How to File GSTR-1 on the GST Portal: Step-by-Step Guide (2026)

GSTR-1 is the return where you report your sales: invoice by invoice for business customers and in summary for consumers. Your buyers' input tax credit depends on it, and since July 2025 the tax liability it creates flows into GSTR-3B and can't be edited there. Here's how to file it on the GST portal, step by step.

Who files GSTR-1, and when

Composition taxpayers don't file GSTR-1; they file CMP-08 and GSTR-4. For how GSTR-1 links to GSTR-3B, see GSTR-1 vs GSTR-3B.

Before you start

• Your sales register for the period, with each B2B invoice's GSTIN, number, date, value, rate and place of supply
• Credit and debit notes issued
• HSN-wise totals of sales (B2B and B2C separately)
• The number ranges of invoices, notes and challans you issued, including cancelled ones
• Your login, and the registered mobile for the EVC OTP (or a DSC if you're required to use one)

Steps to file GSTR-1 online

1. Log in at gst.gov.in and go to Services → Returns → Returns Dashboard.
2. Select the period: financial year, quarter and month, then click Search.
3. Open GSTR-1: on the GSTR-1 tile, click Prepare Online. (If you have many invoices, you can upload a JSON file prepared in the GST offline tool or from your billing software.)
4. Fill each applicable table (see the table below). Add B2B invoices one by one or by upload; enter B2C (Others) as rate-wise totals per state.
5. Check auto-populated data. If you issue e-invoices, their details are auto-filled into the relevant tables. Review them rather than entering them again.
6. Fill Table 12 (HSN summary) and Table 13 (documents issued). Select HSN codes from the dropdown; the portal validates the B2B tab against your B2B tables.
7. Generate the summary: click Generate GSTR-1 Summary, then Preview to download the draft and check totals against your books.
8. File: click Proceed to File/Summary, tick the declaration, choose the authorised signatory, and file with EVC (OTP) or DSC.
9. Save the acknowledgement: note the ARN and download the filed return for your records.

What goes in each table

Table names follow the GST portal. Not every table applies to every business; leave the ones that don't apply empty.

How to file a nil GSTR-1 (online or by SMS)

GSTR-1 must be filed for every period, even with no sales. Normal taxpayers (including SEZ units and developers) and casual taxpayers file it as a nil return when, for that month or quarter, there are:

• no outward supplies, including reverse-charge supplies, zero-rated supplies and deemed exports;
• no amendments to supplies reported in an earlier return;
• no credit or debit notes to declare or amend; and
• no advances received for services to declare or adjust.

You can file it from the 1st of the month after the period (for April, from 1 May; for the April–June quarter, from 1 July). Source: GSTN's nil GSTR-1 FAQs.

Steps to file a nil GSTR-1 online

1. Log in at gst.gov.in and go to Services → Returns → Returns Dashboard. Pick the financial year, quarter and period and click Search.
2. On the GSTR-1 tile, click Prepare Online.
3. Tick File Nil GSTR-1 at the top of the GSTR-1 page. If any data is already saved (auto-populated e-invoice details, for example), the portal won't allow nil filing: delete those records or click Reset, then tick the box again.
4. Click File Statement, tick the declaration, choose the authorised signatory and file with EVC (OTP) or DSC.
5. Note the ARN. GSTN's user manual adds that the previous period's GSTR-1 and GSTR-3B must already be filed.

Steps to file a nil GSTR-1 by SMS

1. From the authorised signatory's mobile number registered on the GST portal, send NIL R1 <GSTIN> <period> to 14409. The period is MMYYYY: for April 2026, 042026. Quarterly filers use the last month of the quarter (April–June 2026 = 062026).
2. If the return qualifies, you get a six-digit verification code by SMS. It works once and expires in 30 minutes.
3. Send a new SMS to 14409: CNF R1 <code>.
4. The ARN arrives by SMS and on your registered email. Check it under Services → Returns → Track Return Status.

• SMS filing doesn't work if anything is saved in GSTR-1 on the portal for that period, or if two authorised signatories share the same mobile number.
• Send HELP R1 to 14409 for the format. Nil GSTR-3B works the same way with 3B in place of R1.
• Late fee: a nil GSTR-1 filed late costs ₹20 a day (₹10 CGST + ₹10 SGST), up to ₹500 (Notification 20/2021-Central Tax). Estimate yours with the GST late fee calculator.

After filing: corrections and GSTR-3B

• Found a mistake? Use GSTR-1A, available after you file GSTR-1 and before you file GSTR-3B for the same period, to add or correct details.
• GSTR-3B liability is auto-filled from GSTR-1/1A and, from the July 2025 period, can't be edited in GSTR-3B (Table 3.2 is locked from November 2025). Correct it at the GSTR-1/1A stage. Details: GSTR-3B lock explained.
• Later corrections go into the amendment tables of a later GSTR-1, within the time limits in the law.
• Don't miss the three-year limit: a return can't be filed more than three years after its due date; the portal enforces this from the November 2025 tax period.

Common GSTR-1 mistakes

How VelBooks helps

Every bill in VelBooks carries the buyer's GSTIN, HSN code, rate and place of supply, so your GSTR-1 data, including the HSN summary, is ready from your billing. GSTR filing and return management works from the same data. Need an HSN code? Try the HSN code finder.

Sources

• GST portal
• GST portal news and advisories (incl. Table 12 HSN changes)
• Notification 12/2024-Central Tax (B2C Large limit)
• GSTN FAQs: filing nil GSTR-1 through SMS
• GSTN manual: filing nil GSTR-1 online
• GSTN advisory: single-click nil filing of GSTR-1 (PDF)
• Notification 20/2021-Central Tax (GSTR-1 late fee)
• CBIC

This article is general information, not legal or tax advice. Rules change; check the official sources above or consult your tax adviser.