Business Lookup
GSTIN Validator
Checksum and format validation, with state code lookup.
Checked entirely in your browser — nothing you type here is sent anywhere.
How a GSTIN is structured
A GSTIN is 15 characters: a 2-digit state code, the taxpayer's 10-character PAN, a registration number for that PAN within the state (usually 1, or higher if the same PAN holds multiple registrations there), a fixed 'Z', and a checksum character computed from the first 14. This tool checks the format, decodes the state and PAN holder type, and recomputes the checksum — it confirms the GSTIN is well-formed and internally consistent, not that it's currently active or registered to a real business.
Confirm it's a real, active registration on the GST portal
- Go to the GST portal's "Search Taxpayer" page using the button below.
- Select "Search by GSTIN/UIN".
- Enter the 15-character GSTIN and the captcha shown, then click Search.
- Check the result: registration status (Active / Cancelled / Suspended), legal and trade name, and date of registration.
Example
27AAPFU0939F1ZV decodes to state code 27 (Maharashtra), embedded PAN AAPFU0939F (entity type "F" — Firm), registration number 1, and a checksum that matches — a well-formed, internally consistent GSTIN.
Frequently asked questions
Does a valid format mean the GSTIN is real and active?
No — this tool only confirms the GSTIN is well-formed and internally consistent (correct length, pattern, and checksum). It doesn't check whether that GSTIN is actually registered, active, cancelled, or suspended. Use the GST portal's "Search Taxpayer" link above for that.
What are the 15 characters of a GSTIN?
A 2-digit state code, the taxpayer's 10-character PAN, a 1-digit registration number for that PAN within the state, a fixed 'Z', and a 1-character checksum computed from the first 14 characters.
What does a checksum mismatch mean?
It usually means a typo somewhere in the GSTIN — a transposed digit or wrong character. The checksum is a mod-36 check digit computed from the first 14 characters, so even a single-character error will make it fail.
How is a GSTIN related to a PAN?
Characters 3 to 12 of a GSTIN are the taxpayer's actual PAN, and the 4th character of that PAN indicates the holder type — for example P for an individual, C for a company, or F for a firm.
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