GST Returns Filing for Beginners — Complete Guide to GSTR-1, GSTR-3B & GSTR-9 (2026)
Getting your GSTIN was the start — but GST compliance is an ongoing obligation that doesn’t pause for slow months, stock issues, or the fact that you’re still figuring out how this all works.
Once you’re registered, you’re required to file GST returns — period. Even if you made zero sales in a month. Even if you’re just starting out and your first order hasn’t arrived yet. Miss a filing deadline, and late fees start accumulating the next day, automatically.
For most new ecommerce sellers and D2C brand founders, understanding the GST return system feels overwhelming at first — mostly because the terminology is confusing and no one explains the whole picture in one place. This guide does exactly that: what each return is, when it’s due, how the QRMP scheme can reduce your filing frequency, what happens when you miss a deadline, and how to avoid the mistakes that cause most new filers their first penalty notice.
The Big Picture: Which Returns You Actually Need to File
GST has multiple return types, but as a regular ecommerce seller or new D2C brand, you’ll primarily deal with three:
| Return | What It Is | Who Files It | Frequency |
|---|---|---|---|
| GSTR-1 | Details of all outward supplies (your sales) | All regular taxpayers | Monthly (11th) or Quarterly (13th) under QRMP |
| GSTR-3B | Summary of sales, ITC claimed, and tax payable | All regular taxpayers | Monthly (20th) or Quarterly (22nd/24th) under QRMP |
| GSTR-9 | Annual return — comprehensive yearly summary | All regular taxpayers (above ₹2 crore turnover — optional below) | Annually (31st December) |
| GSTR-9C | Reconciliation statement certified by CA | Taxpayers with turnover above ₹5 crore | Annually with GSTR-9 |
There are other specialized returns (GSTR-8 for ecommerce operators collecting TCS, GSTR-7 for TDS deductors, etc.) but these don’t apply to the typical seller on a marketplace — marketplaces file GSTR-8 on your behalf for the TCS they collect.
Understanding GSTR-1: Your Sales Statement
What It Is
GSTR-1 contains details of all your outward supplies (sales) for a period — essentially a record of every invoice you raised or transaction you made as a seller. It’s the primary document through which your B2B buyers get their Input Tax Credit (ITC) — your GSTR-1 feeds directly into your buyers’ GSTR-2B, which is what they use to claim ITC on purchases from you.
This makes GSTR-1 accuracy critical beyond your own compliance: errors in your GSTR-1 affect your buyers’ ability to claim ITC, and discrepancies can trigger notices for both parties.
What Goes Into GSTR-1
- All B2B invoices (sales to other registered businesses) — with the buyer’s GSTIN, invoice number, date, value, and tax
- B2C sales (sales to unregistered consumers) — summarized rather than individual invoices for values below ₹2.5 lakh
- Credit notes and debit notes
- Advance receipts
- Export invoices (if applicable)
Due Dates for GSTR-1
Monthly GSTR-1 is due by the 11th of the following month. For example, the GSTR-1 for June sales is due by July 11.
Taxpayers enrolled under the QRMP scheme file GSTR-1 quarterly. The due date is generally the 13th of the month following the quarter. For example, the April–June quarter return is due on 13 July.
Can You Correct a Filed GSTR-1?
Once filed, GSTR-1 cannot be directly revised. However, the GST system allows corrections using GSTR-1A, an amendment form introduced in July 2024. This is critical because incorrect GSTR-1 data flows into your GSTR-3B and affects your ITC claims — and into your buyer’s GSTR-2B, affecting their ITC. Correct it as soon as you spot an error, not at year-end.
Understanding GSTR-3B: Your Tax Payment Statement
What It Is
GSTR-3B is a self-declared summary return filed by all regular taxpayers. It captures:
- Total outward taxable supplies and tax collected
- Total inward supplies and Input Tax Credit available
- Net tax payable after offsetting ITC
- Tax actually paid in cash
Unlike GSTR-1 (which is detail-level), GSTR-3B is summary-level. You’re declaring your overall position for the period rather than invoice-by-invoice details. Payment happens when you file GSTR-3B — the tax due is calculated based on what you declare, and you pay the balance (if any) after offsetting available ITC.
Due Dates for GSTR-3B
GSTR-3B is due on the 20th of the following month for businesses with annual turnover above ₹5 crore.
