How to File GSTR-1 Online: Step-by-Step Guide
GSTR-1 is the first return in the GST filing cycle, and getting it right sets the tone for everything that follows, including your GSTR-3B and your buyers' input tax credit. This guide walks through filing GSTR-1 on the GST portal, table by table, along with the offline tool, QRMP filing, amendments, and common mistakes to avoid.
If you need help preparing and submitting your returns, explore LegalDev India’s GST return filing services.
What Is GSTR-1?
GSTR-1 is the monthly or quarterly return where a registered taxpayer reports all outward supplies, meaning sales made during the tax period. It is filed under Section 37 of the CGST Act and covers B2B invoices (sales to GST-registered buyers), B2C supplies (sales to unregistered customers), credit and debit notes, exports, nil-rated and exempt supplies, and amendments to invoices reported in earlier periods. The data you file in GSTR-1 flows directly into your buyers' GSTR-2B, which they use to claim input tax credit, and it also feeds into your own GSTR-3B. Accuracy here matters well beyond your own return.
Who Should File GSTR-1?
Every regular taxpayer registered under GST must file GSTR-1, whether or not there were any sales during the period.
Monthly GSTR-1 Filers
Taxpayers with aggregate turnover above ₹5 crore, and smaller taxpayers who have not opted for the QRMP scheme, file GSTR-1 every month for the previous month's sales.
Quarterly GSTR-1 Filers Under QRMP
Taxpayers with turnover up to ₹5 crore can opt for the QRMP scheme and file GSTR-1 once every quarter instead of monthly. They can still report B2B invoices early each month using the optional Invoice Furnishing Facility, covered later in this guide. For exact due dates for both monthly and QRMP filing, refer to our separate GST return due dates guide.
Taxpayers Not Required to File GSTR-1
Composition scheme taxpayers, input service distributors, non-resident taxable persons, and TDS/TCS deductors do not file GSTR-1. They file their own specific returns, such as GSTR-4, GSTR-6, GSTR-5, or GSTR-7/8, instead.
Read our guide to GST return types to understand which forms apply to different taxpayer categories.
Prerequisites Before Filing GSTR-1 Online
A little preparation before you log in saves a lot of correction work later.
Active GSTIN and Portal Login
Make sure your GSTIN is active and you have your GST portal username and password ready. If a director or partner needs to digitally sign the return, keep the Digital Signature Certificate (DSC) accessible as well.
Sales Register, Invoices and Credit/Debit Notes
Finalise your sales register for the period, including every tax invoice, credit note, and debit note issued. Each entry should have the invoice number, date, buyer details, taxable value, and tax amount already calculated.
HSN Codes and Tax Rate Details
Confirm the correct HSN or SAC code and GST rate for every product or service sold. Businesses with turnover up to ₹5 crore need at least a 4-digit HSN code, and those above ₹5 crore need a 6-digit code.
B2B, B2C, Export and Nil-Rated Supply Data
Sort your sales into categories before you start: B2B (buyer has a GSTIN), B2C (buyer has no GSTIN), exports, and nil-rated or exempt supplies. Having this classification ready in advance makes filling the portal's tables much faster.
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How to File GSTR-1 Online: Step-by-Step Process
Once your data is ready, filing on the GST portal follows a fixed sequence of steps.
Step 1: Log in to the GST Portal
Go to www.gst.gov.in and log in with your username, password, and the captcha shown on screen.
Step 2: Go to Services → Returns → Returns Dashboard
From the top menu, click Services, then Returns, then Returns Dashboard, to reach the page where you select your filing period.
Step 3: Select Financial Year, Return Period and GSTR-1
Choose the financial year and the month or quarter you are filing for, click Search, and then select GSTR-1 from the returns shown for that period.
Step 4: Prepare Online or Upload Invoice Data
You can either enter invoice details directly on the portal (Prepare Online) or upload a JSON file generated through the offline tool if you have a large number of invoices. For taxpayers covered under e-invoicing, eligible B2B invoice details are auto-populated from the Invoice Registration Portal within a couple of days.
Step 5: Enter Invoice Details in the Relevant Tables
Open each relevant table, such as B2B Invoices, B2C Large, B2C Others, Exports, or Credit/Debit Notes, and add your invoice-wise or summary data as applicable. Save each table after entry.
Step 6: Add HSN Summary and Documents Issued
Fill the HSN-wise summary of your outward supplies in Table 12, and record the documents issued during the period, such as invoice series and any cancelled invoice numbers, in Table 13.
Step 7: Generate GSTR-1 Summary
Once all tables are filled and saved, click Generate GSTR-1 Summary. The portal consolidates your entries into recipient-wise, state-wise, and HSN-wise totals.
