GST Returns: GSTR-1, GSTR-3B, GSTR-9 Filing Guide

Key Takeaways

• GSTR-1 (outward supply details) is filed monthly by the 11th or quarterly under QRMP scheme; GSTR-3B (summary return with tax payment) is filed monthly by the 20th.
• GSTR-9 (annual return) consolidates all monthly/quarterly returns and is due by 31st December of the following financial year.
• Late filing attracts Rs. 50/day (Rs. 25 CGST + Rs. 25 SGST) for GSTR-3B and GSTR-1, capped at 0.04% of turnover per return.
• The QRMP scheme (Quarterly Return Monthly Payment) is available for taxpayers with turnover up to Rs. 5 crore.
• GSTR-2B auto-populated ITC statement is generated on the 14th of each month based on supplier filings.

GSTR-1 -- Outward Supply Statement

Section 37 of the CGST Act mandates every registered person to furnish details of outward supplies in GSTR-1.

| Aspect | Details | |--------|---------| | What it contains | B2B invoices, B2C (large) invoices, amendments, credit/debit notes, exports, nil-rated/exempt supplies | | Due date (Monthly) | 11th of the following month | | Due date (QRMP) | 13th of the month following the quarter | | IFF (Invoice Furnishing Facility) | QRMP taxpayers can upload B2B invoices in months 1 and 2 of each quarter by the 13th |

GSTR-1 data flows into GSTR-2B of the recipient, making accurate and timely filing critical for the entire ITC chain.

GSTR-3B -- Summary Return with Payment

Section 39 requires filing GSTR-3B, a self-assessed summary return where taxpayers declare output liability, claim ITC and make tax payment.

| Aspect | Details | |--------|---------| | Tables | 3.1 (outward supplies), 4 (ITC), 5 (exempt/nil-rated), 6.1 (payment) | | Due date (Monthly) | 20th of the following month | | Due date (QRMP) | 22nd/24th of the month following the quarter (staggered by state) |

Critical: GSTR-3B is a payment return. Non-filing blocks ITC for recipients and triggers interest under Section 50.

GSTR-9 -- Annual Return

Filed under Section 44, GSTR-9 is a comprehensive annual consolidation.

| Part | Content | |------|---------| | Part II | Outward supplies -- taxable, exempt, nil-rated, zero-rated | | Part III | ITC -- claimed, reversed, ineligible | | Part IV | Tax paid -- cash and ITC utilisation | | Part V | Amendments and adjustments | | Part VI | Other information -- demands, refunds, HSN summary |

Due date: 31st December following the financial year. GSTR-9 is mandatory for taxpayers with turnover exceeding Rs. 2 crore (GSTR-9C reconciliation statement was self-certified from FY 2020-21 onwards).

Worked Example -- Late Fee Calculation

Scenario: A taxpayer in Gujarat (turnover Rs. 1.5 crore) files GSTR-3B for October 2025 on 15th December 2025 (55 days late).

| Component | Calculation | Amount | |-----------|-------------|--------| | Late fee (CGST) | 55 days x Rs. 25 | Rs. 1,375 | | Late fee (SGST) | 55 days x Rs. 25 | Rs. 1,375 | | Maximum cap | 0.04% x Rs. 1,50,00,000 / 12 months | Rs. 500 (CGST) + Rs. 500 (SGST) | | Actual late fee payable | Capped amount | Rs. 1,000 |

The cap of 0.04% is applied on turnover in the state for that return period. Additionally, interest @ 18% p.a. applies on the net tax liability from the due date till actual payment under Section 50.

Landmark Judgement

Case: Pennar Engineered Building Systems Ltd. v. Union of India Court: Telangana High Court Year: 2023 Ruling: The Court struck down the restriction preventing taxpayers from filing GSTR-1 when GSTR-3B of the previous period was pending. It held that Rule 59(6) of CGST Rules, which blocked GSTR-1 filing, was ultra vires of Sections 37 and 39 of the CGST Act as the Act did not contemplate such a linkage. Impact: Reinforced that subordinate legislation (Rules) cannot exceed the parent statute, protecting taxpayers from being locked out of the filing system for procedural delays.

Expert Tip

Always reconcile GSTR-1 outward supplies with GSTR-3B liability before filing. Mismatches between GSTR-1 and GSTR-3B are the top trigger for departmental notices under Section 61 (scrutiny) and Section 73/74 (demand proceedings). Our CAs recommend maintaining a monthly reconciliation workbook mapping every invoice to its return disclosure.

Section Interconnect

• Previous: Chapter 3 -- Input Tax Credit details the ITC that flows into Table 4 of GSTR-3B.
• Next: Chapter 5 -- GST Audit & Assessment covers how return data feeds into audit and assessment proceedings.
• Related: Chapter 6 -- E-Invoicing & E-Way Bill discusses how e-invoice data auto-populates GSTR-1.

Frequently Asked Questions

Q1: What is the QRMP scheme and who is eligible? The Quarterly Return Monthly Payment scheme allows taxpayers with aggregate turnover up to Rs. 5 crore to file GSTR-1 and GSTR-3B quarterly instead of monthly. Tax must still be paid monthly using PMT-06 challan. The Invoice Furnishing Facility (IFF) allows uploading B2B invoices in non-quarter months.

Q2: Is GSTR-9 mandatory for all taxpayers? GSTR-9 is mandatory for regular taxpayers with turnover exceeding Rs. 2 crore. Composition taxpayers file GSTR-9A instead. Taxpayers below Rs. 2 crore are currently exempted via notification, though this exemption is reviewed annually.

Q3: Can I revise a filed GSTR-3B? No. GST law does not provide for revision of returns. Errors must be corrected through amendments in subsequent period returns. Over-reported liability can be adjusted in the next GSTR-3B, while under-reported liability should be corrected with interest and shown in subsequent filings.

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Disclaimer: This article is for educational purposes only and does not constitute legal or professional advice. GST laws are subject to frequent amendments. Readers should consult qualified CAs or tax professionals before acting on any information provided here.