GSTR-1 is a statement filed by a GST-registered dealer to report sales, other outward supplies and related information to the GST department. Correct reporting helps registered customers reconcile their purchases and claim eligible input tax credit.
Before filing, reconcile your invoices, credit notes, debit notes, taxable service advances and other applicable details with your accounting records.
This guide explains who should file GSTR-1, which tables to use, how IFF differs from GSTR-1, and how to correct mistakes.
What is GSTR-1?
GSTR-1 is the statement in which a regular GST-registered dealer reports outward supplies for a month or quarter.
It includes taxable sales, exports, supplies to SEZ units, nil-rated and exempt supplies, credit and debit notes, and other applicable details.
GSTR-1 reports transactions, while GSTR-3B declares the summary tax liability, eligible input tax credit and payment of tax.
For a regular dealer, filing GSTR-1 alone does not complete the normal return filing process for that period. Start by reporting outward supplies in GSTR-1, then complete the applicable GSTR-3B after reconciling the liability and input tax credit.
Example: A wholesaler sells goods worth ₹1,00,000 plus GST at 18%, amounting to ₹18,000, to a registered retailer. The wholesaler reports the invoice in GSTR-1. The retailer checks the invoice in GSTR-2B and claims the eligible ₹18,000 credit, subject to the applicable conditions.
Why should you check the customer’s GSTIN carefully?
An incorrect GSTIN can prevent the invoice from appearing against the correct customer’s registration.
A typing mistake may still pass portal validation if the entered GSTIN belongs to another registered dealer. The invoice may then appear in that dealer’s GST statements instead.
However, its appearance does not give that dealer a valid entitlement to claim credit. Credit is also not automatically added to the electronic credit ledger merely because an invoice appears in GSTR-2B.
Check both the GSTIN and the recipient name before filing.
Who should file GSTR-1?
Regular GST-registered dealers generally file GSTR-1:
- Monthly, where monthly filing applies.
- Quarterly, where an eligible dealer has opted for the QRMP scheme.
Casual taxable persons also generally file GSTR-1.
Composition dealers do not file GSTR-1 for their composition returns. Other registration categories, such as input service distributors, non-resident taxable persons and persons registered only for GST TDS or TCS, have different reporting requirements.
Should you file GSTR-1 when there are no sales?
Yes. A regular dealer generally needs to file the applicable statement even when there is no business activity.
However, no sales does not automatically mean that a Nil GSTR-1 is appropriate. Check whether there are:
- Other outward supplies, including exempt or zero-rated supplies.
- Credit or debit notes to report.
- Corrections to transactions reported earlier.
- Taxable service advances to report or adjust.
- Applicable document details, including serial ranges and cancellations, to report.
If any details need reporting, check the applicable tables before selecting Nil.
GSTR-1 due dates and the difference between GSTR-1 and IFF
The normal due dates are:
| Filing arrangement | Statement | Normal due date |
|---|---|---|
| Monthly filing | GSTR-1 | 11th of the following month |
| Quarterly filing under QRMP | GSTR-1 | 13th of the month following the quarter |
| QRMP—first and second months of the quarter | Optional IFF | 13th of the following month |
The government may extend a filing deadline through a notification, including for natural calamities, portal difficulties or other circumstances. An extension may apply nationally or only to specified taxpayers, locations or periods.
Check whether an extension applies to your return before relying on a revised date.
How does IFF differ from GSTR-1?
The Invoice Furnishing Facility, or IFF, allows a QRMP dealer to report eligible invoices and notes relating to registered customers during the first two months of a quarter.
This helps customers receive their purchase details for the relevant monthly credit cycle without waiting for the quarterly GSTR-1.
| Point | GSTR-1 | IFF |
|---|---|---|
| Who uses it? | Monthly and quarterly regular dealers | Dealers who have opted for QRMP |
| Is it compulsory? | Generally required for each applicable period | Optional |
| What does it cover? | Applicable outward supply details for the month or quarter | Eligible B2B invoices, related credit/debit notes and permitted amendments |
| When is it used under QRMP? | At the end of the quarter | During the first two months |
| Monthly limit | No equivalent IFF limit | Eligible supplies up to ₹50 lakh per month |
| Treatment of filed IFF records | Do not report them again as fresh records | Keep them in the quarterly reconciliation |
Example: A dealer files quarterly returns for April–June 2026. Some registered customers want their April and May invoices reported promptly so they can claim eligible credit for those periods.
The dealer can furnish those eligible invoices through April and May IFF, then report the remaining applicable details in quarterly GSTR-1.
Invoices already furnished through IFF should not be uploaded again as fresh invoices.
A useful reconciliation is:
Records furnished through April and May IFF + remaining records reported in quarterly GSTR-1 = the quarter’s complete applicable reporting.
