GSTIN Validator

A GSTIN has 15 characters: two-digit state code, ten-character PAN pattern, an entity character, a default Z, and a checksum. This page checks that pattern and the checksum arithmetic. The sample 22AAAAA0000A1Z5 is the well-known dummy pattern (state 22) that usually fails checksum — which is exactly why it is a good teaching value. It is not a live taxpayer search on gst.gov.in.

A number you need in a queue

Accounts teams in Surat and freelancers in Bengaluru paste GSTINs from WhatsApp. A checksum catch stops a GSTR-1 mismatch later. IndiaKit will not log you into the GST portal and will not ask for OTP.

How the lookup or formula runs

Regex: 2 digits, 5 letters, 4 digits, 1 letter, 1 alphanumeric, Z, 1 alphanumeric. Then a weighted checksum over 36-character alphabet as used for GSTIN. Default sample is 22AAAAA0000A1Z5, which should fail checksum after passing format.

A pass here does not mean the dealer is active, not cancelled, not a composition taxpayer. Only gst.gov.in search (and your vendor’s invoice) can say that.

Do not paste Aadhaar. GSTIN is a business tax ID; still, treat it as business data, not as a password.

Teaching dummy 22AAAAA0000A1Z5

An intern in Surat pastes 22AAAAA0000A1Z5. Format passes; checksum fails; the page says the GSTIN is not valid. She then pastes the vendor’s real GSTIN from a tax invoice and, if structure passes, still verifies on gst.gov.in.

What we do not store

Structure and checksum only. Not a live GST portal lookup, not a filing tool. Official: gst.gov.in. No OTP.

Common questions

Why does the official-looking dummy fail?

Because the last character is a checksum, not a random Z-digit. CBIC teaching examples are meant to show format, not to pass a real checksum.

Does a checksum pass mean I can claim ITC?

No. ITC needs a valid invoice, GSTR-2B, and blocking rules. This page never sees your returns.

Is the first two digits the state?

Yes in the GSTIN design (22 is Chhattisgarh’s code in the dummy). Confirm state codes in GST documentation if you need the list.