For businesses with turnover below ₹5 crore under the QRMP scheme, staggered dates apply: the 22nd of the month following the quarter for Category 1 states (such as Maharashtra, Gujarat, Karnataka, Tamil Nadu), and the 24th for Category 2 states (such as Delhi, UP, Punjab, Rajasthan).
Can GSTR-3B Be Revised?
No — GSTR-3B cannot be revised once filed. If you made an error, corrections must be made in the subsequent period’s return. This is why accuracy matters before clicking submit — errors compound forward until corrected.
The QRMP Scheme: Filing Quarterly Instead of Monthly
What It Is
The QRMP scheme allows eligible GST taxpayers to file GSTR-1 and GSTR-3B quarterly while paying tax monthly through Form GST PMT-06. In simple terms, QRMP reduces the regular GSTR-1 and GSTR-3B filing cycle from 24 filings per year to 8.
This is a significant compliance relief for small businesses — instead of two returns every month (GSTR-1 + GSTR-3B = 24 per year), you file just two per quarter (GSTR-1 + GSTR-3B = 8 per year), while still paying tax monthly.
Who Can Use QRMP
All taxpayers whose aggregate annual turnover (PAN-based) is up to ₹5 crore in the current financial year and the preceding financial year (if applicable) and have already filed their last due GSTR-3B return are eligible for the QRMP scheme.
QRMP is not available to:
- Taxpayers with annual turnover exceeding ₹5 crore
- Composition scheme dealers
- Non-resident taxable persons
- Input Service Distributors (ISD)
Monthly Tax Payment Under QRMP — PMT-06
Even though returns are filed quarterly, tax must still be paid monthly. QRMP taxpayers must deposit tax using Form PMT-06 by the 25th of the month following the relevant month. This monthly payment requirement continues even though returns are filed quarterly.
Two methods for calculating your monthly PMT-06 payment:
- Fixed Sum Method: Pay 35% of the tax paid in the last quarter — simple and predictable
- Self-Assessment Method: Calculate actual liability based on that month’s transactions — more accurate but requires reviewing each month’s numbers
Most small businesses prefer the Fixed Sum Method for its simplicity, while businesses with fluctuating turnover benefit from Self-Assessment to avoid overpayment.
Invoice Furnishing Facility (IFF) — Optional But Useful
Under QRMP, if you have B2B buyers who need their ITC reflected in GSTR-2B before the end of the quarter, you can use the Invoice Furnishing Facility (IFF) — an optional mechanism to upload B2B invoices for months 1 and 2 of the quarter (by the 13th of the following month).
B2C invoices cannot be declared in IFF. The IFF limit is ₹50 lakh per month (not per invoice). Using IFF helps your B2B buyers get their ITC earlier without waiting for the quarter-end GSTR-1.
How to Opt Into QRMP
Log in to the GST portal → Services → Returns → Opt-in for Quarterly Return. You can opt in or opt out of the QRMP scheme as per specified timelines. A GST Practitioner cannot opt in/out on behalf of the taxpayer — only the taxpayer can do this action.
You can also have different GSTINs under the same PAN in different schemes — one GSTIN under QRMP and another on monthly filing if your business requires different treatment for different registrations.
Understanding GSTR-9: The Annual Return
What It Is
The GST annual return is a comprehensive summary of all monthly or quarterly returns filed under a financial year. It gives a complete overview of sales, purchases, input tax credit, and tax liabilities.
GSTR-9 is essentially a year-end reconciliation — comparing what you declared through GSTR-1 and GSTR-3B across the year with your actual figures. Discrepancies flagged here can trigger notices if left unexplained.
Who Needs to File GSTR-9
- All regular taxpayers with annual turnover above ₹2 crore — mandatory
- Taxpayers with turnover below ₹2 crore — GSTR-9 filing is optional but still available
GSTR-9C: Reconciliation Statement
Businesses with annual turnover exceeding ₹5 crore also need to file GSTR-9C, a reconciliation statement certified by a Chartered Accountant. Its due date is also 31st December, following the end of the financial year.
GSTR-9C compares your audited financial statements with your GST returns, certified by a CA. This is where significant discrepancies between your books and your filed returns get formally documented and explained.
Due Date for GSTR-9
The annual return GSTR-9 completes the yearly cycle — its due date is 31st December, following the end of the financial year.
For example: GSTR-9 for FY 2025-26 is due by December 31, 2026.
Important: GSTR-9 cannot be revised once filed. Review all annual figures carefully before submission — your CA should reconcile your GSTR-1 data, GSTR-3B data, and actual books before you file.
