GSTIN Validator

The GSTIN validator checks whether a GST identification number is well formed, without sending it anywhere. A GSTIN has fifteen characters, and every part means something: the first two are the state code, the next ten are the holder’s PAN, the thirteenth counts registrations under that PAN in that state, the fourteenth is normally Z, and the last is a check character worked out from the other fourteen. The tool checks each part and tells you which one is wrong — the quickest way to catch a mistyped GSTIN on an invoice before it reaches your return.

1. Type or paste a GSTIN. Spaces and dashes are ignored, and lower case is fine.
2. Read the result: each check is listed with what it found, such as the state and the holder type.
3. To check many at once, paste a list with one GSTIN per line; the result becomes a table.
4. For a well-formed number, search it on the GST portal to confirm it is registered and active.

• Well formed is not the same as registered. A number can pass every check and still be cancelled, suspended or belong to someone else — only the GST portal can tell you that.
• The check character catches any single mistyped character, and most swaps of two neighbouring characters, but not every possible combination of errors.
• UINs for embassies and UN bodies, OIDAR registrations and some other special registrations use different patterns; the tool recognises the UIN pattern and says so rather than calling it invalid.
• State codes include the older codes 25 (Daman and Diu) and 28 (undivided Andhra Pradesh), which still appear on existing registrations.
• Up to 500 lines are checked at once.
• Everything is checked in your browser. The numbers you paste are not sent to any server, not even the GST portal, and are not saved.

Each of the first 14 characters is given a value from 0 to 35 (0–9, then A–Z) and multiplied alternately by 1 and 2. The results are reduced and added, and the check character is whatever brings the total to a multiple of 36. This is the Luhn mod 36 method GSTN uses.

Its fourth character says what kind of holder it is: P for an individual, C for a company, F for a firm or LLP, H for a Hindu Undivided Family, T for a trust, and so on. A company invoice with a P in that position is worth a second look.

It counts registrations under the same PAN in the same state: 1 to 9, then A to Z for the 10th to 35th. A business with several branches in one state can have several.

Not here — that needs the GST portal’s records. Use “Search Taxpayer” on the GST portal, which the result links to.