What is an HSN code? How to find the right HSN/SAC for your invoice

An HSN code is a standard number that classifies goods, and an SAC code does the same for services — GST invoices use them so every product and service is taxed consistently. If you sell goods you quote an HSN code; if you sell services you quote an SAC code. Getting the right one keeps your invoice compliant and your tax rate correct.

HSN and SAC in one line each

• HSN (Harmonised System of Nomenclature) — an internationally used system for classifying goods. India uses it under GST to identify products.
• SAC (Services Accounting Code) — the equivalent classification for services.

Both link an item to its GST rate, so the code and the tax rate go together.

Why GST invoices need them

The code is how the tax system knows what you sold and at what rate. It appears on your GST invoice against each line, flows into your returns, and helps prevent disputes about whether you charged the right rate.

How many digits must you show?

The number of HSN digits required depends on your aggregate turnover, and the requirement has been tightened in stages. As a general shape: smaller turnovers show fewer digits, larger turnovers show more, and B2B invoices can have stricter requirements than B2C. Because these thresholds change by notification, confirm the current digit requirement for your turnover band rather than relying on an old figure.

How to find the right code

1. Start from the product/service description. Be specific — "cotton t-shirt" not just "clothing."
2. Use the official GST rate finder / HSN search on the GST portal to match your item.
3. Check the GST rate that comes with the code and confirm it matches what you intend to charge.
4. When in doubt, ask your CA — misclassification can mean the wrong tax rate.

Save codes once, reuse forever

The practical trick is to store the code against each product so you never look it up twice. In Invoicify, your product catalogue holds the HSN/SAC and tax rate, and the invoice line pre-fills them when you pick the product. That is a big time-saver for retailers and traders and wholesalers with large catalogues.

Classification feels tedious the first time, but it is a one-off: set the codes on your products once and every future invoice is correct by default.