The Due Dates Calendar — All in One Place
Monthly Filers (Turnover above ₹5 crore)
| Return | Due Date |
|---|---|
| GSTR-1 | 11th of the following month |
| GSTR-3B | 20th of the following month |
| GSTR-9 (Annual) | 31st December |
| GSTR-9C (if turnover > ₹5 crore) | 31st December |
QRMP Filers (Turnover up to ₹5 crore)
| Return/Payment | Due Date |
|---|---|
| PMT-06 (Monthly tax payment — Month 1 of quarter) | 25th of Month 2 |
| PMT-06 (Monthly tax payment — Month 2 of quarter) | 25th of Month 3 |
| IFF (Optional, B2B invoices for Months 1 & 2) | 13th of the following month |
| GSTR-1 (Quarterly) | 13th of month following quarter end |
| GSTR-3B (Quarterly) | 22nd (Category 1 states) or 24th (Category 2 states) of month following quarter |
| GSTR-9 (Annual) | 31st December |
Category 1 vs Category 2 States for QRMP GSTR-3B
Category 1 states (22nd due date): Maharashtra, Gujarat, Karnataka, Tamil Nadu and other major southern and western states. Category 2 states (24th due date): Delhi, UP, Punjab, Rajasthan and other northern and eastern states.
Check the GST portal or your CA to confirm which category applies to your registration state.
Nil Returns — Yes, You Must Still File These
This is one of the most commonly misunderstood aspects of GST compliance among new filers: even if you had zero sales and zero purchases in a month or quarter, you must still file a nil return.
A nil GSTR-3B (showing all zeros) must be filed by the same due date as a regular GSTR-3B. Skipping it because “there’s nothing to report” is not an option — the system treats a missed nil return the same as a missed active return, and late fees apply.
The same applies to GSTR-1: if you had no sales in a period, file a nil GSTR-1 by the due date.
Practical tip: If you’re in a slow period and worried about accidentally missing a nil return deadline, many GST compliance tools and CA dashboards offer automated nil return filing — set this up so that even months with no activity are handled automatically.
Late Fees and Penalties — Exactly What You’ll Pay
Late fees for GSTR-3B are ₹50 per day (₹25 CGST + ₹25 SGST) for regular returns and ₹20 per day (₹10 CGST + ₹10 SGST) for nil returns. Maximum caps apply: ₹2,000 for taxpayers with turnover up to ₹1.5 crore, ₹5,000 for turnover between ₹1.5 crore and ₹5 crore, and ₹10,000 for larger taxpayers.
In addition to late fees, there is an 18% per annum interest charge on any unpaid tax amount from the due date until the actual date of payment. This is separate from the late fee — you pay both.
Quick Late Fee Calculator Example
Say you’re a new seller with turnover below ₹1.5 crore. You miss your GSTR-3B for one month by 30 days and had actual tax liability (not a nil return):
- Late fee: ₹50/day × 30 days = ₹1,500 (capped at ₹2,000 for your turnover slab)
- Interest: 18% per annum on any unpaid tax for those 30 days
Even if the fee is capped, the interest is not — if you had ₹10,000 of unpaid tax, that’s roughly ₹148 in interest for 30 days. Small numbers individually, but they compound quickly if returns stack up.
Consequences Beyond Fees
Missing returns regularly has compounding consequences beyond just late fees:
- GSTIN suspension — repeated non-filing can lead to GSTIN suspension, which immediately blocks your marketplace payouts and e-way bill generation
- ITC chain disruption — if you delay GSTR-1 filing, your B2B buyers can’t claim ITC on purchases from you, which damages your business relationships
- Notice exposure — large discrepancies between GSTR-1 and GSTR-3B, or between your returns and the marketplace’s GSTR-8 filing, can trigger automated scrutiny notices
- Annual return complications — errors and inconsistencies in monthly returns make GSTR-9 reconciliation difficult and may require corrections that attract their own complications
How to Actually File Your GST Returns — Step by Step
All GST return filing is done entirely online at gst.gov.in. Alternatively, data can be prepared offline using Excel-based utilities provided on the portal and uploaded. A growing number of accounting software tools (Tally, Zoho Books, ClearTax, BUSY, etc.) also integrate directly with the GST portal for semi-automated filing.
