Guides · GST
HSN codes on invoices
HSN — the Harmonised System of Nomenclature — is the international system for classifying goods. Under GST, a tax invoice must carry the HSN code for the goods it covers so the supply is classified consistently.
What an HSN code is
An HSN code is a standardised number that identifies a category of goods. GST uses it so that the same product is described the same way across every invoice and return, which keeps rates and reporting consistent.
Services use a parallel system called the SAC — the Services Accounting Code — which classifies services the way HSN classifies goods.
How many HSN digits you need
The number of HSN digits a business must show on its invoices depends on its turnover — smaller businesses show fewer digits, larger ones show more. The rule is set by turnover slabs, so it is worth confirming the current requirement for your turnover band.
Using the wrong HSN code can mean the wrong tax rate, which is why the code belongs on the invoice from the start rather than being guessed later.
How Lekha carries HSN
Lekha generates GST-compliant delivery challans and tax invoices against a purchase order, with HSN, place of supply, and the right CGST/SGST or IGST split computed live, and gap-free financial-year numbering.
The HSN sits on the challan and invoice as they are generated, so the classification travels with the document.
Questions
- What is the difference between HSN and SAC?
- HSN classifies goods; SAC classifies services. Both are codes that identify what is being supplied so GST is applied consistently.
- How many HSN digits must appear on an invoice?
- It depends on turnover — smaller businesses show fewer digits than larger ones. Confirm the current slab for your turnover band.
- Does every invoice need an HSN code?
- A GST tax invoice for goods must carry the applicable HSN code. For services, the SAC is used instead.
This guide is general information, not legal or tax advice. Confirm the current rules and your own circumstances for any specific case.