GSTIN Validator

How GSTIN is structured

A GSTIN is 15 characters: 2-digit state code + 10-char PAN + 1 entity number + Z + checksum. The checksum uses a base-36 weighted sum, so a typo anywhere in the GSTIN typically produces an invalid checksum.

Position by position:

• 1–2: state code per the GST notification (07 Delhi, 27 Maharashtra, 33 Tamil Nadu, etc.). 99 is reserved for Centre.
• 3–12: PAN of the registered person. The 4th character indicates the entity type (P=person, C=company, H=HUF, F=firm, etc.).
• 13: entity number for the same PAN in the same state. Most taxpayers are “1”; multiple business verticals or branches under one PAN go 2, 3 and so on.
• 14: fixed letter Z, reserved by design for future use.
• 15: checksum (0–9 or A–Z) computed from the prior 14 characters.

What this tool checks vs the GST portal

The format and checksum are mathematical properties of the string — this tool verifies both, instantly and offline. The GST portal's “Search Taxpayer” feature additionally confirms that the GSTIN was actually issued, by which legal name, on which date, with which return-filing status. Use this validator for bulk pre-checks (vendor onboarding spreadsheets, invoice ledgers); use the portal to verify a single vendor before payment.

Common GSTIN typos this catches

• Wrong state code (e.g., 03 isn't a valid Indian state — Punjab is 03; 04 is Chandigarh).
• PAN substring with a digit where a letter belongs (positions 6–9 must be digits, 1–5 and 10 must be letters).
• Missing the entity number, leaving 14 characters total.
• Last-digit transcription errors — almost always caught by the checksum.

Related tools

For valid PAN format-checking alone, see the PAN validator. To look up a 6-digit HSN code for a goods classification, use the HSN lookup. To generate a tax-compliant GST invoice with this GSTIN, see the GST invoice generator.