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.
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.
Monthly filers pay by the 20th. QRMP filers pay monthly but file quarterly.
| Feature | 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 |
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.
Follow these steps for accurate monthly filing
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.
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.
Errors that trigger interest, penalties, and GST notices
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.
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.
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.
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.
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.
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.
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.
myBillPlease auto-calculates output tax, input credit, and net payable. Download the report and file. Free plan available.
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