What every GST tax invoice must have (Rule 46)
Rule 46 of the CGST Rules lists the fields a tax invoice must carry for it to be valid — invoice number and date, the supplier’s and recipient’s name/address/GSTIN, HSN or SAC code for each item, description, quantity and unit, taxable value, applicable GST rate, the amount of CGST/SGST or IGST charged, and the signature of the supplier or their authorised representative. This tool generates a PDF with all of these fields filled in from what you enter above.
CGST + SGST vs IGST — how it’s decided
GST splits into CGST + SGST for an intra-state supply (seller and buyer in the same state) and IGST for an inter-state supply (different states). The state is read from the first two digits of the GSTIN — for a B2C sale without a buyer GSTIN, the "place of supply" state you select stands in for the buyer’s state. If the two state codes match, the GST rate splits evenly into CGST and SGST; if they differ, the full rate is charged as IGST. A few example state codes:
| Code | State |
|---|---|
| 07 | Delhi |
| 09 | Uttar Pradesh |
| 24 | Gujarat |
| 27 | Maharashtra |
| 29 | Karnataka |
| 33 | Tamil Nadu |
| 36 | Telangana |
| 19 | West Bengal |
When to issue a GST invoice
For a supply of goods, the invoice should generally be issued at or before delivery/removal of the goods. For services, you get more room — an invoice must be issued within 30 days of providing the service (45 days for banks/NBFCs). Issuing it late doesn’t change the tax due, but it can create mismatches when the buyer tries to claim input tax credit, so it’s best to invoice promptly.
HSN/SAC digit requirements by turnover
The number of digits required in your HSN/SAC code depends on your aggregate annual turnover — broadly, a 4-digit code is enough up to ₹5 crore turnover, and a 6-digit code is required above that (with further granularity for specified goods). // VERIFY — these thresholds are notified periodically by CBIC, so double-check the current requirement for your turnover slab before relying on it for compliance.
Everything stays in your browser
All calculations and the PDF itself are generated client-side in JavaScript — nothing you type here, including GSTINs or invoice amounts, is uploaded to any server.