How to File GSTR-1 in 2026: Complete Guide to Due Dates, Format, Late Fees & Rules

GSTR-1 is a monthly or quarterly return that every GST-registered business must file to report all outward supplies, meaning your sales. Filing of GSTR-1 is not optional. Miss it and your buyers lose their Input Tax Credit (ITC). Whether you are a trader in Delhi, a service provider in Bengaluru, or a manufacturer in Surat, this form follows you. The GSTR-1 due date for monthly filers is the 11th of the following month. Businesses with turnover up to Rs. 5 crore can opt for quarterly filing under the QRMP scheme and file by the 13th of the month after the quarter ends. This guide covers everything: what is GSTR 1, the format of GSTR-1, how to file GSTR-1 online, GSTR-1 late fee, and all 2026 updates you need to know.

What is GSTR-1 and Who Should File It?

GSTR-1 is an outward supply return. Every registered taxpayer under GST must file it to declare all sales made during a month or quarter. It is the foundation of the GST return system because GSTR-1 data flows directly into GSTR-3B and auto-populates GSTR-2B for your buyers. A mistake here creates mismatches that buyers notice when they try to claim ITC.

Practically every regular GST taxpayer must file form GSTR-1, even if there were zero sales in the period. However, some categories are exempt from filing GSTR-1:

●        Input Service Distributors (ISD)

●        Composition Dealers, who file CMP-08 instead

●        Non-resident taxable persons, who use GSTR-5

●        OIDAR service providers under Section 14 of the IGST Act

●        Taxpayers liable to deduct TDS or collect TCS under GST

 

If you are a regular taxpayer and none of the above applies, GSTR-1 filing is mandatory for you regardless of sales volume.

Important: Nil Return Mandatory

Even if you had no sales in a month, you still need to file a nil GSTR-1. You can do this quickly via SMS on the GST portal, which saves time compared to logging in and filing manually.

GSTR-1 Due Date in 2026: Monthly and Quarterly Filing Dates

The GSTR-1 filing date depends on your annual aggregate turnover. Monthly filers (turnover above Rs. 5 crore) must submit by the 11th of the next month. Under the QRMP scheme (turnover up to Rs. 5 crore), the quarterly filing of GSTR-1 is due by the 13th of the month after the quarter ends. Here is the full schedule for 2026-27:

2026 Rule Update: As per the amendment to Section 37 of the CGST Act, taxpayers cannot file GSTR-1 beyond three years from the original due date. The GST portal now permanently blocks such late returns. File on time.

To track your return status after filing, you can check your GST filing status on gstregistration.co.

What is the Format of GSTR-1? Tables Explained Simply

The format of GSTR-1 has 13 tables, each covering a different type of outward supply. Here is a quick breakdown of what goes where:

2026 HSN Update: Manual HSN entry in Table 12 is no longer allowed. As per GSTN advisory dated January 22, 2025, taxpayers must now select HSN codes from the drop-down menu. Table 12 is also split into B2B and B2C tabs. If you have B2B supplies in other tables, you cannot leave the B2B tab of Table 12 blank.

How to File GSTR-1 Online: Step-by-Step Process

Filing GSTR-1 online on the GST portal takes 10 to 20 minutes once you have your invoices ready. Here is the step-by-step process:

1.  Log in to gst.gov.in using your credentials.

2.  Go to Returns > Returns Dashboard.

3.  Select the financial year and return period.

4.  Click PREPARE ONLINE under GSTR-1.

5.  Fill in the applicable tables: B2B invoices in Table 4, B2C in Table 7, HSN in Table 12, etc.

6.  Use GSTR-1 JSON to Excel / offline tool if you have bulk invoices to upload.

7.  Preview the return and check for errors.

8.  Submit using EVC (OTP) or DSC (Digital Signature).

9.  File before 11th (monthly) or 13th (quarterly) of the relevant month.

 

Pro tip: Upload invoices regularly during the month rather than all at once on the due date. Bulk uploads near the deadline slow down the portal and increase error risk. Also, for the GSTR-1 download, go to Services > Returns > GSTR-1 and choose the relevant period to download filed data.

For help with filing or if you need to file your GST returns through a professional, gstregistration.co provides expert-assisted services.

What is the Difference Between GSTR-1, GSTR-3B, and GSTR-1A?

A very common question from business owners: Is GSTR-1 a purchase or sale return? It is a sales return. Here is how the three returns differ:

GSTR-1 must be filed before GSTR-3B from January 1, 2022 onwards. If you skip GSTR-1, the portal will not let you file GSTR-3B. Your buyers will also not see their ITC in GSTR-2B.

GSTR-1A is a correction return introduced via CGST Notification dated July 10, 2024. You can use it to amend errors in GSTR-1 for the same period before you submit GSTR-3B. After GSTR-3B is submitted, amendments can only be made in the next period.

GSTR-1 Late Fee and Penalty: What Happens if You Miss the Date?

Missing the filing of GSTR-1 due date attracts a late fee under Section 47 of the CGST Act. The fee applies from the day after the due date until you actually file. Here is the fee structure:

Penalty Alert: Beyond Late Fee

Late fee is not the only consequence. If GSTR-1 is not filed, the GST officer can block your GSTIN under Rule 86A, restricting ITC usage in your electronic credit ledger. Repeat defaults can also trigger scrutiny or cancellation notices.

There is no interest on late GSTR-1 filing itself (interest applies only to GSTR-3B for delayed tax payment). But the indirect cost, such as your buyer losing ITC, can damage business relationships fast.

