What is the due date for filing GSTR-1?

For monthly filers (businesses with turnover above Rs 5 crore), GSTR-1 is due by the 11th of the following month. For example, March 2026 GSTR-1 is due by April 11, 2026. For quarterly filers under the QRMP scheme (turnover up to Rs 5 crore), GSTR-1 is due by the 13th of the month following the quarter. For Q4 FY 2025-26 (January to March 2026), the due date is April 13, 2026. Missing the due date attracts a late fee of Rs 50 per day for regular returns and Rs 20 per day for nil returns, up to a maximum of Rs 10,000 and Rs 500 respectively.

How do I file a nil GSTR-1 return?

Log in to gst.gov.in, go to Returns Dashboard, select the filing period, and click on GSTR-1. At the top of the form, you will see a Nil Return button. Click it, confirm that you had no outward supplies during the period, and file using EVC (electronic verification code sent via OTP to your registered mobile number). The entire process takes less than 2 minutes. You must file nil GSTR-1 even if you had zero sales — skipping it attracts a late fee and can eventually lead to GST registration suspension if you miss multiple consecutive filings.

What is GSTR-1A and when do I need to file it?

GSTR-1A is an amendment return introduced in 2025 that allows you to correct errors in a previously filed GSTR-1 before you file GSTR-3B for the same period. If you discover a wrong invoice amount, missing invoice, incorrect customer GSTIN, or wrong HSN code in your GSTR-1, you can file GSTR-1A to make corrections. This is a significant improvement over the earlier process where corrections had to wait until the next month GSTR-1 or be reported as amendments. GSTR-1A helps ensure your customer input tax credit claims are accurate because corrections reflect immediately in their GSTR-2B.

What is the difference between B2B and B2C in GSTR-1?

B2B (Business to Business) invoices in Table 4 are sales to GST-registered customers. Each B2B invoice is reported individually with the customer GSTIN, invoice number, date, taxable value, and tax amount. B2C (Business to Consumer) invoices are sales to unregistered persons. B2C is further split: B2C Large (Table 5) covers inter-state sales above Rs 2.5 lakh reported invoice-wise with Place of Supply, and B2C Small (Table 7) covers all other B2C sales reported as a consolidated summary by tax rate. The classification matters because B2B data feeds directly into your customer GSTR-2B for ITC claims.

Can I file GSTR-1 without a CA?

Yes, you can file GSTR-1 yourself without a chartered accountant. The GST portal is designed for self-filing. If you use billing software like myBillPlease that auto-generates the GSTR-1 report from your invoices, the process is straightforward — download the Excel file and upload it to the portal. Many small business owners file their own GSTR-1 every month. However, if you have complex transactions, multi-state supplies, or want to ensure zero errors, having a CA review your returns before filing adds a layer of safety. Most CAs charge Rs 500 to Rs 2,000 per month for GST return filing.

What happens if I file GSTR-1 late?

Late filing of GSTR-1 attracts a late fee of Rs 50 per day of delay — Rs 25 for CGST and Rs 25 for SGST. The maximum cap is Rs 10,000 per return (Rs 5,000 CGST + Rs 5,000 SGST). For nil returns, the late fee is Rs 20 per day with a cap of Rs 500. Beyond the financial penalty, late GSTR-1 filing affects your customers because they cannot see your invoices in their GSTR-2B until you file. This blocks their ITC claims and can strain business relationships. If you miss filing for multiple consecutive periods, the GST officer can suspend your registration.

How does myBillPlease help with GSTR-1 filing?

myBillPlease auto-generates your GSTR-1 report from the invoices you create during the month. Every invoice is automatically classified as B2B or B2C based on whether the customer has a GSTIN. B2C invoices are further sorted into Large and Small based on inter-state flag and invoice value. The HSN summary aggregates all sales by HSN code with tax breakdowns. You download the report as an Excel file that matches the GST portal upload format exactly. Before downloading, the system flags potential issues like invoices without HSN codes or customers with invalid GSTINs. The report covers the complete GSTR-1 — Tables 4, 5, 7, 9, 11, and 12 — in a single download.

GST Returns & Filing

How to File GSTR-1 in 2026: Step by Step Guide

GSTR-1 is the return for outward supplies — every GST-registered business must file it. This guide walks you through the complete filing process, due dates, formats, and how to avoid common mistakes.

