GSTR-1 and GSTR-3B: Filing Guide

Every GST-registered business in India must file periodic returns. The two most important returns are GSTR-1 (reporting sales) and GSTR-3B (summarising tax liability and paying it). This guide explains what each return contains, who must file it, the exact due dates, how to file on the GST portal, and the consequences of missing deadlines.

Key Takeaways

• GSTR-1 reports your outward supplies (sales invoices); GSTR-3B reports your net tax liability and settles payment
• Monthly filers (turnover > ₹5 crore): GSTR-1 due 11th, GSTR-3B due 20th of the following month
• QRMP filers (turnover ≤ ₹5 crore): GSTR-1 due 13th of the month after the quarter; GSTR-3B due 22nd or 24th
• Late fee for GSTR-3B: ₹50/day (₹20/day for nil return), maximum ₹5,000 per return
• Always reconcile with GSTR-2B before claiming ITC in GSTR-3B

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GSTR-1: Statement of Outward Supplies

What is GSTR-1?

GSTR-1 is a details return — it is not a payment return. You use it to report every outward supply (sale) you made during the period. Your customers who are GST-registered businesses see these invoices in their GSTR-2B (auto-populated ITC statement). If you do not file GSTR-1, your buyers cannot claim ITC, which harms your business relationships.

What is Reported in GSTR-1?

Table	What to Report
Table 4	B2B invoices (supplies to GST-registered recipients) — every invoice with GSTIN of buyer
Table 5	B2C large invoices (inter-state supply > ₹2.5 lakh to unregistered buyers)
Table 6	Zero-rated supplies (exports and supplies to SEZ)
Table 7	B2C small invoices (intra-state or inter-state ≤ ₹2.5 lakh to unregistered) — consolidated state-wise
Table 8	Nil-rated, exempt, and non-GST outward supplies
Table 9	Amendments to B2B invoices from previous periods
Table 10	Amendments to B2C large invoices
Table 11	Advances received and adjustments
Table 12	HSN-wise summary of outward supplies
Table 13	Documents issued (invoices, credit/debit notes, advance receipts)

GSTR-1 Due Dates

Taxpayer Category	Frequency	Due Date
Turnover > ₹5 crore (preceding FY)	Monthly	11th of the following month
QRMP scheme (turnover ≤ ₹5 crore)	Quarterly	13th of the month following the quarter
IFF (Invoice Furnishing Facility for QRMP)	Monthly (optional for B2B)	13th of the following month

QRMP quarterly due dates example:

• Q1 (Apr–Jun): 13 July
• Q2 (Jul–Sep): 13 October
• Q3 (Oct–Dec): 13 January
• Q4 (Jan–Mar): 13 April

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GSTR-3B: Summary Return with Tax Payment

What is GSTR-3B?

GSTR-3B is a self-declaration summary return. Unlike GSTR-1, it does not contain invoice-level details. Instead, you declare:

• Total value of outward taxable supplies and tax collected
• Total ITC available (from GSTR-2B) and ITC claimed
• Net tax payable (output tax minus ITC)
• Tax actually paid

Important: GSTR-3B is both a return and a payment document. You must pay any net tax liability (after ITC set-off) before or while filing GSTR-3B; otherwise the return is not submitted.

What is Reported in GSTR-3B?

Table	What to Report
Table 3.1	Outward supplies — taxable, zero-rated, nil-rated, exempt, and non-GST turnover
Table 3.2	Inter-state supplies to unregistered/composition/UIN holders
Table 4	Eligible ITC (from GSTR-2B) — separated into goods, services, capital goods, import of goods
Table 5	Exempt, nil-rated, and non-GST inward supplies
Table 6	Payment of tax (CGST, SGST, IGST, Cess) — through ITC and cash ledger

GSTR-3B Due Dates

Taxpayer Category	Frequency	Due Date
Turnover > ₹5 crore in preceding FY	Monthly	20th of the following month
QRMP — Category X states	Quarterly	22nd of the month following the quarter
QRMP — Category Y states	Quarterly	24th of the month following the quarter

Category X states (22nd): Chhattisgarh, MP, Gujarat, Maharashtra, Karnataka, Goa, Kerala, TN, Telangana, Andhra Pradesh, D&N Haveli and Daman & Diu, Puducherry, Andaman & Nicobar Islands, Lakshadweep.

Category Y states (24th): HP, Punjab, Uttarakhand, Haryana, Rajasthan, UP, Bihar, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Assam, West Bengal, Jharkhand, Odisha, J&K, Ladakh, Chandigarh, Delhi.

