GSTIN Validator
Check a GSTIN's structure, state code and checksum — offline, instantly.
How the calculation works
A GSTIN encodes state, PAN, entity number and a checksum. Every character has meaning — this validator decodes and verifies them offline.
- Structure
2-digit state + 10-char PAN + 1st entity digit + Z + check char - Check digit
Modulo-36 weighted sum of first 14 chars → 15th char
Worked example
Checking 27ABCDE1234F1Z5 from a new supplier's invoice.
You enter
You get
Important points to keep in mind
- This checks structure only — registration status, legal name and filing history need the official portal search.
- Checksum failure usually means a typo; verify against the source document before rejecting outright.
- The tool runs entirely in your browser; nothing you paste leaves the device.
Frequently asked questions
Can this tell me if a GSTIN is cancelled?
No — live status requires the government database. Use the GST Portal's 'Search Taxpayer' for authoritative status.
Why does the check digit matter?
It catches transcription errors — swapped characters or wrong digits almost always break the checksum.
What does the 13th character mean?
The entity/branch serial within the same PAN — '1' for the first registration, up to Z after numbers exhaust.
Related GST tools
Prepare your returns in GSTSelf
Done estimating? Prepare the actual return.
GSTSelf walks you through your invoices, builds GSTR-1 and GSTR-3B data, and keeps everything on your device — no uploads, no account.