For questions about penalty notices, you can check the GST notices section on gstregistration.co.

Is GSTR-1 Filing Monthly or Quarterly? Understanding the QRMP Scheme

GSTR-1 is both, depending on your turnover. Businesses with aggregate annual turnover above Rs. 5 crore must file monthly. Those at or below Rs. 5 crore can opt for the QRMP (Quarterly Return Monthly Payment) scheme and file GSTR-1 quarterly.

Under QRMP, the monthly GSTR-1 due date concept changes. You file one GSTR-1 per quarter by the 13th of the following month. But you still pay tax monthly via a fixed sum or self-assessment. For the first two months of a quarter, you can upload B2B invoices through the Invoice Furnishing Facility (IFF) to let your buyers claim ITC without waiting for the quarterly GSTR-1.

 

Frequently Asked Questions 

Q1: What is GSTR-1?

GSTR-1 is a monthly or quarterly GST return in which every registered taxpayer reports all outward supplies, meaning all sales of goods and services. It is the primary return for declaring your sales to the GST department. Buyers use this data to verify ITC in GSTR-2B.

Q2: What is the process of filing GSTR-1?

Log in to gst.gov.in, go to Returns Dashboard, select the period, and click Prepare Online under GSTR-1. Fill in the relevant tables such as B2B invoices in Table 4, B2C in Table 7, and HSN in Table 12. Preview the data, then submit using EVC or DSC. Upload invoices in advance to avoid last-minute issues.

Q3: What is the GSTR-1 due date for monthly and quarterly filers?

Monthly filers must file GSTR-1 by the 11th of the following month. Under the QRMP scheme, quarterly filers must file by the 13th of the month after the quarter ends. For example, GSTR-1 for April to June 2026 is due by 13 July 2026.

Q4: Is GSTR-1 filing monthly or quarterly?

Both options exist. Businesses with turnover above Rs. 5 crore file monthly. Those with turnover up to Rs. 5 crore can opt for quarterly filing under the QRMP scheme. The scheme must be opted in at the start of the quarter.

Q5: What is the late fee for late filing of GSTR-1?

The late fee is Rs. 50 per day (Rs. 25 CGST + Rs. 25 SGST) for regular returns. For nil GSTR-1, it is Rs. 20 per day. The maximum late fee for GSTR-1 is Rs. 10,000 for businesses with turnover above Rs. 5 crore. Smaller businesses face a lower cap based on their turnover slab.

Q6: Is there any penalty for non-filing of GSTR-1?

Yes. Non-filing attracts the late fee mentioned above. Beyond that, continued default can lead to GST notice, blocking of your electronic credit ledger under Rule 86A, and in serious cases, cancellation of GST registration. Your buyers also lose the ability to claim ITC, which damages your business relationships.

Q7: What is the difference between GSTR-1 and GSTR-3B?

GSTR-1 is a sales return where you report the details of every invoice. GSTR-3B is a summary return where you report total tax liability, ITC claimed, and net tax payable. GSTR-1 must be filed before GSTR-3B. No tax payment is made through GSTR-1 itself; payment happens through GSTR-3B.

Q8: Can I file GSTR-1 after the due date?

Yes, but with a late fee. From 2026, you cannot file GSTR-1 more than three years after its original due date. The portal blocks such filings permanently. So while late filing is allowed, there is a time limit beyond which the option disappears.

Q9: Is GSTR-1 a purchase or sale return?

GSTR-1 is a sales return. It reports all outward supplies, meaning goods and services sold by you. Your purchases are auto-reflected in GSTR-2B based on what your suppliers report in their GSTR-1.

Q10: Who should file GSTR-1?

Every regular GST-registered taxpayer must file GSTR-1, including those with zero sales. Composition dealers, ISDs, non-resident taxable persons, and OIDAR service providers are exempt from GSTR-1 and file different returns instead.

Q11: What is GSTR-1A?

GSTR-1A is an amendment return for GSTR-1. Introduced via CGST Notification dated July 10, 2024, it allows you to correct errors in GSTR-1 for the same period before you file GSTR-3B. Once GSTR-3B is submitted, corrections can only be made in the next period.

Q12: What is the last date to file GSTR-1 for October 2026?

Monthly filers must file by 11 November 2026. QRMP filers covering the July to September 2026 quarter would have already filed by 13 October 2026. The next quarterly due date for QRMP filers will be 13 January 2027 for the October to December 2026 quarter.

Q13: Can I download GSTR-1 once filed?

Yes. Log in to the GST portal, go to Services > Returns > GSTR-1, and select the relevant period. You can download the filed return in JSON or PDF format. The GSTR-1 JSON to Excel conversion is also available for offline reconciliation.

Final Word

GSTR-1 is more than a filing requirement. It is the document that determines whether your buyers can claim ITC or not. Get it right, file it on time, and your business relationships stay intact. The filing of GSTR-1 and GSTR-3B work as a pair. GSTR-1 first, then GSTR-3B. Missing either creates a chain of problems.

The 2026 updates, particularly the three-year hard block on late filings and the mandatory HSN dropdown, mean the rules are tightening. Uploading invoices during the month rather than at the last minute will save you from portal errors and missed deadlines.

If you need help with GST registration or have received a notice for non-filing, visit gstregistration.co for professional support.

 

About the Author

Hemant Mali | SEO Intern

GST compliance expert who transforms complex tax regulations into simple, actionable steps. He is dedicated to helping business owners navigate GST registration and tax filing with ease, ensuring seamless compliance for every entrepreneur.