GST returns
How to file GSTR-1: a simple step-by-step guide
GSTR-1 is the return where you report your sales. If you are a regular GST-registered business, you file it every month or every quarter. Here is what it is, when it is due and how to file it without the usual headache.
What is GSTR-1?
GSTR-1 is a return that lists the outward supplies (sales) you made in a period: your B2B invoices, B2C sales, credit and debit notes, exports and advances. The government uses it to pass on input tax credit to your buyers, so the figures have to match your invoices.
Who has to file it?
Almost every regular GST-registered business files GSTR-1. Businesses under the composition scheme do not; they file different returns. If you are registered as a normal taxpayer, GSTR-1 applies to you even in a month with no sales, when you file a nil return.
Monthly or quarterly? (QRMP and IFF)
If your turnover is up to ₹5 crore, you can opt for the QRMP scheme and file GSTR-1 once a quarter. If you are above that, or you have not opted into QRMP, you file monthly.
- Monthly filers: GSTR-1 is generally due by the 11th of the following month.
- Quarterly (QRMP) filers: GSTR-1 is generally due by the 13th of the month after the quarter.
- IFF (Invoice Furnishing Facility): QRMP filers can optionally upload B2B invoices for the first two months of the quarter by the 13th, so buyers get their credit sooner.
What you need before you start
- Your GST portal login (GSTIN and password).
- All sales invoices for the period, with correct GSTINs, HSN codes and tax amounts.
- Any credit or debit notes issued in the period.
- A clean summary of B2C sales.
How to file GSTR-1, step by step
- Log in to the GST portal and go to Returns Dashboard.
- Choose the financial year and the return period (month or quarter).
- Open GSTR-1. You can enter invoices by hand, or upload a JSON file prepared by your billing software.
- If you use a billing app, generate the GSTR-1 JSON for the period and upload it; the invoices fill in automatically.
- Check the summary: total taxable value, CGST, SGST/UTGST, IGST and cess.
- Fix any errors the portal flags, then submit and file with DSC or EVC.
FinBill prepares your GSTR-1 as a ready-to-upload JSON file (monthly or quarterly with IFF), plus Excel and PDF copies, straight from the bills you already made. You upload the JSON on the portal, check the figures and file.
Common mistakes to avoid
- Wrong or missing buyer GSTINs, which block their input credit.
- Mismatched HSN codes or tax rates on items.
- Forgetting credit and debit notes for returns and adjustments.
- Missing the due date, which attracts a late fee and interest.
GST rules and due dates change from time to time. Use this as a plain-language starting point and confirm the current rules with your CA or on the official GST portal before you file.
Frequently asked questions
Is GSTR-1 the same as GSTR-3B?+
No. GSTR-1 reports your sales invoice by invoice. GSTR-3B is a monthly summary of sales, input credit and the tax you pay. You usually file both.
Do I file GSTR-1 if I had no sales?+
Yes. You file a nil GSTR-1 for the period. On the portal you can file a nil return in a few taps.
Can a billing app file GSTR-1 for me?+
An app prepares the GSTR-1 data as a JSON file you upload on the GST portal. The actual filing and signing happens on the portal.