GSTIN checker
Check that a GSTIN is well formed: its check character, state code and the PAN inside it.
About this tool
A GSTIN is 15 characters: a two-digit state code, the holder's PAN, an entity number, the letter Z and a check character worked out from the rest. A typing mistake almost always breaks the check character.
This checks the number's structure only. Whether it is registered and active is shown on the GST portal's taxpayer search.
Developers: this page runs on the Format checks API (GET /v1/validate/gstin/{value}). Free, open source, no key for most of it.