How to file GSTR-1 straight from your sales records
How to file GSTR-1 from your own sales data: which bills go in which table, how to check totals before you file, and how to correct a mistake afterwards.
GSTR-1 is your sales return: every bill you raised in the period, sorted into the tables the GST portal expects. If your billing already records the buyer's GSTIN, the place of supply, the HSN code and the tax on every bill, you do not need to type the return at all. You export the period's sales as a file the portal accepts, check a few totals against your books, upload, and file.
Last reviewed: September 2026. Return periods, due dates, table rules and the invoice-value limits that decide which table a sale goes in are set by the GST law and the portal, and they change. Confirm the current position for your business on the GST portal or with your CA.
What is GSTR-1 and why does it matter to your buyers?
GSTR-1 is the statement of outward supplies. It tells the GST system what you sold, to whom, and how much tax you charged, for each return period. It is filed monthly, or quarterly if your business is eligible for and has opted into the quarterly return scheme. Quarterly filers can pass on B2B invoices for the first two months of the quarter through the Invoice Furnishing Facility.
It matters to more people than you. Your B2B invoices in GSTR-1 are what your registered buyers see in their own input tax credit statement. If an invoice is missing or wrong in your return, your buyer's credit is held up, and they will be on the phone to you before month end.
It also feeds your own GSTR-3B: the portal pre-fills your tax liability in GSTR-3B from what you reported in GSTR-1.
Which of your sales go in which part of GSTR-1?
Every bill goes in exactly one place, and your billing data already decides which. The main tables are:
| Kind of sale | Where it goes in GSTR-1 | How it is reported |
|---|---|---|
| Bill to a registered party (has a GSTIN) | B2B | Invoice by invoice |
| Inter-state bill to an unregistered buyer above a set invoice value | B2C large | Invoice by invoice |
| All other bills to unregistered buyers | B2C others | Summary, not invoice by invoice |
| Exports | Exports | Invoice by invoice |
| Credit and debit notes to registered parties | Credit/debit notes (registered) | Note by note |
| Credit and debit notes to unregistered buyers, where required | Credit/debit notes (unregistered) | Note by note |
| Nil-rated, exempt and non-GST sales | Nil rated / exempt | Summary |
| Every item sold | HSN summary | By HSN code, split between B2B and B2C sales |
| Every invoice and note series | Documents issued | Opening and closing serial numbers, count, cancelled |
The invoice-value limit that separates "B2C large" from "B2C others" is fixed by the rules and can change, so check the current figure on the portal. The point to take away is that the split depends on facts your bill already holds: whether the buyer has a GSTIN, whether the supply is inter-state, and the invoice value.
What must your sales data hold before you can export it?
Five fields decide whether a bill lands in the right table with the right numbers. If any of them is missing or typed per bill, the export is where you will find out.
- Buyer's GSTIN, checked when the party is created, not at the counter. A wrong GSTIN sends the credit to someone else's statement.
- Place of supply, which decides CGST and SGST or IGST and whether a B2C sale is inter-state.
- HSN code and rate on the item, so the HSN summary agrees with the tax you charged. If you are unsure of a code, see how to find the right HSN code for your product.
- An unbroken invoice series, because the documents issued table reports your serial numbers and cancelled bills.
- Credit and debit notes linked to the original invoice, so the correction reports against the right bill.
These are the same particulars a GST invoice must contain. A correct invoice is most of a correct GSTR-1.
How do you file GSTR-1 from your sales records, step by step?
Seven steps, in this order.
- Close the period in your books. Make sure every bill, credit note and debit note for the period is entered, and that cancelled bills are marked cancelled rather than deleted.
- Run a sales register for the period and note three totals: taxable value, tax charged, and the number of documents issued.
- Generate the GSTR-1 file. Either your billing software produces a JSON file for the portal, or you fill the Excel template in the portal's free Returns Offline Tool, which checks the fields and generates the JSON for you.
- Log in to the GST portal and open GSTR-1 for the period from the returns dashboard. Menu names on the portal change from time to time; the returns dashboard is the place to start.
