HSN & SAC Codes: How Classification Actually Works

Every item on a GST invoice needs a classification code that determines its tax rate: HSN for physical goods, SAC for services. Getting this wrong is one of the more common — and costly — invoicing mistakes.

HSN codes (goods)

HSN (Harmonized System of Nomenclature) is an internationally standardised classification system, not something India invented for GST — the same base codes are used in customs and trade documentation worldwide. An HSN code is structured hierarchically: the first two digits identify the chapter, the next two the heading, and further digits add detail — a longer code is simply a more specific classification of the same chapter.

SAC codes (services)

SAC (Services Accounting Code) is India's own GST-specific system for services, always a 6-digit code starting with "99". The first two digits after that (positions 3-4) indicate the broad service category, and the last two narrow it further.

Who needs how many digits

The exact digit requirement scales with annual turnover — smaller businesses can use a shorter (less specific) code, larger ones must use a longer, more precise one. The smallest businesses may be exempt from mandatory HSN reporting altogether below a turnover threshold. SAC codes are generally expected from service providers in return filings regardless of turnover. Confirm the current threshold table on the GST portal, since it has been revised by notification before.

How to actually find the right code

1. Start from what the product or service actually is and does — not the brand name. "Wireless earphones" classifies differently than searching the brand that makes them.
2. Use the official HSN/SAC search tool on the GST portal, which lets you search by description and returns candidate codes with their current rate.
3. Where a product could plausibly fit two chapters, check the chapter notes (exclusions/inclusions) — GST classification disputes very often come down to exactly this kind of boundary case.

What goes wrong when it's wrong

An incorrect code can apply the wrong tax rate (under or over-charging), delay or block the buyer's Input Tax Credit, invalidate the invoice if left blank where required, and in serious or repeated cases, attract penalties. A business selling both goods and services needs to correctly split invoice lines between HSN and SAC — using one system for both is a common error.

Key takeaways

• HSN classifies goods; SAC classifies services — the systems aren't interchangeable.
• Required code length scales with turnover — check the current threshold rather than assuming.
• Always verify via the GST portal's official search rather than guessing from memory or a competitor's invoice.