How to file GSTR-1 online: step by step on the GST portal

This guide follows the screens in GSTN’s own manual, in the order you meet them. It is written for the accountant who prepares sales data for GSTR-1, with one addition most filing guides skip: a note on what each step means for the people who bought from you. If you want the meaning of each table first, read GSTR-1 meaning and how it feeds GSTR-2B.

Before you start

• Log-in and signing. You need valid portal credentials. To sign, you need either a DSC or access to the registered mobile number of the primary authorised signatory for EVC. GSTN’s FAQ is not uniform about which entity types must use DSC, so confirm what applies to yours.
• The previous return. Under Rule 59(6), GSTR-1 cannot be furnished if GSTR-3B for the preceding month (for quarterly filers, the preceding tax period) has not been furnished. Section 37(4) also bars it if a previous period’s GSTR-1 is pending.
• Other blocks. The same sub-rule bars filing while an intimation under Rule 88C (DRC-01B) or Rule 88D (DRC-01C) is unanswered, or if bank account details under Rule 10A are not furnished.
• Your data. Invoices and notes of the period, a count of documents issued, and the HSN summary. Each invoice number can be at most 16 characters of letters, digits, dash and slash, and the portal rejects duplicates.

Three ways to prepare the return

GSTN lists three modes: online entry on the portal, uploading invoice and other GSTR-1 data using the Returns Offline Tool, and a third-party application from an Application Software Provider through a GST Suvidha Provider. On the dashboard the first two appear as the PREPARE ONLINE and PREPARE OFFLINE buttons; PREPARE OFFLINE is where you upload the JSON file prepared with the offline tools. If you generate e-invoices, the details auto-populate from the Invoice Registration Portal into the B2B, export and credit/debit note tables and you can edit them.

The filing steps

1. Log in at www.gst.gov.in and click Services → Returns → Returns Dashboard.
2. Select the period. Choose the financial year, quarter and period (month), then click SEARCH.
3. Open the form. In the GSTR1 tile click PREPARE ONLINE. The page “GSTR-1 - Details of outward supplies of goods or services” opens with one tile per table.
4. E-invoice users: download the details. The DOWNLOAD DETAILS FROM E-INVOICES (EXCEL) button gives you what the portal has already pulled in.
5. Add or amend records in the tiles (list below). Records stay in draft, and you can edit or delete them as often as you like until you file.
6. Click GENERATE SUMMARY. Tile counts update only after this click. The status changes from Not filed to Ready to file, and the button is replaced by PROCEED TO FILE/SUMMARY.
7. Click PROCEED TO FILE/SUMMARY and review the consolidated and recipient-wise summary. You can download it as a PDF.
8. Click FILE STATEMENT. On the Returns Filing page tick the declaration and choose the authorised signatory.
9. Sign. Click FILE WITH DSC (then PROCEED, select the certificate, SIGN) or FILE WITH EVC (enter the OTP sent to the authorised signatory’s registered email and mobile, then VERIFY).
10. Confirm. A success message and the ARN appear, the status becomes Filed, and the authorised signatory gets an email and SMS.

What goes in which tile

Table 12 is checked against the other tables. If its tax amounts do not match, the portal shows a warning. If there is B2B data but nothing in the B2B tab of Table 12, it stops you from generating the summary. Confirm tile names on the live form, since GSTN revises them.

Worked example: preparing a September 2026 return

A hardware wholesaler in Rajkot has three B2B invoices, one batch of consumer sales and one credit note for September 2026. All supplies are intra-State at 18 per cent. The return is due on 11 October 2026.

The arithmetic: ₹1,80,000 + ₹95,000 + ₹2,25,000 = ₹5,00,000 taxable, and ₹32,400 + ₹17,100 + ₹40,500 = ₹90,000 tax. Adding the consumer tax of ₹21,600 gives ₹1,11,600, and deducting the credit note’s ₹900 leaves ₹1,10,700. After GSTR-1 is filed, the outward-supply tables of the GSTR-3B draft are pre-filled from it, so compare that draft with this figure before you pay.

