What is GSTR-1 and Who Must File It?
GSTR-1 is the Statement of Outward Supplies — the return in which every GST-registered person declares all taxable outward supplies (sales) made during a given period. It serves as the primary source of supply-side data in the GST system. When a supplier files GSTR-1, the data automatically flows into the purchasing customer's GSTR-2B, which is the auto-generated ITC statement the customer uses to claim Input Tax Credit.nnEvery registered person under GST is required to file GSTR-1 unless they are specifically exempt — composition scheme taxpayers file CMP-08 and GSTR-4 instead of GSTR-1. Input Service Distributors file GSTR-6. Tax Deductors file GSTR-7. Tax Collectors (like e-commerce operators) file GSTR-8. All regular taxpayers — manufacturers, traders, service providers, and mixed-supply businesses — file GSTR-1 either monthly or quarterly depending on their turnover and whether they have opted for the QRMP scheme.nnThe significance of GSTR-1 extends beyond the filer's own compliance — it is the foundation of the entire GST ITC ecosystem. Every business's ability to claim ITC depends on their suppliers filing accurate and timely GSTR-1 returns. A supplier who files late or incorrectly directly damages their customers' ITC eligibility, creating downstream compliance issues and potential disputes. This interdependency makes GSTR-1 filing accuracy and timeliness a matter of both self-compliance and business relationship management.
GSTR-1 Due Dates FY 2025-26 — Monthly and Quarterly
The GSTR-1 filing frequency and due dates depend on the taxpayer's annual aggregate turnover and whether they are enrolled in the QRMP (Quarterly Return Monthly Payment) scheme.nnFor monthly filers — taxpayers with turnover above Rs.5 crore in the previous financial year and those below Rs.5 crore who have not opted for QRMP — GSTR-1 is due by the 11th of the month following the return period. For FY 2025-26: April 2025 GSTR-1 by 11 May 2025, May 2025 by 11 June 2025, and so on for each month. The 11th deadline is standard throughout the year.nnFor QRMP scheme filers — taxpayers with turnover up to Rs.5 crore who have opted for quarterly filing — GSTR-1 is filed quarterly. The quarterly GSTR-1 due dates for FY 2025-26 are: Q1 (April to June 2025) by 13 July 2025, Q2 (July to September 2025) by 13 October 2025, Q3 (October to December 2025) by 13 January 2026, and Q4 (January to March 2026) by 13 April 2026. QRMP taxpayers must also file Invoice Furnishing Facility (IFF) for the first two months of each quarter by the 13th of the following month to allow B2B buyers to receive ITC promptly without waiting for the quarterly GSTR-1.
| Taxpayer Type | Turnover | Filing Frequency | Due Date |
|---|---|---|---|
| Monthly filer | Above Rs.5 crore | Monthly | 11th of following month |
| QRMP — quarterly GSTR-1 | Up to Rs.5 crore (opted QRMP) | Quarterly | 13th of month after quarter |
| QRMP — IFF (Invoice Furnishing Facility) | Up to Rs.5 crore (opted QRMP) | Monthly (first 2 months of quarter) | 13th of following month |
| Nil GSTR-1 (no supplies made) | Any turnover | Same as applicable frequency | Same deadline applies — file nil |
| Q1 FY 2025-26 (quarterly) | Up to Rs.5 crore | April-June 2025 | 13 July 2025 |
| Q2 FY 2025-26 (quarterly) | Up to Rs.5 crore | July-September 2025 | 13 October 2025 |
| Q3 FY 2025-26 (quarterly) | Up to Rs.5 crore | October-December 2025 | 13 January 2026 |
| Q4 FY 2025-26 (quarterly) | Up to Rs.5 crore | January-March 2026 | 13 April 2026 |
GSTR-1 Tables — What Goes Where
GSTR-1 contains multiple tables each capturing a different category of outward supply. Understanding which invoices go in which table prevents misclassification that can cause ITC mismatches for buyers.nnTable 4 is for B2B supplies — invoices issued to other registered businesses. Each invoice must be entered with the buyer's GSTIN, invoice number and date, place of supply, taxable value, and GST amount split into CGST/SGST (for intrastate) or IGST (for interstate). These entries directly populate the buyer's GSTR-2B. Table 5 is for B2B supplies with amendments — correcting previously filed B2B invoices. Table 6A is for exports — each export invoice with shipping bill details, port code, and foreign currency value. Table 6B is for supplies to SEZs.nnTable 7 is for B2C large invoices — interstate supplies to unregistered persons where the invoice value exceeds Rs.2.5 lakh. Table 8 is for B2C small invoices — all other sales to unregistered consumers, entered as consolidated state-wise summaries rather than invoice-by-invoice. Table 9 covers advance receipts and adjustments for advance payments received. Table 11 contains HSN summary — a mandatory summary of supplies grouped by HSN code showing total value, tax rate, and GST for each HSN. Table 12 covers documents issued during the period including tax invoices, credit notes, debit notes, and revised invoices. Getting the table-wise classification right is essential — B2B invoices entered in B2C tables will not generate ITC for buyers.
