In Hindi: जीएसटीआईएन · Also called: GST number, GST identification number
GSTIN, the GST Identification Number, is the number a business gets when it registers for GST. It is 15 characters long, and each part means something: the first two digits are the code of the state it is registered in, the next ten are the business's PAN, the next two are the entity code, and the last is a checksum.
Because the state is built into the number, a GSTIN also tells you where a registered buyer is registered, which is part of working out whether a sale is within the state. Registration is state by state, so a business registered in two states has two GSTINs with the same PAN inside them.
The seller's GSTIN goes on every tax invoice, and the buyer's too when the buyer is registered. Anyone can check that a GSTIN is real, and see the legal name behind it, on the GST portal's taxpayer search.
