3B Tables

GSTR-3B has 6 main tables. Understanding what goes where is the key to accurate filing:

Table 3.1 — Outward Supplies: Your total sales broken into taxable supplies (both inter-state and intra-state), zero-rated supplies (exports), nil-rated and exempt supplies, and non-GST supplies. The taxable supply values come from your sales invoices. If you use myBillPlease, this is auto-calculated from your invoicing data.

Table 3.2 — Inter-State Supplies to Unregistered Persons: If you made inter-state sales to customers without GSTIN (B2C) and the invoice value exceeds Rs 2.5 lakh, they are reported here state-wise.

Table 4 — Eligible ITC: This is where you claim your input tax credit. It shows ITC available from GSTR-2B, ITC reversed (for blocked credits or rule violations), and net ITC available. The net ITC reduces your output tax liability.

Table 5 — Exempt, Nil-Rated, and Non-GST Inward Supplies: Purchases of exempt or nil-rated goods. This table is informational — it does not affect your tax calculation but must be filled accurately.

Table 6 — Payment of Tax: The final table where you see your total liability (output tax minus ITC), pay using electronic cash or credit ledger, and any excess that carries forward. This is where the actual payment happens.

The calculation is straightforward: Tax Payable = Output Tax (Table 3.1) - Input Tax Credit (Table 4) = Net Payment (Table 6). If ITC exceeds output tax, the balance carries forward to the next month.

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

Follow these steps for accurate monthly filing

Step 1: Log in to gst.gov.in → Returns Dashboard → Select the filing month
Step 2: Click GSTR-3B tile → The form auto-populates from your GSTR-1 and GSTR-2B data
Step 3: Review Table 3.1 — verify outward supply values match your sales register
Step 4: Review Table 4 — verify ITC amounts match your GSTR-2B and purchase register
Step 5: Check for ITC reversals — blocked credits, rule 42/43 reversals, and time-barred ITC
Step 6: Review Table 5 — add exempt and non-GST purchase values
Step 7: Preview Table 6 — verify the net tax payable looks correct
Step 8: Create challan and pay the tax via net banking, NEFT, or RTGS
Step 9: After payment reflects in cash ledger, go back to GSTR-3B and click Submit
Step 10: File with DSC or EVC — GSTR-3B is now filed and cannot be revised

Filing Nil GSTR-3B

If you had no sales, no purchases, and no tax liability for the month, you still must file GSTR-3B. Filing a nil return is simple — log in to the portal, go to GSTR-3B, verify all tables show zero, and file with EVC. The process takes under 2 minutes.

Skipping a nil return has consequences

Not filing a nil return attracts a late fee of Rs 20 per day up to Rs 500 (Rs 10 CGST + Rs 10 SGST per day). More importantly, consecutive non-filing can lead to your GST registration being suspended by the tax officer under Section 29(2).

Common nil return scenario: Seasonal businesses that operate only during certain months. A festival stall operator registered for GST might have sales only in October-December. For the other 9 months, nil GSTR-3B returns must be filed every month.

Common GSTR-3B Filing Mistakes

ITC Overclaim

Claiming more ITC than what appears in GSTR-2B. The system flags this automatically. Stick to GSTR-2B amounts and resolve mismatches with suppliers before claiming additional credit.

Wrong Tax Period

Reporting invoices in the wrong month. A March sale reported in April GSTR-3B creates a mismatch with GSTR-1. Always report in the period the invoice was issued.

Not Reversing Blocked ITC

Claiming ITC on items listed under Section 17(5) — motor vehicles, food, personal use items. These must be reversed in Table 4. Not reversing triggers a demand notice.

IGST vs CGST+SGST Error

Reporting inter-state supply as intra-state or vice versa. This changes the tax head — IGST goes to central, CGST+SGST splits between central and state. Wrong classification complicates refunds.

Late Payment Interest

Filing on time but paying tax late. Interest at 18% p.a. accrues from the due date to the payment date — even if you file the return on time. Pay before the 20th.

Forgetting RCM Liability

Reverse charge mechanism purchases (like legal services, transport by GTA) create additional output tax liability. Not reporting RCM in Table 3.1(d) means underpayment.

Auto-Generate Your GSTR-3B — Stop Manual Calculations

The most error-prone part of GSTR-3B is calculating the numbers that go into each table. Output tax from dozens or hundreds of invoices, ITC from purchase records, inter-state vs intra-state splits, RCM adjustments — doing this manually in Excel is a recipe for mistakes.

myBillPlease generates your GSTR-3B report automatically from your billing data. Every sales invoice you create feeds into the output tax calculation. Every purchase invoice you record feeds into the ITC calculation. The system handles CGST/SGST/IGST splits based on state codes in your invoices.