How to File GSTR-1 Online — Step by Step
GSTR-1 is filed on the GST portal at gst.gov.in. Step 1: Log in using GSTIN and password. Navigate to Returns Dashboard. Select the Financial Year and Return Period. Click on GSTR-1. Step 2: Choose the filing mode. For businesses with a large number of invoices, the offline tool (downloaded from gst.gov.in) is more practical — prepare the data in the Excel format, upload the JSON file generated by the offline tool to the portal. For businesses with few invoices, online entry directly on the portal is simpler. Step 3: Fill in all applicable tables — B2B invoices in Table 4, exports in Table 6A, B2C large in Table 7, B2C consolidated in Table 8, and HSN summary in Table 11. Step 4: Preview the GSTR-1 draft using the Preview button to verify totals and identify any errors before submission. Step 5: Submit the return — click Submit, then File Using DSC (Digital Signature Certificate) for companies and LLPs, or File Using EVC (Electronic Verification Code sent by OTP) for proprietorships and partnerships.nnAfter filing, the data is locked — errors can only be corrected in subsequent return periods through amendment tables (Table 9A, 9B, 9C) or through the new GSTR-1A facility before GSTR-3B is filed. The portal generates an Application Reference Number (ARN) confirming successful submission. GSTR-1 once filed auto-updates the GSTR-2A of all customers whose GSTINs are cited in the B2B table.
Consequences of Late or Non-Filing of GSTR-1
Late filing of GSTR-1 has direct consequences for both the filer and their customers. For the filer, a late fee of Rs.50 per day (Rs.25 CGST + Rs.25 SGST) applies for returns with taxable supplies. For nil returns — where no supplies were made — the late fee is Rs.20 per day (Rs.10 CGST + Rs.10 SGST). The maximum late fee for GSTR-1 is Rs.10,000 per return (Rs.5,000 CGST + Rs.5,000 SGST) for returns with supplies. Periodic amnesty schemes have waived accumulated late fees for habitual defaulters, but these cannot be relied upon as a compliance strategy.nnFor customers of a late GSTR-1 filer, the direct impact is that their GSTR-2B for the period does not reflect the missing invoices — they cannot claim ITC on those purchases until the supplier eventually files. If the supplier consistently files late, it creates a recurring ITC delay for all their customers. In competitive business relationships, suppliers with poor GSTR-1 filing records are increasingly being penalised by buyers who insist on compliance track records before continuing business arrangements.nnAdditionally, non-filing of GSTR-1 blocks the filing of GSTR-3B for the subsequent month — the GST portal enforces sequential filing. If GSTR-1 for March is not filed, the April GSTR-3B filing is blocked. This cascading blockage can create compounding late fees and compliance breakdowns for businesses that fall behind on GSTR-1 filings.
