Glossary
What is a tax invoice?
The document that charges GST and gives your buyer the right to claim it back.
Updated
In short
A tax invoice is the document a GST-registered business issues for a taxable supply, with mandatory fields such as GSTINs, HSN codes and tax amounts. SimpleERP prints every invoice with these fields on a clean A4 page.
A tax invoice is the document a GST-registered business issues for a taxable supply. It must show the supplier's and, if registered, the buyer's names, addresses and GSTINs, a unique serial number of up to 16 characters, the date, HSN or SAC codes, taxable value, the rate and amount of each tax and the place of supply. A buyer needs a valid tax invoice to claim input tax credit.
Tax invoice: a worked example
Invoice INV-2026-27-0213 from Lakshmi Steel Furnitures to Ravi Stores shows each mandatory field.
| Field | On the invoice |
|---|---|
| Supplier and GSTIN | Lakshmi Steel Furnitures, 33AAACL1234A1ZG |
| Buyer and GSTIN | Ravi Stores, 33ABCPR4821K1ZN |
| Number and date | INV-2026-27-0213, 24/09/2026 |
| Place of supply | Tamil Nadu (33) |
| Line | Steel rack 4 shelf, HSN 9403, 2 × ₹4,990 |
| Taxable value | ₹9,980.00 |
| Tax | CGST 9% ₹898.20, SGST 9% ₹898.20 |
| Total | ₹11,776.00, in words |
When must a tax invoice be issued?
For goods, before or at the time of removal or delivery. For services, within 30 days of providing the service, or 45 days for banks and similar institutions. An invoice dated later than this can bring interest on tax paid late. The GST invoice format guide lists every field.
FAQ
Questions, answered
What is the difference between a tax invoice and a bill of supply?
A tax invoice charges GST and lets a registered buyer claim the tax as credit. A bill of supply charges no GST and is issued for exempt goods or by a composition dealer. The buyer cannot claim credit on a bill of supply.
Can I edit a tax invoice after I have issued it?
You should not. Once issued, a wrong invoice is corrected with a credit note, which reduces the value or tax, or a debit note, which increases it, both referring to the original. This keeps your GSTR-1 and your buyer's credit in agreement.
Does a tax invoice need a signature?
A tax invoice needs a signature or digital signature of the supplier or an authorised person. Invoices registered as e-invoices are exempt from the signature requirement because the QR code and IRN serve as authentication.
How many copies of a tax invoice do I need for goods?
Three: the original for the buyer, a duplicate for the transporter and a triplicate for your records. For services, two copies are enough. Many businesses print one and share the PDF, which is accepted in practice.
Related
Keep reading
GST invoice format
A GST tax invoice format with every rule 46 field, as a free Excel, Word and PDF download.
Read moreBill of supply
The document issued instead of a tax invoice when no GST is charged.
Read moreGST invoice format
The fields a GST tax invoice must carry, how place of supply picks CGST and SGST or IGST, HSN and SAC codes, and a worked invoice.
Read more
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