Free tool
GSTIN validator: check a GST number in seconds.
Paste a GSTIN to check that it is well-formed: the state code exists, characters 3 to 12 are a PAN, and the last character matches the check digit worked out from the first fourteen. A single mistyped character almost always breaks the check digit, so this catches most typing errors before they reach an invoice or your GSTR-1.
Checked in your browser — nothing is sent anywhere. A correct format does not prove the GSTIN is registered or active; search it on the GST portal (gst.gov.in → Search Taxpayer) before you rely on it for input tax credit.
What each part means
State code
Maharashtra
PAN of the business
PAN holder type: Firm / LLP
Registration number
Which GST registration this is under the same PAN in this state
Default letter
"Z" on GSTINs issued today
Check digit
Matches the first 14 characters
How a GSTIN is built
| Characters | What they are | Example (27AAPFU0939F1ZV) |
|---|---|---|
| 1–2 | State code of the registration | 27 = Maharashtra |
| 3–12 | PAN of the business | AAPFU0939F |
| 13 | Registration number under that PAN in the state (1–9, then A–Z) | 1 |
| 14 | Default letter, "Z" today | Z |
| 15 | Check digit calculated from the first 14 characters | V |
What this check can and cannot tell you
It proves the number is well-formed and catches typing mistakes. It cannot prove the GSTIN is registered, active or belongs to the business in front of you — that needs the GST portal. Before you claim input tax credit on a supplier’s invoice, search the GSTIN on gst.gov.in under “Search Taxpayer” and check the legal name and status.
TripleBill runs the same check whenever you save a customer or supplier GSTIN, so a mistyped number is caught before it reaches a B2B invoice or your GSTR-1.
How to validate a GSTIN
- 1
Paste the GSTIN
Copy the 15-character GSTIN from the invoice or the customer and paste it in the box; spaces and small letters are fixed for you.
- 2
Read the result
Green means the format, state code and check digit are all correct; red lists exactly which part is wrong.
- 3
Check the breakdown
Confirm the state matches where the business is registered and the PAN holder type fits (company, firm, proprietor).
- 4
Confirm on the GST portal
For a new supplier, search the GSTIN on gst.gov.in to see the legal name and whether the registration is active.
Frequently asked questions
Is this GSTIN validator free?
Yes. No signup, and the check runs in your browser — the GSTIN is not sent to any server.
Does a valid result mean the GSTIN is active?
No. It means the number is correctly formed. Registration status and legal name are only on the GST portal (gst.gov.in → Search Taxpayer).
What is the check digit?
The 15th character is calculated from the first 14 with a modulus-36 formula. If any one character is mistyped, the check digit usually stops matching.
Why does my GSTIN have a letter in the 13th place?
The 13th character counts registrations under the same PAN in the same state: 1 to 9, then A to Z for the tenth registration onwards.
What do the state codes mean?
They are the GST state codes, e.g. 07 Delhi, 27 Maharashtra, 29 Karnataka, 33 Tamil Nadu. 97 is Other Territory and 99 Centre Jurisdiction.
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