At month-end, go to Reports → GSTR-3B → Download. The Excel file has every table pre-filled. Compare it against the auto-populated data on the GST portal, verify they match, and file. The entire process takes 10 minutes instead of 2 hours.

The free plan includes basic GSTR-3B generation. The Starter plan at Rs 799/month adds GSTR-2B reconciliation so your ITC claims are verified before filing. See pricing for all plan details.

Frequently asked questions

What is the due date for GSTR-3B filing?: For monthly filers (businesses with turnover above Rs 5 crore), GSTR-3B is due by the 20th of the following month. For example, March 2026 GSTR-3B is due by April 20, 2026. For quarterly filers under the QRMP scheme (turnover up to Rs 5 crore), GSTR-3B is filed quarterly but tax must be paid monthly by the 25th using form PMT-06. The quarterly GSTR-3B due date varies by state — typically the 22nd to 24th of the month following the quarter. Late filing attracts Rs 50 per day up to Rs 10,000. Late payment attracts 18% annual interest.
What is the difference between GSTR-1 and GSTR-3B?: GSTR-1 is a detailed return of all your outward supplies — every invoice, credit note, and debit note reported individually with customer details, HSN codes, and tax breakdowns. It tells the government what you sold. GSTR-3B is a summary return where you declare your total output tax, claim input tax credit, and pay the net tax. It tells the government how much you are paying. Both must be filed — GSTR-1 by the 11th and GSTR-3B by the 20th of the following month. Your GSTR-1 data feeds into your customer's GSTR-2B which they use for ITC claims.
Can I revise GSTR-3B after filing?: No, GSTR-3B cannot be revised after filing. This is a critical difference from income tax returns which allow revisions. Once you click File on GSTR-3B, the return is final. If you discover errors after filing — wrong output tax, wrong ITC, or wrong payment — you must correct them in the next month's GSTR-3B. Underpayment in one month is compensated by additional payment in the next. Overpayment creates excess in your electronic credit ledger which adjusts in subsequent months. This is why reviewing your GSTR-3B thoroughly before filing is so important.
How do I calculate net tax payable in GSTR-3B?: The calculation is straightforward. Total output tax liability is the sum of CGST, SGST, and IGST collected on all your sales invoices during the month (Table 3.1). Input tax credit is the ITC available from your purchases as shown in GSTR-2B and verified against your purchase records (Table 4). Net tax payable equals output tax minus input tax credit. If output tax is Rs 50,000 and ITC is Rs 35,000, you pay Rs 15,000. If ITC exceeds output tax, the excess carries forward. IGST credit can be used against CGST and SGST liability, but CGST credit cannot be used for SGST and vice versa.
What happens if I file GSTR-3B late?: Late filing of GSTR-3B attracts two consequences. First, a late fee of Rs 50 per day of delay — Rs 25 CGST and Rs 25 SGST — capped at Rs 10,000 per return. For nil returns, the late fee is Rs 20 per day capped at Rs 500. Second, interest at 18% per annum on the unpaid tax amount from the due date to the date of actual payment. If you owed Rs 1 lakh and paid 30 days late, the interest is approximately Rs 1,479. Additionally, consistent late filing can result in your GST registration being suspended. Always file by the 20th and pay tax before the due date.
What is the QRMP scheme for GSTR-3B?: QRMP stands for Quarterly Return Monthly Payment. It allows businesses with turnover up to Rs 5 crore to file GSTR-1 and GSTR-3B quarterly instead of monthly. However, tax must still be paid every month by the 25th using form PMT-06. The monthly tax payment can be calculated using either the fixed sum method (based on the previous quarter's liability) or the self-assessment method (based on actual liability for the month). The quarterly GSTR-3B is then filed after the quarter ends, adjusting for the monthly payments already made. This scheme reduces filing frequency from 24 returns to 8 per year.
How does myBillPlease help with GSTR-3B filing?: myBillPlease auto-generates your GSTR-3B report from your sales and purchase data. Output tax is calculated from all invoices created during the month with automatic CGST, SGST, and IGST splits. Input tax credit is calculated from recorded purchase invoices. The report covers all GSTR-3B tables — outward supplies in Table 3.1, ITC in Table 4, exempt supplies in Table 5, and the final tax payable summary. Download as Excel, compare with the GST portal auto-populated data, and file. The Starter plan adds GSTR-2B reconciliation to verify ITC claims before filing. No manual calculations, no Excel formulas, no tax head confusion.