Tax, GST and company law glossary

GSTR-1

The GST return that reports details of outward supplies (sales).

In short

It is filed monthly by the 11th, or quarterly by the 13th under the QRMP scheme. Buyers' input tax credit depends on it.

What it means

GSTR-1 is the GST return in which a registered business reports the details of its outward supplies, that is, its sales. It lists B2B invoices invoice-wise, and B2C sales, exports, credit notes and debit notes in summary or detail as required. The data you report flows into each buyer’s GSTR-2B, which decides how much input tax credit they can claim.

How it works

  • Monthly filers: due by the 11th of the following month.

  • QRMP scheme: businesses with turnover up to ₹5 crore can file quarterly by the 13th of the month after the quarter. They can upload B2B invoices for the first two months of the quarter through the Invoice Furnishing Facility (IFF) by the 13th of the next month so buyers get credit sooner.

  • HSN summary: Table 12 requires an HSN-wise summary of sales, using 4 or 6 digits depending on turnover.

  • Corrections: errors can be amended in GSTR-1A for the same period before filing GSTR-3B, or in a later month’s GSTR-1.

  • Late fee: ₹50 a day (₹25 CGST plus ₹25 SGST), or ₹20 a day for a nil return, subject to a turnover-based cap.

  • Time bar: a return cannot be filed after three years from its due date.

Example

Patel Electricals, a monthly filer in Ahmedabad, makes these sales in October 2026:

B2B sales to registered dealers: ₹8,00,000 + CGST and SGST at 18% = ₹1,44,000

B2C sales to walk-in customers: ₹2,00,000 + GST at 18% = ₹36,000

Total taxable value: ₹10,00,000; total tax: ₹1,80,000

The B2B invoices are uploaded one by one with each buyer’s GSTIN. B2C sales are reported in summary rate-wise. GSTR-1 for October 2026 is due by 11 November 2026. If Patel files on 16 November, it is 5 days late: late fee = 5 x ₹50 = ₹250 (₹125 CGST + ₹125 SGST). More importantly, its buyers may not see the credit in the GSTR-2B for October and may delay payment.

Key points to remember

  • File GSTR-1 before GSTR-3B for the same period; the GSTR-3B liability is auto-filled from it.

  • A wrong buyer GSTIN or invoice value directly affects your customer’s ITC, so reconcile before filing.

  • Not filing GSTR-1 for consecutive periods can block your e-way bill generation and may lead to registration suspension.

  • Report credit notes in the correct period; for credit notes there is a time limit of 30 November following the end of the financial year.

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