Although quarterly GSTR-1 is accessed under the third month on the portal, it relates to the entire quarter. IFF is an optional facility for reporting selected eligible details earlier; it does not replace quarterly GSTR-1 or GSTR-3B.
What are the main tables in GSTR-1?
You do not need to fill every table. Select the tables applicable to your transactions.
Sales and other outward supplies
| Table | What it broadly covers | Practical check |
|---|---|---|
| 4A, 4B, 6B and 6C | B2B invoices, SEZ supplies and deemed exports | Verify customer GSTIN and the correct supply category |
| 5 | B2C Large invoices | Check whether the sale is interstate and total invoice value exceeds ₹1 lakh |
| 6A | Exports | Check invoice details and export-related particulars |
| 7 | B2C Others | Report applicable net taxable supplies separately by place of supply and tax rate |
| 8 | Nil-rated, exempt and non-GST outward supplies | Keep these categories separate |
B2B means supplies to registered recipients. A purchaser may run a business but remain unregistered. Such a purchase does not become B2B merely because it is a business purchase.
For B2C Large reporting, the relevant threshold is the total invoice value, rather than taxable value alone.
Example: A Tamil Nadu dealer makes an interstate sale to an unregistered customer, with Karnataka as the place of supply. The taxable value is ₹90,000 and GST is ₹16,200. The total invoice value is ₹1,06,200, exceeding the ₹1 lakh threshold for B2C Large reporting.
An intrastate sale does not become B2C Large merely because its invoice value exceeds ₹1 lakh.
Determine interstate or intrastate treatment using the supplier’s location and the applicable place of supply, rather than simply the customer’s address.
Sales returns, credit notes and debit notes
Table 9B covers applicable credit and debit notes, with separate options for registered and unregistered recipients.
A sales return may lead to a credit note. An increase in the taxable value or tax charged may require a debit note.
Example: A registered customer returns part of an earlier purchase. Report the applicable credit note under the registered-recipient category and reconcile it with the GST accounting records.
Do not assume every accounting credit note permits a reduction in GST liability. Check the nature of the adjustment and the conditions for reducing tax.
B2C Others reporting generally reflects applicable net supplies. Avoid reducing the same sale twice through both the sales summary and a separate adjustment.
Advances received and adjustment of advances
| Table | Purpose |
|---|---|
| 11A | Report applicable tax liability on advances received where an invoice has not been issued in the same period |
| 11B | Adjust advances taxed earlier against supplies invoiced in the current period |
These tables are particularly relevant to taxable service advances. Ordinary advances for supplies of goods by regular dealers generally have different treatment.
Example: A management consultant filing monthly receives an advance in October 2026 for taxable services to be provided in December 2026. No invoice is issued in October.
The applicable advance is reported in October GSTR-1 through Table 11A. When the invoice is issued in December, report the invoice and adjust the advance through Table 11B so the same amount is not taxed twice.
Keep an advance register showing the receipt date, customer, place of supply, taxable amount, tax paid and later invoice adjustment.
HSN-wise summary of outward supplies
Table 12 contains the HSN-wise summary of outward supplies. For services, the relevant classification is the service accounting code, or SAC.
The required code length generally depends on the preceding financial year’s aggregate turnover:
| Preceding financial year’s aggregate turnover | Code length generally required |
|---|---|
| Up to ₹5 crore | Four digits |
| Above ₹5 crore | Six digits |
The portal provides separate B2B and B2C reporting in the HSN summary.
Check the sales category, HSN/SAC classification, tax rate, taxable value, tax amounts and, where applicable, quantity and unit of measurement.
Practical point: Do not choose a code merely because its description appears similar. Match it with the actual goods or services supplied, and reconcile the summary with the transaction tables.
Documents issued
Table 13 reports document series and counts. It includes sales invoices, credit and debit notes, relevant vouchers and different categories of delivery challans.
The main fields include:
- Serial number from and to.
- Total number of documents.
- Cancelled documents.
- Net documents issued.
Example: Your invoice series runs from INV001 to INV100, and two invoices were cancelled.
| Particular | Count |
|---|---|
| Total documents | 100 |
| Cancelled documents | 2 |
| Net issued | 98 |
If you use separate series for branches, sales channels or document types, reconcile each applicable series separately.
A cancelled invoice number should remain traceable in your records.
Supplies made through e-commerce operators
| Table | Who reports it? | Broad purpose |
|---|---|---|
| 14 | Supplier | Applicable supplies made through e-commerce operators |
| 15 | E-commerce operator | Applicable supplies for which the operator pays GST under the specified mechanism |
Table 14 distinguishes supplies where the operator collects TCS from supplies where the operator is liable to pay GST.
