Turn your sales register (Excel or CSV) into a GSTR-1 JSON file with B2B, B2C large, B2C small, HSN and document summary tables, ready to import on the GST portal.
Runs in your browserNothing uploaded or storedRules with cited sources
! Needs reviewLast verified:
1Your details
2Sales invoices
Drop your sales register (Excel or CSV)
Columns we look for: invoice no, date, buyer GSTIN, place of supply, HSN, qty, taxable value, rate. Extra columns are ignored.
Invoice no.
Date
Buyer GSTIN (blank = B2C)
Place of supply
HSN/SAC
Qty
Taxable value
Rate %
3Check and download
Import the JSON into the GST offline tool or upload it under Returns › GSTR-1 › Prepare offline on gst.gov.in. The portal validates it again; fix anything it rejects there. We never file for you.
This tool is for understanding and preparation only. Results are estimates based on the assumptions shown. File on the official channels.
How it works
Enter your GSTIN and the return month.
Drop your sales register, or type the invoices in. Each line is one invoice at one rate. Lines with the same invoice number are merged.
We sort each line:
B2B (Table 4): the buyer has a GSTIN.
B2C large (Table 5): no buyer GSTIN, inter-State, and the invoice is over ₹1,00,000.
B2C small (Table 7): everything else without a GSTIN, summed by place of supply and rate.
Tax is split into IGST when the place of supply is a different State from your GSTIN, and into CGST and SGST halves otherwise.
HSN summary (Table 12) is grouped by HSN, rate and unit, separately for B2B and B2C. Document summary (Table 13) uses the first and last invoice numbers.
Things to know
Needs review: the JSON follows the field names used by the GSTN offline tool. GSTN changes the schema from time to time. The portal is the final check; if it rejects the file, fix the data and rebuild.
Credit and debit notes, exports, nil-rated supplies and amendments are not covered yet. Add them on the portal.
Cess is not read from the import. Add cess on the portal if it applies.
Your data stays in your browser. We do not upload, store or file anything.