How to File GSTR-3B Step by Step — GST Return Filing Guide for Small Business 2026
GSTR-3B is the most important monthly GST return for businesses in India. This step-by-step guide explains what GSTR-3B is, when to file, what figures go in each section, and how to file it on the GST portal without making costly mistakes.
GSTR-3B is the monthly (or quarterly) self-assessed GST return that every regular GST taxpayer must file. It is not based on invoice-by-invoice data — it is a summary return where you report your total outward supplies, eligible Input Tax Credit, and the net GST payable for the period. Filing GSTR-3B on time is critical: the late fee is ₹50 per day (or ₹20 per day for nil returns), capped at ₹10,000, plus 18% interest on any unpaid tax.
This guide walks you through exactly what GSTR-3B is, how to calculate the figures for each table, and a step-by-step process to file it on the GST portal.
What is GSTR-3B?
GSTR-3B is a monthly summary return under the GST system. Unlike GSTR-1 (which requires invoice-level details of all outward supplies), GSTR-3B requires only consolidated figures. However, the numbers you enter in GSTR-3B must match the figures in your GSTR-1. GSTR-3B is used to:
- Declare the total value of outward taxable supplies (sales) for the month
- Report ITC (Input Tax Credit) received on purchases and expenses
- Calculate net GST payable after adjusting ITC
- Pay the net GST liability into the electronic cash ledger
- File the return by the due date to avoid late fees and interest
GSTR-3B Due Dates 2026
| Taxpayer Category | Filing Frequency | Due Date |
|---|---|---|
| Turnover > ₹5 crore (monthly filers) | Monthly | 20th of the following month |
| QRMP — Category 1 states (UP, Maharashtra, etc.) | Quarterly | 22nd of month after quarter end |
| QRMP — Category 2 states (Gujarat, Rajasthan, etc.) | Quarterly | 24th of month after quarter end |
| Nil return filers (no transactions) | Monthly or Quarterly | Same as above — late fee still applies |
QRMP Scheme
Small taxpayers with annual turnover up to ₹5 crore can opt for the QRMP (Quarterly Return Monthly Payment) scheme. You file GSTR-3B quarterly but pay tax monthly using PMT-06 challan (by the 25th of each month). This reduces your return filing burden from 12 to 4 times a year.
GSTR-3B Tables: What Goes Where
GSTR-3B has 6 main tables. Here is what each one requires:
| Table | Name | What to Fill |
|---|---|---|
| 3.1 | Outward Supplies (Sales) | Total taxable value of sales, broken by tax rate (5%, 12%, 18%, 28%). Also show CGST, SGST, IGST amounts. |
| 3.1.1 | Inward Supplies on reverse charge | Purchases on which you pay GST under reverse charge (e.g., services from unregistered vendors above threshold) |
| 3.2 | Inter-state supplies to unregistered persons | IGST on B2C inter-state sales (for interstate B2C supplies to individuals, state-wise breakdown if applicable) |
| 4 | ITC Available | Total eligible ITC from GSTR-2B — split by IGST, CGST, SGST. Further split by inputs, input services, capital goods. |
| 5 | ITC Reversed / Ineligible | ITC you cannot claim — personal use, blocked credits (Section 17(5)), reversals |
| 6 | Tax Payable and Paid | Net GST payable = Output tax – Eligible ITC. Show payment from ITC ledger and cash ledger. |
Step-by-Step: How to File GSTR-3B on GST Portal
- 1Log in to gst.gov.in using your GSTIN and password
- 2Go to Services → Returns → Returns Dashboard
- 3Select the Financial Year and Return Filing Period (month/quarter)
- 4Click on 'GSTR-3B' and then 'Prepare Online'
- 5Table 3.1 — Enter your total outward taxable supplies. Break them by tax rate. The system auto-populates from your GSTR-1 if you have filed it. Verify the figures match your sales records.
- 6Table 4 — Enter your ITC. GSTR-2B (auto-generated from your suppliers' GSTR-1) shows the ITC available to you. Enter figures from GSTR-2B — do not claim more than what is in GSTR-2B.
- 7Table 5 — Enter any ITC reversals if applicable (ineligible credits, personal use portion, etc.)
- 8Table 6 — Review the net tax payable calculated by the system. If ITC is insufficient, you must pay the balance via challan (online payment through net banking or UPI).
- 9Click 'Preview Draft GSTR-3B' to review the full return before filing
- 10Click 'File GSTR-3B' and sign using DSC (Digital Signature Certificate) or EVC (OTP on registered mobile)
- 11Save the ARN (Acknowledgement Reference Number) as proof of filing
How ITC Works in GSTR-3B
Input Tax Credit (ITC) is the heart of GSTR-3B. It allows you to set off the GST you paid on business purchases against the GST you collected on sales. To claim ITC correctly:
- Download your GSTR-2B from the GST portal — it shows all ITC available based on what your suppliers have uploaded in their GSTR-1
- You can only claim ITC that appears in GSTR-2B (as of Rule 36(4) — maximum 105% of GSTR-2B ITC)
- ITC is not available on: personal expenses, motor vehicles (for most businesses), food and beverages, club memberships, construction of immovable property
- If your supplier has not filed their GSTR-1, their invoices will not appear in your GSTR-2B — follow up with them to avoid ITC denial
Common Mistakes When Filing GSTR-3B
- Mismatch between GSTR-1 and GSTR-3B figures — GST system flags these discrepancies automatically
- Claiming ITC more than what is in GSTR-2B — attracts demand notices
- Not reporting reverse charge purchases (Table 3.1.1) — RCM liability is separate from output tax
- Forgetting nil return — even if there are no transactions, filing NIL GSTR-3B is mandatory to avoid the ₹20/day late fee
- Paying tax in wrong head — IGST, CGST, and SGST cannot be cross-utilized freely. IGST can be set off against all, but CGST and SGST can only be used for their respective heads
- Not reconciling with books before filing — always match with your Tally, Excel, or accounting software before submitting
GSTR-3B vs GSTR-1: What is the Difference?
