GSTIN validator and decoder

A GSTIN is the 15-character GST identification number that India's GST system gives to a registered taxpayer. A business registered in several states gets a separate GSTIN for each one, because GST has no single registration for units in different states. You will usually find it on a supplier's invoices.

Characters 1 and 2 are the state or UT code. Characters 3 to 12 are the PAN of the holder. Character 13 is the entity number, which counts the registrations under that PAN in that state (usually 1 to 9, then A to Z). Character 14 is usually the letter Z. Character 15 is a check digit worked out from the first 14. The GST Council's flyer describes the state code, the PAN, an entity code and a check sum; the finer points on the 13th and 14th characters come from public references.

No. It only checks how the number is written. A GSTIN that passes is correctly formed; that does not show it is registered, active, suspended or cancelled, or whose it is. Use Search Taxpayer on the GST portal for that. It asks for a captcha and, without logging in, shows details such as the legal name, trade name, registration date and cancellation date where one applies. This page never contacts the portal.

Usually a character was mistyped or two neighbours were swapped, the number was copied with a character missing or added, or the document it came from has a typing mistake. The result lists the positions that break the layout. If the layout is fine but the check digit does not match, at least one character is not what it should be, and this page cannot say which one. Copy the number again from the invoice or the registration certificate instead of guessing.

Most GSTINs have Z there, and the python-stdnum documentation describes it as fixed. Public explainers also say that C and D are used for tax collectors and tax deductors, and the government's e-invoice API schema takes any letter or digit in that place. So this page treats any other character in the 14th place as unusual, shows a note, and lets the check digit decide. It does not call a number wrong for that alone.

Take characters 3 to 12. In the sample 27AAAAA0000A1Z2 that is AAAAA0000A. The fourth letter of the PAN, which is the sixth character of the GSTIN, shows the holder type: 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 A, B, G, J or L for the other types. For a sole proprietor, the PAN inside the GSTIN is the owner's personal PAN.

For the layout this page checks, use ^[0-9]{2}[A-Z]{5}[0-9]{4}[A-Z][0-9A-Z]{3}$ on the upper-case number: two digits, five letters, four digits, one letter, a digit or a letter, then two more letters or digits. It is written for the usual PAN-based GSTINs: special identifiers, such as a tax deductor registered on a TAN, can follow another layout. It does not insist on a Z in the 14th place, because some GSTINs carry C or D. A pattern cannot check the last character: that comes from the first 14 by the Luhn mod 36 method, so it takes a small calculation, not a pattern. A pattern also cannot tell you whether the state code is on the list or whether the GSTIN is registered.

No. This page reads India's 15-character GSTIN and nothing else. Canada's GST/HST account number is a 9-digit business number followed by RT and a 4-digit reference. New Zealand's GST number is the same as the IRD number. In Australia, a business's GST registration is listed on ABN Lookup. This page checks none of those, so use the tax authority's own tools.

No. The check runs in your browser. Nothing you type or paste is uploaded, saved in your browser, put in the web address or reported to analytics, and the page does not contact the GST portal. The one link that leaves this page goes to the portal and carries no number. Results disappear when you close or reload the page.