Step 8: Preview, Verify and Submit GSTR-1
Download the summary in PDF format and check it carefully against your sales register. Once you are satisfied the figures are correct, tick the declaration checkbox and click Submit. Submission locks the return for final filing.
Step 9: File With EVC or DSC
Complete the filing using an Electronic Verification Code (EVC) sent to your registered mobile and email, or using a Digital Signature Certificate if your business type requires DSC, such as companies and LLPs.
Step 10: Download the Filed GSTR-1 Acknowledgement
After successful filing, download the acknowledgement receipt and keep it with your records. This confirms your GSTR-1 for the period has been filed.
You can also check your GST return filing status to review the filing status for the relevant tax period.
GSTR-1 Tables Explained for Online Filing
GSTR-1 has several tables, but most small and regular taxpayers only need a handful of them regularly.
Table 4: B2B Invoices
This table captures invoice-wise details of every sale made to a GST-registered buyer, including the buyer's GSTIN, invoice number, date, taxable value, and tax amount.
Table 5: B2C Large Invoices
This covers interstate sales to unregistered customers where a single invoice value exceeds ₹1 lakh. This threshold applies from the August 2024 tax period onward, replacing the earlier ₹2.5 lakh limit.
Table 6: B2C Others
Although listed later in the form sequence, note that smaller B2C sales (both intrastate and interstate below the B2C Large threshold) are reported as a state-wise summary rather than invoice by invoice.
Table 7: B2CL and Exports
Export invoices, whether with or without payment of tax, are reported separately in this section, along with the shipping bill details where applicable.
Table 8: Nil-Rated, Exempted and Non-GST Supplies
Sales of goods or services that are nil-rated, wholly exempt, or outside the scope of GST are reported here as a summary total, not invoice by invoice.
Table 9: Amendments to B2B Invoices
If you need to correct a B2B, B2C Large, or export invoice already reported in an earlier period's GSTR-1, you make the correction here in the period you discover the error, not by editing the original filed return.
Table 10: Amendments to B2C Invoices
Similarly, corrections to earlier B2C Others entries are reported here as a net adjustment in the current period.
Table 11: Credit and Debit Notes
Credit notes and debit notes issued during the period, against both B2B and B2C invoices, are reported here, along with a reference to the original invoice where applicable.
Table 12: HSN Summary
From the May 2025 tax period, this table is split into two separate sections, B2B Supplies and B2C Supplies, and HSN codes are generally selected from a portal dropdown rather than typed manually.
Table 13: Documents Issued
This table records the total count of each document type issued during the period, such as tax invoices, credit notes, and debit notes, including any that were cancelled.
How to File GSTR-1 Through Offline Tool
Businesses with a high volume of invoices often find the offline tool faster than entering each invoice manually on the portal.
Download the GSTR-1 Offline Tool
Download the GSTR-1 offline utility from the Downloads section of the GST portal. It works as an Excel-based tool where you can enter your invoice data in a structured format.
Prepare Invoice Data in the Required Format
Fill in your B2B, B2C, export, and credit/debit note data in the respective sheets of the offline tool, following the column headers exactly as provided, since the tool validates the format before generating a file.
Upload the JSON File to the GST Portal
Once your data is complete, use the tool to generate a JSON file. Log in to the GST portal, go to the GSTR-1 filing page, and upload this JSON file under the relevant upload option.
Verify Uploaded Records and File GSTR-1
After upload, check each table on the portal to confirm the records have been imported correctly, generate the summary, review it, and file as you would with manually entered data.
GSTR-1 Filing for QRMP Taxpayers
Taxpayers under the QRMP scheme follow a slightly different rhythm for reporting their sales.
Quarterly GSTR-1 Filing Process
QRMP taxpayers file one consolidated GSTR-1 for the entire quarter, covering all three months' sales, using the same tables and the same step-by-step process described above.
IFF: Invoice Filing Facility for B2B Supplies
The Invoice Furnishing Facility (IFF) lets QRMP taxpayers optionally upload B2B invoice details for the first two months of a quarter, so their buyers can claim input tax credit sooner instead of waiting until the quarterly GSTR-1 is filed. IFF only covers B2B invoices, not B2C sales.
What Happens If You Skip IFF in a Month
IFF is optional. If you do not use it for a given month, those B2B invoices simply carry forward and get reported along with the rest of the quarter's data in your quarterly GSTR-1. There is no penalty for not using IFF, as long as the full quarter's data is correctly reported in the quarterly return.
How to Revise or Amend GSTR-1 After Filing
Unlike an income-tax return, GSTR-1 cannot be revised once filed.
Can GSTR-1 Be Revised?
