Classification Structure• 6 min read• Published Sep 2026
Understanding HSN Code Lengths
Understand chapter, heading, subheading, and tariff-item prefixes when browsing the HSN dataset.
Classification levels
The first two digits identify a chapter; four digits identify a heading; six identify a subheading; eight can identify a tariff item. This describes the structure of records in the dataset, not the number of digits required on a particular invoice.
Lookup is not invoice validation
The API looks up records from a community-maintained snapshot. It does not check current invoice rules, turnover thresholds, effective dates, or whether a code is accepted by an invoicing portal.
Browse a chapter
curl "https://gst-hsn-sac-api.vercel.app/v1/hsn/chapters/09?limit=50&offset=0"
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