GSTR-1: the outward supplies return every GST registrant files

What is GSTR-1 and why does it matter?

GSTR-1 is the statement of outward supplies under section 37 of the CGST Act. It lists every taxable sale you made in the period, broken down by type: B2B invoices with the buyer's GSTIN, large inter-state B2C invoices, other B2C sales in summary, exports, credit and debit notes, advances received and the HSN-wise summary.

It matters for two reasons. First, the B2B invoices you upload flow into your customers' GSTR-2B, which decides how much input tax credit they can claim. A missing or wrong invoice means your customer loses credit and will chase you. Second, the tax liability you declare in GSTR-1 now auto-populates Table 3 of your GSTR-3B, and from the July 2025 tax period that auto-filled liability can no longer be edited in GSTR-3B.

Who has to file GSTR-1?

Every normal taxpayer registered under GST files GSTR-1, even for a month or quarter with no sales. A nil GSTR-1 can be filed through the portal or by SMS. Composition taxpayers, input service distributors, non-resident taxable persons, OIDAR suppliers and persons deducting or collecting tax at source do not file GSTR-1; they have their own returns such as GSTR-4, GSTR-6, GSTR-5, GSTR-5A, GSTR-7 and GSTR-8.

When is GSTR-1 due?

Monthly filers must file by the 11th of the following month. Businesses with aggregate turnover up to ₹5 crore can opt for the Quarterly Return Monthly Payment (QRMP) scheme and file GSTR-1 once a quarter by the 13th of the month after the quarter. QRMP filers can upload B2B invoices for the first two months through the optional Invoice Furnishing Facility so that buyers get credit sooner.

What data do you need?

Prepare a sales register that reconciles with your books before you start. The portal needs invoice-level detail for B2B supplies and for inter-state B2C invoices above ₹1 lakh, plus rate-wise summaries for other B2C sales. Since the GST rate rationalisation of 22 September 2025, check that every invoice carries the correct post-change rate.

• Customer GSTIN, invoice number, date, value, place of supply and rate for each B2B invoice
• Export invoices with shipping bill or bill of export details, and whether tax was paid or supplied under LUT
• Credit and debit notes linked to the original invoices
• Advances received and adjusted, and nil-rated, exempt and non-GST supplies
• HSN-wise summary in Table 12 (4-digit HSN up to ₹5 crore turnover, 6-digit above), plus the document summary in Table 13

Late fee, time limits and common errors

The late fee under section 47 is ₹50 per day (₹25 CGST plus ₹25 SGST), or ₹20 per day for a nil return. It is capped at ₹2,000 for turnover up to ₹1.5 crore, ₹5,000 for ₹1.5-5 crore and ₹10,000 above ₹5 crore, with a ₹500 cap for nil returns. GSTR-1 cannot be filed after three years from its due date, a restriction the portal now enforces.

The most common errors are a wrong buyer GSTIN, B2B sales reported as B2C, wrong place of supply (which swaps IGST and CGST/SGST), missing credit notes and mismatched HSN summaries. Errors found after filing can be fixed through the optional GSTR-1A before GSTR-3B is filed, or in a later GSTR-1 within the time limit in section 37(3).

Not filing GSTR-1 blocks your next GSTR-1 under rule 59(6) if GSTR-3B is pending, keeps your buyers from claiming credit, and repeated non-filing can lead to suspension and cancellation of registration. Refogo's partner professionals can prepare and file GSTR-1 for a fixed fee.

Step by step

1. 1Reconcile the sales register

   Match invoices, credit notes and advances in your books with e-invoice data and the previous period's filings.

2. 2Log in and open GSTR-1

   Go to Returns Dashboard on gst.gov.in, choose the financial year and period, and open GSTR-1.

3. 3Enter or upload invoice data

   Fill the tables directly, upload a JSON from the offline tool, or let e-invoice data auto-populate B2B and export tables.

4. 4Complete HSN and document summaries

   Fill Table 12 with the correct HSN and Table 13 with invoice series issued and cancelled.

5. 5Generate the summary and review

   Click Generate GSTR-1 Summary and compare the totals with your books.

6. 6File with DSC or EVC

   Companies must sign with a digital signature certificate; others can use an Aadhaar OTP-based EVC.