No. Once submitted and filed, a GSTR-1 for a period is locked and cannot be edited or re-filed. Any corrections must be made through the amendment tables in a subsequent period's GSTR-1.
How to Amend B2B Invoices in the Next GSTR-1
To correct a B2B invoice already filed, open Table 9 in a later GSTR-1, select the original invoice using its number and date, and enter the corrected details. The portal treats this as an amendment linked to the original entry.
How to Amend B2C Invoices and Credit/Debit Notes
B2C Others corrections go through Table 10 as a net adjustment, while corrections to credit or debit notes are made through the amendment section of Table 11, referencing the original note.
Correcting Wrong GSTIN, Invoice Number or Tax Amount
All three types of errors, a wrong buyer GSTIN, an incorrect invoice number, or a wrong tax amount, are corrected the same way, through the relevant amendment table in the next period's GSTR-1, not by editing the already-filed return.
Common GSTR-1 Filing Errors and How to Fix Them
Most GSTR-1 problems come from a small set of recurring mistakes.
Wrong HSN Code or Tax Rate
Error: An item is billed at the wrong GST rate because of an incorrect HSN code. Why it happens: Manual entry without a fixed product-to-HSN mapping. Fix: Maintain a master list of products with their correct HSN code and rate, and correct any wrong rate through the amendment table in the next filing.
Missing B2B Invoice Details
Error: A B2B sale is accidentally left out of Table 4. Why it happens: The invoice was missed during data entry or excluded from the sales register. Fix: Reconcile your full sales register against the GSTR-1 summary before submission, and add any missed invoice in the current period if still open, or through amendment in the next period if already filed.
Incorrect Place of Supply
Error: A sale is reported under the wrong state, affecting whether it is treated as intrastate or interstate. Why it happens: The billing address was used instead of the actual place of supply. Fix: Apply GST place-of-supply rules correctly at the time of invoicing, and correct any wrongly reported sale through the amendment table.
Duplicate Invoice Entry
Error: The same invoice appears twice in the return, inflating your reported sales. Why it happens: Manual re-entry or a repeated upload from the offline tool. Fix: Review the generated summary against your sales register count before filing, and remove the duplicate entry before submission.
GSTR-1 Not Reflecting After Submission
Error: Filed data does not immediately appear in the buyer's GSTR-2B. Why it happens: The portal typically takes some time to process and reflect newly filed data. Fix: Wait for the standard processing window, usually a day or two, before raising a grievance with the GST helpdesk.
Unable to File Due to Pending Previous Returns
Error: The portal blocks filing of the current GSTR-1. Why it happens: An earlier period's GSTR-3B or GSTR-1 has not been filed, since the portal enforces sequential filing. Fix: File all pending earlier returns first, then proceed with the current period's GSTR-1.
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GSTR-1 Filing Checklist Before Submission
- Reconcile your sales register against the GSTR-1 summary generated on the portal.
- Verify every buyer's GSTIN entered in B2B invoices.
- Check that HSN codes and GST rates match your product master.
- Confirm taxable value and tax breakup (CGST, SGST, IGST) for each table.
- Review all credit and debit notes issued during the period.
- Preview the final summary PDF before clicking Submit.
- Download and save the filing acknowledgement after successful submission.
For a broader review covering e-invoicing and reconciliation, refer to our GST compliance checklist.
FAQs on Filing GSTR-1 Online
Can I file GSTR-1 without a CA?
Yes. Any authorised person in the business, such as the proprietor, a partner, or an employee with portal access, can file GSTR-1 directly on the GST portal without involving a CA, though professional help is useful for larger or complex filings.
Can I edit GSTR-1 after filing?
No. Once filed, GSTR-1 for that period cannot be edited. Corrections are made through the amendment tables in a later period's GSTR-1.
What is the difference between GSTR-1 and GSTR-3B?
GSTR-1 reports the details of your sales, invoice by invoice or in summary form, while GSTR-3B is the summary return where you declare your total tax liability and actually pay the tax after adjusting input tax credit.
Is GSTR-1 mandatory for nil sales?
Yes. Even if there were no sales during the period, a nil GSTR-1 must still be filed to stay compliant and to avoid late fees.
Can I file GSTR-1 after the due date?
Yes, but late filing attracts a late fee per day of delay, and it can also delay your buyers' ability to claim input tax credit on your invoices.
How do I know my GSTR-1 has been filed successfully?
After filing, the portal generates an Acknowledgement Reference Number (ARN) and the return status changes to “Filed” on your Returns Dashboard. You can download the filed return and acknowledgement from the same dashboard.
For a detailed comparison, read our GSTR-1 vs GSTR-3B guide
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