- Upload the JSON file. If the portal rejects any records, it gives you an error file you can open in the offline tool, fix, and upload again.
- Compare the portal's summary with your register. Taxable value and tax, table by table, should match the totals you noted in step 2.
- File with a DSC or an EVC. You can file with a digital signature certificate or with an electronic verification code sent to the authorised signatory's registered mobile and email.
If you issue e-invoices, your e-invoices already appear in GSTR-1 as saved records. Treat them as a starting point, not a finished return, and check them against your register like everything else.
How do you check the numbers before you file?
Tie the return back to your sales register with one simple sum: everything you sold, less notes, should equal what the tables add up to.
Say your sales register for the month shows a total taxable value of ₹8,40,000. Split by table, the export shows:
| Table | Taxable value |
|---|---|
| B2B invoices | ₹5,10,000 |
| B2C others | ₹3,05,000 |
| Exports | ₹40,000 |
| Credit notes to registered parties | less ₹15,000 |
| Net | ₹8,40,000 |
₹5,10,000 plus ₹3,05,000 plus ₹40,000 is ₹8,55,000. Less the ₹15,000 credit note, that is ₹8,40,000, which matches the register. If it had come to ₹8,32,000, you would know an ₹8,000 bill had been left out, or put in the wrong table, before the return went in, not after your buyer found it.
Run the same check on tax charged, and make sure the HSN summary adds up to the same taxable value and tax as the rest of the return.
What if you find a mistake after filing GSTR-1?
You correct it; you do not file a second GSTR-1 for the same period. How you correct it depends on timing.
- Before you file GSTR-3B for the same period, the portal offers GSTR-1A. You can use it once for a period to correct records you reported or add ones you missed, and the corrected values flow into your GSTR-3B.
- After GSTR-3B is filed, the correction goes into the amendment tables of a later GSTR-1, against the original invoice.
- If the sale itself changed, for example goods came back or a price was revised, the fix is a credit note or debit note against the original invoice, not an amendment.
Amendments and credit notes both have time limits tied to the financial year. Confirm the current limits with your CA before relying on a late correction.
Why does clean billing make GSTR-1 an export rather than a job?
Because every question GSTR-1 asks is already answered by your bills. Is the buyer registered, is the supply inter-state, what is the HSN code, what is the invoice value: if your billing records these on every bill, sorting the period into tables is something software can do in seconds, and your month-end work shrinks to checking totals.
If those answers live in someone's memory or a spreadsheet column, the return becomes a monthly re-typing exercise, and every re-typed number is a chance for your return to disagree with your bills. That is the same point at which a stock sheet stops paying its way.
FAQ
What is GSTR-1? GSTR-1 is the statement of outward supplies a registered business files on the GST portal. It lists your sales for the period: invoice by invoice for registered buyers, in summary for most sales to consumers, plus credit and debit notes, exports, an HSN-wise summary and a count of documents issued. Your buyers' input tax credit statements are built from it.
Can I upload GSTR-1 from my billing software instead of typing it? Yes. The GST portal accepts GSTR-1 data as a JSON file, either generated by the free Returns Offline Tool from an Excel sheet or produced by your billing or accounting software. You upload the file, check the summary the portal shows, and then file the return with a digital signature certificate or an electronic verification code.
What happens if I make a mistake in GSTR-1 after filing? For the same tax period, the portal offers GSTR-1A, which lets you correct or add records after filing GSTR-1 but before filing GSTR-3B for that period. Once GSTR-3B is filed, corrections go through the amendment tables of a later GSTR-1. Amendments have a time limit, so confirm it with your CA.
Do e-invoices appear in GSTR-1 automatically? Yes. Invoices and notes reported on the Invoice Registration Portal are passed to the GST system and appear in your GSTR-1 as saved records for the period matching the document date. They are not filed for you. You still review them against your own sales register, add anything missing, and file the return yourself.
Related reading: what a GST invoice must contain, whether you need to generate e-invoices and reconciling GSTR-2B with your purchase register.
If you would rather your GSTR-1 came out of the bills you already raised, see how KillStock prepares GST return workings from your documents and what it costs.