GSTIN Validator
Updated September 2026
Check whether a GSTIN is correctly formatted and passes the official checksum algorithm — a quick first check before invoicing or filing.
⚠ Verify before filing. Results are estimates based on the law as applied at the date shown above. Tax rules change — always confirm the current rate or provision at the official source (CBIC or Income Tax Department) before raising an invoice or filing a return. Last reviewed: August 2026.
GSTIN Validator
Frequently Asked Questions
What does a GSTIN validator actually check?
It checks that the 15-character structure is correct (2-digit state code + 10-character PAN + entity code + 'Z' + checksum) and that the final checksum character matches — it does not confirm the GSTIN is active or registered.
How do I check if a GSTIN is actually registered and active?
Use the official GST portal's "Search Taxpayer" tool, which confirms live registration status, legal name, and filing status — this calculator only checks the number's format.
What are the first two digits of a GSTIN?
The first two digits are the state code where the business is registered — for example, 27 is Maharashtra and 07 is Delhi.