Practical point: Selling through an online platform does not automatically mean the platform pays GST on your sale. Identify the applicable arrangement before reporting it.
Reconcile platform statements with invoices, sales returns and credit notes. The net bank settlement may include deductions for platform fees, shipping charges, return-related charges, TCS and other adjustments. Do not treat that settlement amount as the sales value without reconciling these items.
How to file GSTR-1 on the GST portal
Step 1: Prepare and reconcile your records
Collect the sales register, invoices, credit/debit notes, export details, applicable advances received, invoices issued against those advances, HSN summary and document counts.
Where relevant, also collect e-invoice, e-way bill and e-commerce platform reports.
Check for missing invoices, duplicate records and differences between your accounting records and the return data.
For QRMP dealers, reconcile invoices furnished through IFF with the quarter’s accounting records and the remaining details to be reported in GSTR-1.
Maintain a consolidated filing workbook, such as an Excel file, or an equivalent report from your accounting software. It should bring together the supporting details and summaries for each filing period.
This record helps with later reconciliations, annual GST returns where applicable, and audit preparation.
Step 2: Open the return for the correct period
After logging in, follow:
Services → Returns → Returns Dashboard
Select the Financial Year, Quarter and Period, then click Search.
On the GSTR-1 card, choose Prepare Online.
Check the tax period before entering or uploading anything. Monthly filers also select a quarter on the dashboard before selecting the relevant month.
Step 3: Enter or upload the applicable details
Open the relevant table under Add Record Details.
For a B2B invoice, check:
- Recipient GSTIN/UIN and the displayed recipient name.
- Invoice number and date.
- Total invoice value.
- Place of supply.
- Applicable supply category and tax details.
The total invoice value and taxable value serve different purposes. Do not enter the tax-inclusive total as taxable value.
Where e-invoices are populated automatically, reconcile them before adding records manually to avoid duplication.
Step 4: Review errors and complete supporting tables
Resolve rejected or invalid records. Then complete the applicable HSN summary, document counts and other relevant tables.
GST portal validation helps identify certain errors, such as an invalid GSTIN or duplicate records within the relevant checks. It does not establish that every invoice has been included or that the tax treatment is correct.
An accepted record still needs to agree with your invoice and accounting records.
Step 5: Generate and review the summary
Click Generate Summary and allow the portal to process the request.
Once available, open the summary and reconcile it with your sales register and other supporting records. Check invoice counts, taxable values, tax amounts, credit/debit notes, advances and amendments. If you maintain a consolidated GST return filing Excel workbook, ensure that all these details match its summary before proceeding to file.
Use Reset only if you intend to delete saved details across all tables. To remove a particular saved entry, open the relevant table and use the available delete option for that record.
Step 6: Complete filing and retain the acknowledgement
After reconciling the return with your consolidated workbook or accounting reports, complete the declaration and authentication using the applicable filing method.
Confirm that the status changes to Filed and retain the acknowledgement.
Saved, summary generated and Ready to File are intermediate stages. They do not mean the return has been filed.
How can you correct GSTR-1?
A filed GSTR-1 cannot simply be reopened and replaced as a revised return.
The correction method depends on when you find the error.
| Timing of mistake identification | Usual correction route |
|---|---|
| Before filing GSTR-1 | Edit the draft details |
| After filing GSTR-1, but before filing the same period’s GSTR-3B | Use GSTR-1A where the correction is permitted |
| After filing that period’s GSTR-3B | Report the permitted correction through a subsequent GSTR-1 |
The portal has a separate Amend Record Details group for amendments to earlier reported transactions.
Use the appropriate amendment category rather than reporting the same invoice again as a fresh sale. A genuinely omitted invoice requires the appropriate addition rather than an amendment to a record that was never reported.
What is the time limit for corrections?
Corrections for a financial year generally need to be made by 30 November following that financial year, or before filing the relevant annual return, whichever is earlier.
Example: For financial year 2025–26, the general deadline is 30 November 2026. If the relevant GST annual return is filed on 25 November 2026, the corrections must be completed before filing that annual return on 25 November.
Check separately whether the correction also affects tax payment, interest or the customer’s input tax credit.
What is GSTR-1A, and when should you use it?
GSTR-1A is an optional facility to add missed outward supply details or correct permitted details for the current tax period after GSTR-1 has been filed.
It becomes available after the later of:
- The GSTR-1 due date.
- The actual date on which GSTR-1 is filed.
It must be filed before GSTR-3B for the same tax period and can be filed only once for that period.
Example: A sales invoice was missed
A monthly dealer files GSTR-1 and later discovers that one sales invoice was omitted. GSTR-3B has not yet been filed.