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Step-by-Step: How to File GSTR-1 on the GST Portal

1. Log in to the GST portal at www.gst.gov.in with your credentials
2. Go to Services > Returns > Returns Dashboard
3. Select the Financial Year and Return Filing Period (month or quarter)
4. Click Prepare Online under GSTR-1 (or upload JSON for bulk filing)
5. Fill in each table:
   • For B2B sales: Enter GSTIN of each buyer, invoice date, number, taxable value, GST rate, and tax amount. This auto-populates the buyer's GSTR-2B.
   • For B2C sales: Aggregate by state for small invoices; enter individually for large inter-state invoices above ₹2.5 lakh.
   • For exports: Enter shipping bill details, port code, and export currency.
   • For HSN summary: Add HSN-wise consolidated data (mandatory if turnover ≥ ₹5 crore; optional for smaller taxpayers)
6. Click Save after filling each table
7. Click Preview to download a draft
8. Once satisfied, click Submit → File with DSC or EVC

After filing, GSTR-1 cannot be revised — errors must be corrected through amendments in the next period's return (Table 9 and Table 10 for B2B and B2C large invoices respectively).

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

1. Log in and navigate to Services > Returns > Returns Dashboard
2. Select the return period and click Prepare Online under GSTR-3B
3. Table 3.1 — Outward Supplies:
   • Enter total taxable value and tax for CGST, SGST, IGST, Cess
   • Separate rows for zero-rated (exports), nil-rated/exempt, and non-GST supplies
   • These figures should match your GSTR-1 for the period
4. Table 4 — ITC Claims:
   • Download your GSTR-2B (available from the 14th of the following month)
   • Reconcile GSTR-2B against your purchase records
   • Enter ITC claimed — only claim ITC that is in GSTR-2B unless you have the right to claim it under the transitional provisions
5. Table 6 — Tax Payable:
   • The system auto-calculates: Output tax − ITC = Net payable
   • First, offset using Electronic Credit Ledger (ITC credits)
   • Remaining balance must be paid from Electronic Cash Ledger
6. Pay Tax if Applicable:
   • If cash ledger balance is insufficient, click Create Challan, pay via net banking or UPI, and wait for credit to reflect
7. Verify and File:
   • Click Preview, review the declaration
   • File using DSC (companies and LLPs) or EVC (OTP to registered mobile/email)

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Reconciliation: GSTR-1, GSTR-3B, and GSTR-2B

Reconciliation is a critical practice that many smaller businesses skip, leading to notices and ITC reversals later.

GSTR-1 vs GSTR-3B Reconciliation

Your total outward supply figures in GSTR-3B (Table 3.1) should match the summary of GSTR-1 for the same period. Differences may arise due to:

• B2C turnover aggregated differently
• Advances received (taxable in GSTR-3B) not yet invoiced in GSTR-1
• Timing differences in filing

GSTR-2B Reconciliation Before ITC Claim

Never claim ITC in GSTR-3B without checking GSTR-2B first. ITC that is not in GSTR-2B (because your supplier has not filed their GSTR-1) can be claimed only in later months once it appears, or through the Rule 37A mechanism. Claiming ITC not in GSTR-2B can result in demand, interest, and penalty.

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Late Fees and Consequences

Late Fee for GSTR-1

Return Type	Late Fee Per Day	Maximum
Regular GSTR-1 (with supplies)	₹50/day (₹25 CGST + ₹25 SGST)	₹5,000 per return
Nil GSTR-1 (no supplies)	₹20/day (₹10 + ₹10)	₹500 per return

Late Fee for GSTR-3B

Return Type	Late Fee Per Day	Maximum
Regular GSTR-3B	₹50/day (₹25 CGST + ₹25 SGST)	₹5,000 per return
Nil GSTR-3B	₹20/day (₹10 + ₹10)	₹500 per return

Additionally, interest at 18% per annum applies on the tax outstanding after the due date. This interest is calculated from the day after the due date until actual payment.

Consequences of Not Filing

• ITC blocked for your buyers: Your B2B customers cannot claim ITC until you file GSTR-1
• Return blocking: If GSTR-3B is not filed for 2 consecutive periods, the GST portal may block your GSTR-1 filing
• Registration cancellation: Sustained non-filing can lead to the GST officer initiating cancellation of your GSTIN
• Assessment under Section 62: If returns are not filed, the officer can assess tax on a best-judgment basis
• Bank account attachment: In cases of large outstanding tax, the department can attach bank accounts under Section 79

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Practical Tips for Smooth GST Filing

1. Reconcile purchase invoices monthly against GSTR-2B rather than waiting for year-end
2. Upload B2B invoices to GSTR-1 promptly — your buyers' GSTR-2B is generated from your filings
3. Maintain a GST ledger in your accounting software tracking output tax, ITC, and net payable each month
4. Keep credit notes and debit notes correctly categorised — issue credit notes for returns/discounts before September of the following year (Section 34 time limit)
5. Check the GST portal's amnesty schemes — the government periodically waives late fees for older pending returns

For complex GST compliance including e-invoicing, e-way bills, ITC reversal calculations, and annual return (GSTR-9), professional assistance can prevent costly errors. Our GST return filing service handles monthly and quarterly return preparation and filing for businesses of all sizes.

Proper bookkeeping and accounting practices — maintaining month-wise purchase and sales registers, reconciling bank statements regularly — make GST return preparation significantly faster and less error-prone.

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This article is for general informational purposes only and does not constitute professional advice. GST rules, forms, and due dates are subject to change based on government notifications and GST Council decisions. Consult a qualified tax professional for guidance specific to your business.