Himanshu23 March 2026 · 6 min read · updated 6 September 2026

Two business professionals collaborating with a laptop and calculator in a modern office.

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Key takeaways

GSTR-1 reports every outward supply: B2B invoices in Table 4, B2C Large in Table 5, B2C Small in Table 7, notes in Table 9, HSN summary in Table 12.
Monthly filers (turnover above Rs 5 crore) file by the 11th; QRMP filers file by the 13th of the month after the quarter.
Late filing costs Rs 50 per day up to Rs 10,000 (Rs 20 and Rs 500 for nil), and your customers cannot claim ITC until you file.
GSTR-1A, new in 2025, lets you correct a filed GSTR-1 before the matching GSTR-3B is filed.

What is GSTR-1 and Who Needs to File It?

GSTR-1 is a monthly or quarterly return that every registered GST taxpayer in India must file. It contains details of all outward supplies — meaning all the sales invoices, credit notes, debit notes, and advances received during the filing period. Your customers use your GSTR-1 data to claim input tax credit, so accuracy is critical.

Every business registered under GST must file GSTR-1, regardless of whether you had any sales during the period. If you had zero sales, you still file a nil return. The only exceptions are businesses under the composition scheme (they file CMP-08 instead) and Input Service Distributors (they file ISD returns).

Filing GSTR-1 correctly and on time is important for three reasons: your customers depend on it for their ITC claims, late filing attracts a penalty of Rs 50 per day (Rs 20 for nil returns), and consistent late filing can lead to your GST registration being suspended. We built the GSTR-1 report in myBillPlease to generate automatically from your invoices — so you always have filing-ready data without manual compilation.

This guide covers everything you need to know about GSTR-1 filing in 2026, including the step-by-step process on the GST portal, the invoice format requirements, due dates, nil return filing, and the new GSTR-1A amendment form. Use our free GST calculator to verify tax amounts before filing.

GSTR-1 Due Dates 2026

Monthly filers file by the 11th. Quarterly filers (QRMP) file by the 13th of the month after the quarter.

	Monthly Filing	QRMP (Quarterly Filing)
Who qualifies	Turnover > Rs 5 crore	Turnover ≤ Rs 5 crore (optional)
January 2026	Due: Feb 11	Due: Apr 13 (Q4 FY25-26)
February 2026	Due: Mar 11	—
March 2026	Due: Apr 11	—
April 2026	Due: May 11	Due: Jul 13 (Q1 FY26-27)
May 2026	Due: Jun 11	—
June 2026	Due: Jul 11	—
Late fee	Rs 50/day (max Rs 10,000)	Rs 50/day (max Rs 10,000)
Nil return late fee	Rs 20/day (max Rs 500)	Rs 20/day (max Rs 500)

Step-by-Step: How to File GSTR-1 on the GST Portal

Follow these steps to file your return correctly

Step 1: Log in to the GST portal at gst.gov.in with your GSTIN and password
Step 2: Go to Returns → Returns Dashboard → Select the filing period (month or quarter)
Step 3: Click GSTR-1 tile → Prepare Online (or upload JSON if you have the data ready)
Step 4: Fill in Table 4 — B2B invoices (sales to registered businesses with customer GSTIN)
Step 5: Fill in Table 5 — B2C Large (inter-state sales above Rs 2.5 lakh to unregistered persons)
Step 6: Fill in Table 7 — B2C Small (all other B2C sales — both intra-state and inter-state below Rs 2.5 lakh)
Step 7: Fill in Table 9 — Credit notes and debit notes issued during the period
Step 8: Fill in Table 11 — Advances received for which invoices have not been issued yet
Step 9: Fill in Table 12 — HSN summary of outward supplies with quantity, value, and tax amounts
Step 10: Review all entries, verify totals match your records, and click Submit → File with DSC or EVC

GSTR-1 Format: Understanding the Tables

GSTR-1 has multiple tables, each for a different type of supply. Understanding which invoices go where is the most common source of filing errors. Here is a breakdown:

Table 4 — B2B Supplies: All invoices issued to GST-registered businesses. Each invoice must include the customer's GSTIN, invoice number, date, taxable value, and tax amounts (CGST, SGST, or IGST). This is the most important table because your customer's ITC depends on it.

