How to file GSTR-1

What is GSTR-1?

GSTR-1 is the monthly or quarterly return that records all outward supplies (sales) made by a GST-registered taxpayer. It contains invoice-level details for B2B supplies, summary figures for B2C supplies, debit and credit notes, advance receipts and an HSN-wise summary. GSTR-1 data is the primary source for auto-populating GSTR-2B (ITC statement) for your buyers — so accurate and timely filing protects your customers' ITC claims.

Who files GSTR-1?

All regular GST-registered taxpayers must file GSTR-1. Composition scheme taxpayers, ISDs and persons under specific notifications are exempt. You must file even if you have no outward supplies in a period (nil GSTR-1).

Monthly vs QRMP (quarterly) filing

Taxpayers with aggregate annual turnover up to ₹5 crore can opt for the QRMP (Quarterly Return Monthly Payment) scheme. Under QRMP:

• GSTR-1 is filed once per quarter (due on the 13th of the month after quarter-end).
• An optional Invoice Furnishing Facility (IFF) is available for months 1 and 2 of the quarter (due 13th) to upload B2B invoices so buyers can get timely ITC.
• Tax is paid monthly using PMT-06 challan (35% of the previous quarter's tax or actual computation).

Taxpayers with turnover above ₹5 crore must file GSTR-1 monthly, due on the 11th of the following month.

GSTR-1 due dates

Key tables in GSTR-1

Table 4 — B2B taxable supplies

Every invoice issued to a GST-registered business buyer must be reported individually in Table 4. Required fields for each invoice: invoice number and date, buyer's GSTIN, invoice value, taxable value, GST rate, and the CGST/SGST/IGST breakdown. The place of supply determines whether CGST+SGST (intra-state) or IGST (inter-state) applies.

Table 5 — B2C Large (inter-state, above ₹2.5 lakh)

Inter-state invoices issued to unregistered buyers where the invoice value exceeds ₹2.5 lakh must be reported invoice-wise in Table 5. State of the buyer and the GST rate are mandatory.

Table 7 — B2C Small (consolidated)

All other B2C invoices (intra-state of any value, and inter-state below ₹2.5 lakh) are reported as a consolidated summary in Table 7 — state-wise and rate-wise totals, not individual invoices. This reduces compliance burden for high-volume retail businesses.

Table 9A, 9B — Amendments and credit/debit notes

If you issued a credit note (for sales returns or price reductions) or a debit note (for additional charges), report it in Table 9B. Amendments to previously filed invoices go in Tables 9A (B2B amendments) or 9C (B2C Large amendments). The original invoice details and the revised details must both be entered.

Table 11 — Advances received

Advances received for future supplies on which GST is payable must be reported in Table 11A. When the final invoice is issued and the advance is adjusted, the adjustment goes in Table 11B. Many small businesses do not collect advances — if this does not apply to you, leave it blank.

Table 12 — HSN-wise summary

Table 12 requires a summary of supplies by HSN (Harmonised System of Nomenclature) or SAC (Services Accounting Code). The level of detail required depends on turnover:

For each HSN, enter: description, UOM, total quantity, total taxable value, and GST amount (IGST/CGST/SGST). Use the HSN code finder to look up the correct code and rate for any product or service.

Step-by-step: filing GSTR-1 on the portal

1. Log in to gst.gov.in. Go to Services → Returns → Returns Dashboard. Select the year and period, then click Prepare Online under GSTR-1.
2. Add B2B invoices in Table 4 by clicking Add Details. Enter the buyer's GSTIN, invoice number, date, invoice value, taxable value, and GST rate. Save each invoice.
3. Add B2C Large invoices in Table 5 for inter-state invoices above ₹2.5 lakh to unregistered buyers.
4. Enter consolidated B2C Small figures in Table 7 for all remaining B2C invoices, grouped by state and rate.
5. Add any credit notes or debit notes in Table 9B. Enter the original invoice reference, the note number and date, and the revised taxable value and GST.
6. Fill Table 12 with the HSN-wise summary. Most billing software can export this; BillRaja generates it automatically.
7. Click Preview to review, then Submit to freeze the data. Finally, click File GSTR-1 and authenticate with DSC or EVC.

Reconciling GSTR-1 with GSTR-3B

After filing GSTR-1, the tax on outward supplies declared there must match what you declare in GSTR-3B Table 3.1(a). A mismatch between the two is a common trigger for GST department scrutiny notices. Before filing GSTR-3B, always verify:

• Total taxable value in GSTR-1 Table 4+5+7 ≈ Table 3.1(a) taxable value in GSTR-3B
• Total IGST in GSTR-1 ≈ IGST declared in GSTR-3B
• Total CGST + SGST in GSTR-1 ≈ CGST + SGST in GSTR-3B

Small differences can arise from rounding, but systematic gaps must be investigated and corrected by amending GSTR-1 or adjusting the next GSTR-3B.

How BillRaja structures your GSTR-1 data

Every invoice created in BillRaja records the buyer's GSTIN (if registered), the HSN code for each line item, the applicable GST rate and the CGST/SGST/IGST split — the exact fields GSTR-1 requires. The monthly reports show B2B and B2C totals separately, and the HSN summary is pre-calculated. For e-invoicing-enabled businesses, BillRaja also supports the IRN flow — see the e-invoicing guide for details.