HSN Code Explained: What It Is and Why Every GST Invoice Needs It

What is an HSN Code?

HSN code is a six-digit (extendable to eight-digit) internationally recognised numerical classification system, developed by the World Customs Organization, used to systematically classify goods for taxation, trade and customs purposes, and adopted by India for classifying goods under the GST regime to ensure a uniform tax structure across the country.

Before GST, India used different classification systems across excise, VAT and customs, which created confusion and inconsistency. Adopting HSN codes uniformly under GST means the same product carries the same classification and, generally, the same tax rate treatment regardless of which state it is sold in.

HSN Code Structure Explained

How is an HSN code structured?

An HSN code is organised hierarchically: the first two digits represent the chapter, indicating the broad category of goods; the next two digits represent the heading, narrowing down the product group; and the following two digits represent the sub-heading, specifying the exact product, with India extending this further to eight digits for even more precise classification for domestic purposes.

For example, in the code 6109 10, the chapter 61 refers to articles of apparel and clothing accessories that are knitted or crocheted, the heading 09 narrows this to t-shirts, singlets and similar garments, and the sub-heading 10 further specifies the material composition, such as cotton.

Mandatory HSN Digits Based on Turnover

Businesses with turnover up to Rs 5 crore have historically been permitted to declare HSN codes optionally on B2C invoices while it remained mandatory on B2B invoices at the applicable digit level, though this specific carve-out has been tightened over successive GST notifications, so businesses should confirm the current applicable requirement on the GST portal for their turnover slab and invoice type before finalizing their invoicing format.

How to Find the Correct HSN Code

• Identify the broad category your product falls under, referring to the GST HSN code list published on the official GST portal or the CBIC website.
• Narrow down to the specific chapter and heading that matches your product’s core function or material composition.
• Use the GST portal’s HSN code search tool, which allows searching by product description or partial code to find the exact matching entry
• Cross-check the applicable GST rate linked to that HSN code, since rate notifications are tied directly to specific HSN classifications
• Where a product could plausibly fall under more than one heading, consult the General Rules of Interpretation that govern HSN classification, or seek an advance ruling from the GST authority if the ambiguity carries meaningful tax exposure

HSN Code vs SAC Code

What is the difference between HSN code and SAC code?

HSN code classifies goods, while SAC code, short for Services Accounting Code, classifies services under GST; a business dealing exclusively in physical products uses HSN codes on its invoices, a business providing services uses SAC codes, and a business dealing in both needs to correctly apply each classification system to the relevant line items on a single invoice.

SAC codes generally follow a similar structured numbering approach but are specific to the services sector, covering categories like professional services, transportation, telecommunications and financial services, each with its own applicable GST rate.

Common Mistakes with HSN Codes

• Using an outdated HSN code after a product classification has been revised through a GST Council notification, resulting in incorrect tax rate application
• Declaring fewer digits than mandated for the applicable turnover slab, which can trigger a notice or penalty during GST return scrutiny
• Applying a broadly similar but technically incorrect HSN code because the exact match was not properly searched for, leading to mismatched tax rates compared to what suppliers or buyers have declared for the same product
• Failing to update HSN codes across the entire product catalogue when GST rate notifications change specific classifications, leaving legacy invoices or catalogue entries misaligned

Key Takeaways

• HSN code is an internationally standardised system for classifying goods, adopted by India under GST to ensure uniform tax treatment nationwide.
• The mandatory number of HSN digits on a tax invoice depends on annual turnover, ranging from 4 digits for smaller businesses up to 8 digits for specified categories.
• HSN codes classify goods while SAC codes classify services, and businesses dealing in both need to apply the correct system to each relevant invoice line item.
• Using the GST portal’s official HSN search tool is the most reliable way to find the correct code for a specific product.
• Outdated or incorrect HSN codes are a common cause of GST return mismatches and scrutiny notices, so codes should be reviewed whenever rate notifications change.

FAQs

How many digits does an HSN code have in India?

An HSN code can have 4, 6 or 8 digits depending on the context, with the mandatory number of digits on a GST tax invoice determined by the business’s annual turnover in the preceding financial year.

Is HSN code mandatory for small businesses under GST?

Businesses with annual turnover up to Rs 5 crore are generally required to declare at least a 4-digit HSN code on their tax invoices, though the exact requirement for B2C versus B2B invoices should be confirmed against current GST notifications.

What is the difference between HSN code and SAC code?

The HSN code is used to classify physical goods under GST, while SAC code, or Services Accounting Code, is used to classify services, and each carries its own applicable GST rate structure.

Where can I find the correct HSN code for my product?

The correct HSN code can be found using the official HSN code search tool on the GST portal or the CBIC website by searching using the product’s description or a partial code.

What happens if I use the wrong HSN code on an invoice?

Using an incorrect HSN code can result in applying the wrong GST rate, which may trigger a mismatch during return scrutiny, additional tax liability, interest or penalty depending on the nature and materiality of the error.

Does the HSN code determine the GST rate applicable to a product?

Yes, GST rate notifications are directly tied to specific HSN classifications, so correctly identifying the applicable HSN code is essential to applying the right GST rate on your invoices.

Talk to Growthora

Getting HSN classification right across your entire product catalogue protects you from GST mismatches and unnecessary scrutiny. Book a free consultation with Growthora Advisory’s GST compliance team for a review of your invoicing and classification setup.