Table 5 — B2C Large: Inter-state sales to unregistered persons where the invoice value exceeds Rs 2.5 lakh. These are reported invoice-wise with the Place of Supply (state code).

Table 7 — B2C Small: All remaining B2C sales — intra-state sales of any value and inter-state sales below Rs 2.5 lakh. These are reported as a consolidated summary by rate, not invoice-wise.

Table 9 — Credit and Debit Notes: Any credit notes (refunds, returns) or debit notes (additional charges) issued during the period. For B2B credit notes, you must include the original invoice reference.

Table 12 — HSN Summary: Aggregate summary of all supplies grouped by HSN code. Required for all businesses — 4-digit HSN for turnover up to Rs 5 crore, 6-digit for above. Use our HSN code directory to find the correct codes.

If you use myBillPlease, the GSTR-1 report auto-classifies your invoices into B2B, B2C Large, and B2C Small based on customer GSTIN and invoice amount. Download the Excel file and upload it to the portal — no manual sorting needed.

How to File GSTR-1 Nil Return

If you had no outward supplies during the filing period — no sales invoices, no credit notes, no advances — you must still file a nil GSTR-1. Skipping it attracts a late fee of Rs 20 per day up to Rs 500.

Filing a nil return is simple: log in to the GST portal, go to Returns Dashboard, select the period, click GSTR-1, and click the Nil Return button at the top. Confirm and file with EVC (electronic verification code via OTP). The entire process takes under 2 minutes.

Common scenario: a new business registers for GST in January but starts operations in March. For January and February, file nil GSTR-1 returns. From March onwards, file regular returns with your invoice data.

A rising search query is GSTR-1A — this is the new amendment return introduced in 2025. If you discover errors in a filed GSTR-1 (wrong invoice amount, missing invoice, wrong GSTIN), you can file GSTR-1A to correct them before the GSTR-3B for that period is filed. Previously, corrections had to wait until the next month's GSTR-1. GSTR-1A makes corrections faster and keeps your customer's ITC claims accurate.

Common GSTR-1 Filing Mistakes to Avoid

Wrong Customer GSTIN

Typing errors in customer GSTIN mean their ITC won't match. Always verify GSTIN before issuing invoices. myBillPlease validates GSTIN format automatically when you add a customer.

Missing B2B Invoices

If you skip a B2B invoice in GSTR-1, your customer sees a mismatch in their GSTR-2B. They can't claim ITC until you report it. Include every B2B invoice — even small amounts.

Wrong Place of Supply

Inter-state vs intra-state classification determines IGST vs CGST+SGST. Getting this wrong means wrong tax calculation and filing errors. Use GSTIN state codes to determine the correct place of supply.

HSN Code Errors

Wrong or missing HSN codes in Table 12 attract a penalty of Rs 50 per invoice. Use the correct 4 or 6 digit code based on your turnover. Check the HSN code directory at mybillplease.com/hsn.

Filing After Due Date

Late filing attracts Rs 50 per day for regular returns and Rs 20 per day for nil returns. Set a calendar reminder for the 11th of every month. Or use billing software that reminds you when GSTR-1 data is ready.

Not Reconciling with Books

Your GSTR-1 total should match your sales register. Before filing, compare the GSTR-1 report with your actual invoices. Any mismatch means missing or duplicate entries.

Skip Manual Data Entry — Auto-Generate GSTR-1

The biggest pain point in GSTR-1 filing is compiling invoice data into the right format. If you use paper bills or Excel, this means manually sorting hundreds of invoices into B2B, B2C Large, B2C Small, and HSN categories. One missing invoice or wrong classification can cause ITC mismatches for your customers.

myBillPlease eliminates this entirely. Every invoice you create is automatically classified by the system — B2B invoices tagged by customer GSTIN, B2C invoices sorted by state and amount, HSN codes attached from your product catalog. At month-end, click Reports → GSTR-1 → Download Excel. The file is ready for portal upload.

The system also highlights potential issues before you file — invoices without HSN codes, customers with invalid GSTINs, and tax calculation mismatches. Fix these in the report before filing, not after a GST notice arrives.