The dealer can report the missed invoice through GSTR-1A, where applicable, and check the resulting liability before filing GSTR-3B.
Example: The taxable value was incorrect
An invoice was reported with a taxable value of ₹10,000 instead of ₹1,00,000.
If the same period’s GSTR-3B has not been filed, the dealer can use GSTR-1A for the permitted correction rather than carrying the incorrect liability into GSTR-3B.
Important limits of GSTR-1A
- GSTR-1A relates to the current tax period. Earlier-period corrections can be made through a subsequent GSTR-1, subject to the correction deadline.
- The recipient GSTIN cannot be amended through GSTR-1A.
- Permitted corrections to IFF details from the first two months can be addressed through the quarter’s GSTR-1A.
- Saved GSTR-1A details must be appropriately filed or cleared before proceeding with GSTR-3B.
- Details furnished through GSTR-1A will reflect in the recipient’s GSTR-2B for the next tax period—normally the following month for monthly recipients.
Practical point: Inform an affected customer about the correction. Do not promise that filing GSTR-1A will place the invoice in the customer’s current-period GSTR-2B.
How can e-way bill data help with GSTR-1?
E-way bill data can help identify goods invoices that may be missing from the sales register or return preparation.
The portal provides Import EWB Data in supported areas, including the B2B table.
Compare available records with your invoices before importing or relying on them.
| Check | Why it matters |
|---|---|
| Document type | A movement may relate to a delivery challan rather than a sale |
| Invoice number and date | Identify missing or duplicate records |
| Recipient GSTIN | Match the correct customer registration |
| Values and tax details | Reconcile movement data with the invoice |
| Cancellation status | Avoid treating cancelled records as valid supplies |
| Existing return records | Avoid duplicating manually entered or auto-populated invoices |
Example: Goods sent to a job worker may have an e-way bill. That movement does not, by itself, establish a taxable sale to the job worker.
Likewise, many service transactions will not appear in e-way bill data.
Treat the report as a reconciliation aid, not a complete replacement for your sales records.
What are the late fees, interest and penalties for GSTR-1?
Late fees
The normal late fee per day (CGST + SGST) is:
| Return | Late fee per day |
|---|---|
| Nil GSTR-1 | ₹20 |
| Other GSTR-1 | ₹50 |
The normal maximum late fee limits (CGST + SGST) are:
| Category | Maximum late fee |
|---|---|
| Nil GSTR-1 | ₹500 |
| Other returns—preceding financial year’s turnover up to ₹1.5 crore | ₹2,000 |
| Other returns—preceding financial year’s turnover above ₹1.5 crore and up to ₹5 crore | ₹5,000 |
| Other returns—preceding financial year’s turnover above ₹5 crore | ₹10,000 |
When the due date is officially extended for the applicable return and tax period, late fees are calculated from the day after the extended due date.
Interest
Late filing of GSTR-1 alone does not automatically attract interest.
Interest on delayed tax payment arises when tax is paid after its applicable due date. This may concern the current period’s liability or earlier-period invoices reported later, if the tax on those invoices was not paid on time.
Reporting an earlier-period invoice in the current return does not, by itself, create interest if the related tax was already paid on time.
Penalties
Late fees and penalties are different. Additional consequences depend on the facts, such as incorrect reporting or failure to comply.
Do not assume that every late GSTR-1 attracts the same additional penalty.
Frequently asked questions
Can I file GSTR-3B without filing GSTR-1?
For regular taxpayers, GSTR-3B can be filed only after GSTR-1 has been filed for the same tax period.
Should I report IFF invoices again in quarterly GSTR-1?
Do not duplicate invoices already furnished through IFF. Reconcile the quarterly sales register with IFF records and report the remaining applicable details.
Is an added invoice record correct if the GST portal accepts it?
Not necessarily. The GST portal may accept an invoice with a valid recipient GSTIN and tax calculated at an available rate even when the recipient, taxable value or selected tax rate is incorrect.
Portal acceptance confirms that the record has passed the applicable system checks; it does not confirm that the details match the actual transaction. Check the record against the original invoice and accounting records.
Is generating the summary enough?
No. Review the summary, complete authentication and confirm that the return status is Filed.
Can GSTR-1A correct every error?
No. It has timing and field restrictions. For example, recipient GSTIN cannot be amended through GSTR-1A.
Does filing GSTR-1 guarantee the customer’s input tax credit?
No. Correct supplier reporting supports credit availability, but the customer must also meet the applicable eligibility conditions and check the relevant GST statements.
Need help with GSTR-1 filing?
Our GST return filing services in Chennai can help you reconcile sales records, review the applicable tables and address reporting differences before filing.
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Written by R. Parasuraman
20 years of expertise in Tax and Business Compliance