A clear invoice protects you and your customer. It is the document that supports tax claims, payments and records. This guide covers the details a GST tax invoice normally includes in India. Rules and thresholds change, so confirm current requirements with the official GST portal or your accountant.
The usual details
- Supplier details: business name, address and GSTIN.
- Invoice number and date: a unique, sequential number, with no gaps or repeats within a financial year.
- Customer details: name and address, plus GSTIN if the customer is registered.
- Goods or services: description, HSN (goods) or SAC (services) code, quantity and unit.
- Value and tax: taxable value, GST rate, and the tax amount split into CGST and SGST, or IGST.
- Place of supply and the invoice total, often also in words.
- Signature or digital signature of the supplier.
CGST/SGST or IGST?
Broadly, when the supplier and the place of supply are in the same state, the tax is split into CGST and SGST. When they are in different states, IGST applies. Getting this wrong is one of the most common invoicing errors.
A simple example
| Item | Taxable value | GST 18% | Total |
|---|---|---|---|
| Service fee | ₹10,000 | ₹1,800 | ₹11,800 |
Within one state, the ₹1,800 is shown as ₹900 CGST and ₹900 SGST. Between states, it is shown as ₹1,800 IGST.
Mistakes to avoid
- Skipping or duplicating invoice numbers.
- Missing or wrong customer GSTIN.
- Applying the wrong rate or the wrong HSN/SAC code.
- Not keeping copies. Store invoices safely and back them up.
Larger businesses may also need e-invoicing. Check the current thresholds and rules for your turnover.