GSTR-3B report is also auto-generated — your total output tax, input tax credit from purchase invoices, and net payable are calculated automatically. Filing both returns takes minutes instead of hours.

Frequently asked questions

What is the due date for filing GSTR-1?: For monthly filers (businesses with turnover above Rs 5 crore), GSTR-1 is due by the 11th of the following month. For example, March 2026 GSTR-1 is due by April 11, 2026. For quarterly filers under the QRMP scheme (turnover up to Rs 5 crore), GSTR-1 is due by the 13th of the month following the quarter. For Q4 FY 2025-26 (January to March 2026), the due date is April 13, 2026. Missing the due date attracts a late fee of Rs 50 per day for regular returns and Rs 20 per day for nil returns, up to a maximum of Rs 10,000 and Rs 500 respectively.
How do I file a nil GSTR-1 return?: Log in to gst.gov.in, go to Returns Dashboard, select the filing period, and click on GSTR-1. At the top of the form, you will see a Nil Return button. Click it, confirm that you had no outward supplies during the period, and file using EVC (electronic verification code sent via OTP to your registered mobile number). The entire process takes less than 2 minutes. You must file nil GSTR-1 even if you had zero sales — skipping it attracts a late fee and can eventually lead to GST registration suspension if you miss multiple consecutive filings.
What is GSTR-1A and when do I need to file it?: GSTR-1A is an amendment return introduced in 2025 that allows you to correct errors in a previously filed GSTR-1 before you file GSTR-3B for the same period. If you discover a wrong invoice amount, missing invoice, incorrect customer GSTIN, or wrong HSN code in your GSTR-1, you can file GSTR-1A to make corrections. This is a significant improvement over the earlier process where corrections had to wait until the next month GSTR-1 or be reported as amendments. GSTR-1A helps ensure your customer input tax credit claims are accurate because corrections reflect immediately in their GSTR-2B.
What is the difference between B2B and B2C in GSTR-1?: B2B (Business to Business) invoices in Table 4 are sales to GST-registered customers. Each B2B invoice is reported individually with the customer GSTIN, invoice number, date, taxable value, and tax amount. B2C (Business to Consumer) invoices are sales to unregistered persons. B2C is further split: B2C Large (Table 5) covers inter-state sales above Rs 2.5 lakh reported invoice-wise with Place of Supply, and B2C Small (Table 7) covers all other B2C sales reported as a consolidated summary by tax rate. The classification matters because B2B data feeds directly into your customer GSTR-2B for ITC claims.
Can I file GSTR-1 without a CA?: Yes, you can file GSTR-1 yourself without a chartered accountant. The GST portal is designed for self-filing. If you use billing software like myBillPlease that auto-generates the GSTR-1 report from your invoices, the process is straightforward — download the Excel file and upload it to the portal. Many small business owners file their own GSTR-1 every month. However, if you have complex transactions, multi-state supplies, or want to ensure zero errors, having a CA review your returns before filing adds a layer of safety. Most CAs charge Rs 500 to Rs 2,000 per month for GST return filing.
What happens if I file GSTR-1 late?: Late filing of GSTR-1 attracts a late fee of Rs 50 per day of delay — Rs 25 for CGST and Rs 25 for SGST. The maximum cap is Rs 10,000 per return (Rs 5,000 CGST + Rs 5,000 SGST). For nil returns, the late fee is Rs 20 per day with a cap of Rs 500. Beyond the financial penalty, late GSTR-1 filing affects your customers because they cannot see your invoices in their GSTR-2B until you file. This blocks their ITC claims and can strain business relationships. If you miss filing for multiple consecutive periods, the GST officer can suspend your registration.
How does myBillPlease help with GSTR-1 filing?: myBillPlease auto-generates your GSTR-1 report from the invoices you create during the month. Every invoice is automatically classified as B2B or B2C based on whether the customer has a GSTIN. B2C invoices are further sorted into Large and Small based on inter-state flag and invoice value. The HSN summary aggregates all sales by HSN code with tax breakdowns. You download the report as an Excel file that matches the GST portal upload format exactly. Before downloading, the system flags potential issues like invoices without HSN codes or customers with invalid GSTINs. The report covers the complete GSTR-1 — Tables 4, 5, 7, 9, 11, and 12 — in a single download.