GSTR-1 Due Date: Complete Filing Guide for 2026

If you sell goods or services and you're registered under GST, GSTR-1 is the return that tells the government — and your buyers — exactly what you sold and to whom. It's arguably the most consequential GST return for your customers, because the data you file here flows directly into their input tax credit. Miss it or get it wrong, and you'll hear about it from them before you hear about it from the tax department.

This guide covers who has to file GSTR-1, the current due dates for both monthly and quarterly (QRMP) filers, what late filing actually costs, and how to file it.

What is GSTR-1?

GSTR-1 is a monthly or quarterly statement of outward supplies — every sale invoice, credit note, debit note, and export you've issued in the period, reported at an invoice level for B2B transactions and at a summary level for most B2C transactions. There's no tax payment attached to GSTR-1 itself; you report the tax liability here, but you actually pay tax when you file GSTR-3B. GSTR-1 exists purely to get accurate sales data into the system so your buyers' input tax credit and your own GSTR-3B auto-population line up correctly.

Who Must File

Every normal (regular scheme) GST-registered person has to file GSTR-1 for every tax period, even if there were zero sales — in which case you file a nil return. Filing is mandatory regardless of turnover.

A few categories file different returns instead and are not required to file GSTR-1:

• Composition scheme taxpayers (they file GSTR-4)
• Input Service Distributors (ISD)
• Non-resident taxable persons (they file GSTR-5)
• OIDAR (online information and database access/retrieval) service providers
• Persons required to deduct TDS or collect TCS under GST (they file GSTR-7 / GSTR-8 respectively)

Due Date

The due date depends on whether you file monthly or under the QRMP (Quarterly Return, Monthly Payment) scheme. QRMP is available to registered persons with PAN-based aggregate annual turnover up to ₹5 crore in the preceding financial year; if you cross ₹5 crore during a quarter, you lose QRMP eligibility from the following quarter. Everyone above ₹5 crore turnover must file monthly; taxpayers at or below ₹5 crore can choose either monthly or QRMP filing.

The IFF lets QRMP taxpayers upload B2B invoices for the first two months of a quarter so their buyers can claim input tax credit without waiting for the quarterly GSTR-1. It's optional and covers B2B invoices only — the full quarterly GSTR-1 (covering the whole quarter, including B2C data) is still due by the 13th after quarter-end regardless of whether IFF was used.

These are the standard statutory due dates under GST return-filing rules. The GST Council does occasionally extend deadlines for specific tax periods (usually due to portal issues), so if you're filing close to the deadline, cross-check the exact date for your specific period on the GST portal before you rely on it.

Late Fee and Penalty

GSTR-1 doesn't carry an "interest" charge the way GSTR-3B does, since no tax is paid with it — but it does attract a late fee for every day of delay, capped by your prior-year turnover, under the CGST Act's late fee provisions (Section 47) as currently rationalized by CBIC notification:

• Regular return with sales to report: ₹50/day (₹25 CGST + ₹25 SGST), subject to the caps below
• Nil return: ₹20/day (₹10 CGST + ₹10 SGST), capped at ₹500 total

Maximum late fee caps, based on aggregate turnover in the preceding financial year:

There's also a hard cutoff worth knowing about: since the 2025 rollout of the three-year time-bar rule under the Finance Act, 2023, you cannot file a GST return — including GSTR-1 — more than three years after its original due date. Once that window closes, the portal blocks filing for that period permanently, and there's currently no routine mechanism to reopen it. This is a rolling deadline per return period, not an annual one, so old pending returns are worth clearing well before the three-year mark.

Late fees shown here are the standard rationalized rates; the government has periodically run amnesty schemes waiving fees for specific past periods, so always check the GST portal for any amnesty notification that might apply to your case before paying.

How to File

1. Log in to the GST portal (gst.gov.in) with your credentials.
2. Go to Services → Returns → Returns Dashboard, select the relevant financial year and tax period, and open GSTR-1 (or IFF, if you're a QRMP filer submitting month 1 or 2 data).
3. Enter invoice-level details for B2B supplies and summary details for B2C supplies, credit/debit notes, exports, and amendments to earlier periods — either manually, via the offline utility/JSON upload, or through a GST-compliant billing/accounting tool.
4. Preview the summary, confirm the auto-computed totals for each table match your books.
5. Submit and file the return using a Digital Signature Certificate (DSC) or Electronic Verification Code (EVC/OTP).

Frequently Asked Questions

Do I need to file GSTR-1 if I had no sales in a period?

Yes. You still have to file a nil GSTR-1 for that period; it just attracts a lower late fee cap (₹500) if filed late.

Can I file GSTR-1 quarterly if my turnover is below ₹5 crore?

You can opt into QRMP if your PAN-based aggregate turnover was up to ₹5 crore in the preceding financial year. It's optional — you can still choose to file monthly instead.

What's the difference between IFF and quarterly GSTR-1?

IFF is an optional facility for QRMP filers to upload B2B invoices for months 1 and 2 of a quarter, due on the 13th of the following month, so buyers get timely credit. It doesn't replace the quarterly GSTR-1, which still has to be filed for the full quarter (including month 3 and all B2C data) by the 13th after the quarter ends.

What happens if I miss the three-year filing window?

The GST portal permanently blocks filing for that return period once three years have passed from its original due date, per rules effective from late 2025. There is presently no standard route to file it after that, so it's worth clearing any long-pending GSTR-1 filings well before the cutoff.

Sources

• ClearTax – GSTR-1 Filing Guide
• ClearTax – QRMP Scheme Guide
• SAG Infotech – GSTR-1 Due Dates 2026
• Official GSTN FAQ on QRMP Scheme and IFF
• TaxGuru – CBIC Notification 20/2021-Central Tax on GSTR-1 Late Fee
• IndiaFilings – GST Returns 3-Year Filing Limit Rule

Always confirm the exact due date and late fee for your specific filing period on the official GST portal (gst.gov.in) before relying on the figures above, as deadlines are occasionally extended and amnesty schemes can change applicable late fees.