Now the buyers’ side. The wholesaler files on 10 October 2026, before the due date. Each B2B invoice becomes a row in the relevant buyer’s September GSTR-2B, generated on 14 October. The buyer of INV/0913 sees ITC of ₹17,100 on the invoice and the credit note in the CDNR sheet, so the net credit is ₹17,100 − ₹900 = ₹16,200. The consumer sales appear in no buyer’s GSTR-2B. Had the wholesaler filed on 15 October, all three invoices would have waited for the October GSTR-2B generated on 14 November, which is what the late fee page works through.

If you are a quarterly (QRMP) filer

Quarterly filers file GSTR-1 once a quarter, by the 13th of the month after the quarter. For the first and second months, the invoice furnishing facility (IFF) is optional. It takes B2B invoices, credit and debit notes to registered persons and their amendments, up to a cumulative ₹50 lakh in each month, and its window closes on the 13th of the next month. Open the Returns Dashboard and select the month to see the IFF form. When you submit an IFF it is frozen, and a submitted IFF must be filed. Whatever you report in IFF is not entered again in the quarterly GSTR-1. IFF invoices reach your buyers’ GSTR-2B once filed, so a quarterly supplier who skips IFF leaves buyers waiting until the quarter’s GSTR-1.

Filing a nil GSTR-1

GSTN says GSTR-1 must be filed even if there is no business activity. On the GSTR-1 page, tick the File Nil GSTR-1 checkbox. If you have saved records, the portal tells you to delete them first, using the RESET button or the delete icon in the tile. Click FILE STATEMENT, then sign as above. For a monthly filer, GSTR-3B and GSTR-1 of the immediately previous month must already be filed. You can download the filed nil return as a PDF.

After you file

• You cannot edit the filed return. Invoices can be modified or deleted only until it is submitted.
• Missed or wrong records in the same period: GSTR-1A, an optional facility that can be filed once for a tax period, any time after GSTR-1 and before GSTR-3B. GSTN’s example shows that ITC for a record added through GSTR-1A reaches the recipient in the next period’s GSTR-2B.
• Errors found later: the amendment tables 9A, 9C and 10 of a later period’s return. For invoices of the previous financial year, GSTN says rectification is not allowed after 30 November of the following financial year.
• Buyer-side effect of amendments: see amended invoices, GSTR-1A and IMS.

When filing fails or gets blocked

• The portal will not accept an invoice: a duplicate invoice number, a number longer than 16 characters, or a recipient GSTIN that was not active on the invoice date.
• The summary will not generate: Table 13 is empty while other tables have data, or the B2B tab of Table 12 is empty while B2B tables have data.
• FILE STATEMENT is not allowed: the previous GSTR-3B or GSTR-1 is pending, or one of the Rule 59(6) blocks listed above applies.
• Missed the date: a late fee applies and a defaulter notice follows. The rates are on the GSTR-1 late fee page.

What your filing means for buyers

Rule 60(7) builds a buyer’s GSTR-2B from the GSTR-1 details furnished in a window that ends on your due date. Section 16(2)(aa) and Rule 36(4) then let the buyer claim ITC only on invoices that appear there. File before the 11th (13th for quarterly filers), and enter each B2B invoice number, date and GSTIN as it is on the tax invoice. Mistyped numbers are the commonest cause of mismatches that buyers have to chase, a theme covered in fixing invoice number mismatches. The buyer’s month is laid out in the 14th to 20th timeline, and the other return in GSTR-1 vs GSTR-3B. The same walk-through for the return where you pay is in GSTR-3B meaning and how GSTR-2B feeds it.

Frequently asked questions

Last checked: 21 October 2026. Sources: GSTN manual: Creation of Outward Supplies Return in GSTR-1, GSTN manual: Filing Nil Form GSTR-1, GSTN GSTR-1 FAQ, GSTN IFF FAQ, CGST Rules, Rule 59, Rule 60, Section 37, Rule 36, Section 16.