Filing GSTR-1 (Monthly or Quarterly)
- Log in to the GST portal at gst.gov.in
- Navigate to Services → Returns → Returns Dashboard
- Select the return period (month or quarter) and choose GSTR-1
- Add invoice details:
- B2B invoices (with buyer GSTINs) under Table 4
- B2C Large (above ₹2.5 lakh) under Table 5
- B2C Small (below ₹2.5 lakh) consolidated under Table 7
- Credit/debit notes under Tables 9 and 10
- Export invoices under Table 6
- Generate GSTR-1 summary and verify totals
- File using DSC (for companies/LLPs) or EVC/OTP (for proprietors/partnerships)
Shortcut for ecommerce sellers: most marketplace platforms provide monthly sales reports with HSN-wise breakdowns. Use these reports (from your Amazon/Flipkart/Meesho seller dashboard) as the source data for your GSTR-1 — they align with the period-wise TCS reconciliation in your GSTR-8 data.
Filing GSTR-3B (Monthly or Quarterly)
- Log in to gst.gov.in → Services → Returns → Returns Dashboard
- Select the return period and choose GSTR-3B
- Fill in the key sections:
- Section 3.1: Outward supplies — total taxable value and IGST/CGST/SGST
- Section 4: ITC available — auto-populated from GSTR-2B but editable
- Section 6.1: Tax payable — system calculates based on Sections 3.1 and 4
- Offset ITC against tax payable
- Pay any remaining balance in cash through the Electronic Cash Ledger
- File using DSC or EVC
Important: Compare Section 4 (ITC from GSTR-2B) against your actual purchase records before filing. GSTR-2B shows ITC your suppliers have reported — if a supplier hasn’t filed their GSTR-1 yet, their invoices won’t appear in your GSTR-2B. You can only claim ITC reflected in GSTR-2B.
Filing GSTR-9 (Annual)
- Log in to gst.gov.in → Services → Returns → Annual Return → GSTR-9
- Most fields auto-populate from your monthly GSTR-1 and GSTR-3B filings
- Reconcile: compare auto-populated data with your actual books, audited accounts, and annual purchase/sales register
- Disclose any discrepancies, additional liabilities, or unadjusted ITC
- Pay any additional tax identified during reconciliation
- File — GSTR-9 cannot be revised after filing, so verify completely before submission
GSTR-2B: Your ITC Statement (Not a Return — But Critical)
GSTR-2B is not a return you file — it’s a statement the system generates for you, showing the ITC available based on what your suppliers have filed in their GSTR-1s. An Excel-based utility called the Invoice Management System (IMS) Offline Tool manages the heavy work of invoice reconciliation without needing you to remain logged into the GST portal.
Check your GSTR-2B every month before filing GSTR-3B:
- Verify that all purchases you made are reflected (some suppliers file late, so their invoices show up in the next month’s GSTR-2B)
- Don’t claim ITC on invoices not appearing in GSTR-2B — this is a common trigger for scrutiny notices
- If a major supplier’s invoices are consistently missing, follow up with them — their late GSTR-1 filing is costing you ITC you’re entitled to
Reconciling TCS from Marketplaces
If you sell on Amazon, Flipkart, or Meesho, your marketplace files GSTR-8 monthly, showing the TCS they’ve collected from your sales and deposited against your GSTIN. This TCS shows up in your Electronic Cash Ledger and can be used to offset your GSTR-3B tax liability — effectively reducing how much cash you need to pay at filing time.
Steps to reconcile marketplace TCS:
- Log in to gst.gov.in → Services → Ledger → Electronic Cash Ledger
- Check that TCS deposits from your marketplace(s) appear against your GSTIN
- During GSTR-3B filing, these amounts appear as available credit in your ledger
- Cross-check against your marketplace seller dashboard’s TCS reconciliation report (available in most seller central dashboards)
Discrepancies between what the marketplace reports and what appears in your Electronic Cash Ledger should be flagged immediately — either the marketplace’s GSTR-8 has an error, or your GSTIN was incorrectly linked in their system.
Building a GST Compliance Calendar for the Year
Given the number of due dates and the consequences of missing them, the most practical thing a new seller can do is set up a standing compliance calendar. Here’s a template:
| Date | Task |
|---|---|
| 11th of every month | File GSTR-1 (monthly filers) |
| 13th of Month 1 & 2 of quarter | File IFF (QRMP filers, optional for B2B) |
| 13th of month after quarter end | File GSTR-1 (QRMP filers) |
| 20th of every month | File GSTR-3B + pay tax (monthly filers above ₹5 cr) |
| 22nd or 24th of month after quarter | File GSTR-3B (QRMP filers, per state category) |
| 25th of Month 1 & 2 of quarter | Pay PMT-06 (QRMP filers) |
| 31st December | File GSTR-9 (and GSTR-9C if turnover > ₹5 cr) |
Set calendar reminders 3 days before each deadline — not on the deadline itself. Portal congestion on due dates is real (the GST portal gets heavy traffic near deadlines), and the government has extended deadlines by one day in some cases due to technical issues (e.g., GSTR-3B for March 2026 was extended from April 20 to April 21 via Notification No. 01/2026-Central Tax). Always verify the current due date on the portal or with your CA before filing, as extensions may apply.