| Feature | GSTR-1 | GSTR-3B |
|---|---|---|
| Purpose | Report invoice-wise outward supplies | Self-assessed summary return + tax payment |
| Data level | Invoice-level (B2B, B2C, export, etc.) | Summary (consolidated figures) |
| Due date | 11th of next month (monthly) | 20th of next month (monthly) |
| ITC claim | No | Yes — ITC declared in Table 4 |
| Tax payment | No | Yes — net tax paid here |
| Can be amended? | Yes — up to annual return | Cannot be amended after filing (only GSTR-1 can correct outward supplies) |
File GSTR-1 first
Always file GSTR-1 before GSTR-3B for the same period. The data in GSTR-1 flows to your customers' GSTR-2B (enabling their ITC claims). Filing GSTR-3B first without GSTR-1 creates a mismatch that the system flags.
How to Avoid Late Fee on GSTR-3B
- Set a reminder for the 20th of every month (or 22nd/24th for quarterly QRMP filers)
- Even if you have no sales for the month, file a NIL return before the due date — it takes 2 minutes
- If you expect to be delayed, pay the tax amount via challan (PMT-06) before the due date — this avoids the 18% interest even if you file the return late
- Check the GST portal regularly for amnesty schemes — the GST Council periodically waives late fees for older pending returns
Keep your GSTR-1 data ready — use Ozydo for invoices
Every invoice you create in Ozydo is GST-compliant with the right GSTIN, HSN codes, and tax calculations. Export your invoice data to prepare for GSTR-1 filing with zero manual effort.
Start Free GST Invoicing →QRMP Scheme: Should Small Businesses Use It?
The Quarterly Return Monthly Payment (QRMP) scheme is available to taxpayers with aggregate turnover up to ₹5 crore. Key features:
- File GSTR-1 quarterly (instead of monthly) — reducing compliance burden
- File GSTR-3B quarterly — 4 returns per year instead of 12
- But pay tax monthly via PMT-06 challan by the 25th of each month
- Can use IFF (Invoice Furnishing Facility) to upload select B2B invoices monthly — so your buyers can claim ITC promptly
- Opt-in on the GST portal at the beginning of a quarter — it is optional
QRMP is ideal for small traders and service providers with relatively simple GST compliance needs. If you have monthly B2B buyers who need ITC regularly, make sure to use IFF to upload their invoices each month.
Frequently Asked Questions
Is it mandatory to file GSTR-3B every month?
Yes, for monthly filers (turnover above ₹5 crore or those not on QRMP). Even if you had zero transactions, you must file a NIL GSTR-3B by the 20th of the following month. Under the QRMP scheme, GSTR-3B is filed quarterly (but tax is paid monthly).
Can I revise GSTR-3B after filing?
No. GSTR-3B cannot be revised or amended after filing. Errors in GSTR-3B can be corrected in subsequent months (for ITC adjustments) or through GSTR-1 amendments (for outward supply corrections). This is why reviewing carefully before filing is essential.
What happens if GSTR-3B and GSTR-1 figures don't match?
The GST system generates automated scrutiny notices (ASMT-10) when there are significant mismatches between GSTR-1 and GSTR-3B. You will need to respond with an explanation. Consistent large mismatches can trigger detailed audits.
How do I pay the GSTR-3B tax online?
Go to Services → Payments → Create Challan on the GST portal. Select the correct tax head (CGST, SGST, IGST, cess) and amount. Pay via net banking, UPI, NEFT/RTGS, or OTC at an authorised bank. The payment updates your electronic cash ledger, which is then used to offset the tax liability in GSTR-3B.
What is the late fee for GSTR-3B?
₹50 per day for returns with tax liability (₹25 CGST + ₹25 SGST), capped at ₹10,000. For nil returns (no tax), ₹20 per day (₹10 + ₹10), capped at ₹10,000. Additionally, 18% per annum interest applies on unpaid tax from the due date.
What is the difference between GSTR-3B and GSTR-9?
GSTR-3B is the monthly/quarterly summary return filed throughout the year. GSTR-9 is the annual return filed once a year (by December 31) that consolidates all monthly data. GSTR-9 is reconciled against all your GSTR-1 and GSTR-3B filings for the financial year.
📚 Related Guides
Written by the Ozydo Team
Ozydo is India's simplest free GST invoice app for small businesses and freelancers. We write practical guides on invoicing, GST, and business finance to help you get paid faster.
Read more articles →