GSTIN Validator

What this validator actually checks

A GSTIN is a fixed 15-character identifier, and its characters are not arbitrary. The first two digits are the state code, the next ten are the PAN of the registered person, the thirteenth is the registration count for that PAN within the state, the fourteenth is the letter Z for most registrations, and the fifteenth is a checksum character calculated from the preceding fourteen.

This tool recalculates that checksum and inspects each segment. If a digit was mistyped or two characters were swapped, the checksum will not match and the number is rejected before you ever send it anywhere. The check runs entirely in your browser and nothing is submitted to the GST network.

Structural validity is not registration status

A GSTIN can be perfectly well-formed and still belong to a registration that was cancelled last year, or to no registration at all. The validator cannot tell you either of those things. Once a number passes the format check, run it through GST verification to see the registration details and current status, and confirm anything consequential against the official GST portal.

Who finds this useful

Accounts teams keying supplier numbers into an accounting system, anyone building a form that collects GSTINs, and buyers sanity-checking a number printed on an invoice before raising a query with the supplier.