Common Mistakes New Filers Make
1. Not filing nil returns. Zero sales doesn’t mean zero obligation. A missed nil return carries the same late fee as a missed active return.
2. Claiming ITC not reflected in GSTR-2B. You can only claim ITC that’s available in GSTR-2B. Claiming more is a compliance risk that can trigger scrutiny.
3. Not reconciling TCS from marketplaces. Unreconciled TCS sits in your Electronic Cash Ledger unused, while you pay cash unnecessarily. Check your ledger before every GSTR-3B filing.
4. Filing GSTR-3B without checking GSTR-1 data. GSTR-3B relies on GSTR-1 data. If your GSTR-1 has errors, they carry forward into GSTR-3B. Always review GSTR-1 before GSTR-3B for the same period.
5. Ignoring the GSTR-1A amendment window. If you discover an error in a filed GSTR-1, use GSTR-1A promptly — not at year-end when corrections become complicated.
6. Missing GSTR-9 because “it’s optional below ₹2 crore.” Even if optional, filing GSTR-9 helps reconcile a full year’s data and often surfaces minor ITC mismatches before they become major issues.
7. Using wrong HSN codes consistently. HSN code errors in GSTR-1 flow into GSTR-9 and create year-end reconciliation nightmares. Verify HSN codes for all your product categories before your first filing.
Should You Use a CA or File Yourself?
For a new seller with simple sales (one or two marketplaces, no exports, no complex B2B transactions), self-filing via the GST portal or a basic accounting tool is entirely feasible. The portal’s auto-population features (GSTR-2B for ITC, GSTR-3B auto-draft from GSTR-1) have improved significantly.
Consider using a CA or GST practitioner if:
- You sell across multiple marketplaces and channels with complex reconciliation
- You have significant B2B sales where ITC accuracy is critical for your buyers
- You have export transactions (separate zero-rated supply treatment)
- Your turnover is above ₹5 crore (GSTR-9C requires CA certification)
- You receive regular marketplace TCS that needs systematic reconciliation
- You’re uncertain about HSN code classification for your product categories
CA fees for regular GST filing typically range from ₹1,000 to ₹3,000 per month for simple returns, to ₹5,000–₹15,000+ for more complex filings — a reasonable investment given that a single GST notice or penalty can cost far more to resolve.
GST return filing is not optional, not seasonal, and not something you can batch-process at year-end. It’s a monthly or quarterly obligation that starts the moment your GSTIN is active — and nil returns must be filed even in months with no activity.
The good news: the system has improved significantly. Auto-population from GSTR-1 into GSTR-2B, the QRMP scheme for smaller sellers, and better accounting tool integrations mean that for a straightforward ecommerce seller, GST returns are manageable with basic discipline and a clear calendar.
Your 4-habit compliance system:
- File GSTR-1 by the 11th (or 13th under QRMP) — your buyers depend on this for their ITC
- Reconcile GSTR-2B before filing GSTR-3B — never claim ITC you can’t see in the statement
- Check your Electronic Cash Ledger for marketplace TCS credits before paying in cash
- File GSTR-3B by the 20th (or 22nd/24th under QRMP) — pay any balance after ITC offset
Do these four things consistently, and GST compliance becomes a system, not a source of anxiety.
Next step: With documentation and GST compliance covered, the next stage in the brand-building journey is packaging — where your product gets its legal labelling, its first impression, and its visual identity. Read our guide: Legal Labelling Requirements for Packaged Products in India.
About This Article
This article reflects the GST return filing framework in India including the QRMP scheme, IFF provisions, GSTR-1A amendment process, and 2026 late fee caps, as understood in mid-2026. GST rules, due dates, scheme eligibility thresholds, and late fee structures are subject to change by GST Council notification. Always verify current due dates on the official GST portal (gst.gov.in) and consult a qualified CA or GST practitioner for advice specific to your business.
