Short answer: A GST tax invoice must show the supplier's name, address and GSTIN, a unique serial number (up to 16 characters, one series per financial year), the date, the buyer's name, address and GSTIN (if registered), HSN or SAC code, description, quantity, taxable value, GST rate and amount split into CGST and SGST or IGST, place of supply, whether tax is on reverse charge, and the supplier's signature. These fields come from rule 46 of the CGST Rules, 2017.
Mandatory fields under rule 46
| Field | What to write |
|---|---|
| Supplier | Name, address and GSTIN |
| Invoice number | Consecutive serial number, up to 16 characters (letters, numbers, “-” and “/”), unique for the financial year |
| Date of issue | The invoice date |
| Buyer | Name, address and GSTIN if registered. For an unregistered buyer, name and address and the delivery address with state name when the value is ₹50,000 or more |
| HSN / SAC | Code of the goods or services (number of digits depends on turnover: see the HSN guide) |
| Description, quantity, unit | What is sold and how much |
| Values | Total value and taxable value after discount |
| Tax | Rate and amount of CGST and SGST/UTGST, or IGST, and cess if any |
| Place of supply | State name and code, needed for inter-state supplies |
| Delivery address | If different from the place of supply |
| Reverse charge | Whether tax is payable on reverse charge |
| Signature | Signature or digital signature of the supplier or authorised person |
CGST + SGST or IGST?
If the supplier's state and the place of supply are the same, the GST is split equally into CGST and SGST (UTGST in a union territory without a legislature). If they are different, the whole GST is IGST.
Example: a Delhi trader sells goods worth ₹10,000 at 18%.
| Buyer in | CGST | SGST | IGST | Invoice total |
|---|---|---|---|---|
| Delhi | ₹900 | ₹900 | – | ₹11,800 |
| Haryana | – | – | ₹1,800 | ₹11,800 |
How many copies and when to issue
- Goods: three copies: original for the buyer, duplicate for the transporter, triplicate for the supplier. Issue it before or at the time the goods are removed or delivered.
- Services: two copies: original for the buyer, duplicate for the supplier. Issue it within 30 days of the supply (45 days for banks and NBFCs).
Bill of supply instead of tax invoice
A composition taxpayer, or a person supplying only exempt goods or services, issues a bill of supply without tax. A composition dealer must write “composition taxable person, not eligible to collect tax on supplies” on it.
When e-invoicing applies
A business whose aggregate turnover in any financial year from 2017-18 has crossed ₹5 crore must report B2B invoices on the e-invoice portal (IRP) and print the IRN and QR code on the invoice. Our bill maker makes the invoice PDF; it does not create the IRN, so such businesses must also report the invoice on the IRP.
Frequently asked questions
Can I make a GST invoice by hand or in Excel?
Yes, if it has every field required by rule 46. Software only helps you avoid missing fields and calculation mistakes. Businesses covered by e-invoicing must still report B2B invoices on the IRP.
Can the invoice number restart every year?
Yes. The serial number must be unique within a financial year, so most businesses start a new series on 1 April, for example 2026-27/001.
Is a signature compulsory?
Rule 46 asks for the signature or digital signature of the supplier or an authorised person. An e-invoice with IRN does not need a separate digital signature.
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Official sources
Rules on this page come from these official government sources. Check them for the latest position.
More guides
GSTR-1 vs GSTR-3B
What each return contains, due dates for monthly and QRMP filers, late fee and how they link.
Credit note and debit note in GST
When to issue each (section 34), the time limit, the fields and how to report them in GSTR-1.
HSN code rules
How many HSN digits you must write by turnover, SAC for services and the GSTR-1 HSN summary.
Last updated: 7 November 2026. Published by S Jha Legal Sansar & Associates. Rules as applicable for FY 2026-27; laws change, so check the official source before you act. Editorial policy · Disclaimer