What an HSN Code Is
An HSN code (Harmonized System of Nomenclature) is a globally standardised number used to classify goods. In India, every product on a GST invoice needs the correct HSN code, because the code determines the GST rate that applies. Services use the equivalent SAC code (Services Accounting Code). Getting the code right is not a formality — a wrong HSN code can mean the wrong tax rate, a GST notice, or blocked input tax credit for your buyer.
How Many Digits Do You Need?
How much of the HSN code you must report depends on your turnover:
- Turnover up to ₹5 crore: 4-digit HSN codes on B2B invoices.
- Turnover above ₹5 crore: 6-digit HSN codes are mandatory.
- Exporters: 8-digit HSN codes are required.
More digits mean a more specific classification. Using too few digits, or the wrong ones, is a common audit trigger, so match the requirement for your turnover band.
Why the Right Code Matters
- Correct GST rate: The HSN code maps to a slab under the GST 2.0 structure (0%, 5%, 18%, 40%). Wrong code, wrong rate.
- Compliance: Mismatched HSN codes between invoices and returns invite scrutiny.
- Your buyer’s ITC: An incorrectly classified invoice can create problems in reconciliation.
- Consistency: The same product should always carry the same HSN code across invoices.
For the rates each code maps to, see our GST 2.0 slab list.
How to Find the Right HSN Code
There are a few reliable ways:
- The official GST portal has an HSN/SAC search under Services, and you can look up codes by product name or code even before logging in.
- Free HSN finder tools let you search by product description — including our own GST rate finder.
- Your billing software can store the code against each product so it auto-fills on every invoice.
Search by the most specific description of your product, then confirm the code matches the exact category — small differences in wording can change the code and the rate.
HSN vs SAC — Goods vs Services
Use HSN codes for goods and SAC codes for services. A shop selling products uses HSN; a business providing services (repairs, consulting, transport) uses SAC. Some businesses supplying both will use each where relevant on the same invoice.
Common HSN Code Mistakes
- Guessing a code instead of verifying it against the official list.
- Using too few digits for your turnover band.
- Applying one product’s code to a similar-but-different product.
- Letting the code and the applied GST rate drift out of sync.
- Re-typing codes manually on every invoice, inviting errors.
The Simplest Long-Term Fix
Look up each product’s HSN code once, store it against the item in your catalogue, and let your billing software apply it automatically on every invoice. This removes the biggest source of error — manual entry — and keeps codes and rates consistent. It is the same principle as auto-filling a customer’s details from their GSTIN.
Conclusion
The right HSN code is what makes a GST invoice charge the right tax and stay compliant. Match the digit requirement to your turnover, verify codes against the official list rather than guessing, and store them once so they auto-fill forever. InfiBis keeps HSN codes and GST rates on your product master so every invoice is accurate by default — and you can use our GST rate finder to look up a code in seconds. For the full invoicing walkthrough, read how to create a GST invoice.