GSTIN Validator.

No, this tool validates the structure and the check digit of a GSTIN, but it does not query the live government database, so it cannot tell you whether a registration is currently active, cancelled or suspended. What it does is confirm that the 15-character number is well-formed: that the state code is real, that the embedded PAN follows the correct pattern, and that the final check digit computes correctly, which together catch the great majority of typos and fake numbers people enter. To confirm a supplier actual registration status, use the official search at gst.gov.in, where you type the GSTIN and see the legal name, the registration date and whether it is active. The smart workflow is to run a structural check here first, instantly and privately, to weed out obviously invalid numbers before you bother with the official portal, then verify the survivors on gst.gov.in before you claim input tax credit against their invoices, since credit on an invalid or cancelled GSTIN can be denied.

The check digit is the fifteenth and final character of a GSTIN, and it is not chosen freely; it is mathematically derived from the first 14 characters using a modulo-36 algorithm over the base-36 alphabet, which is the digits 0 to 9 plus the letters A to Z. Because it is computed from everything before it, the check digit acts as a built-in error detector: it is specifically designed to catch single-character typos and most transposition errors, the everyday mistakes someone makes keying a long number off an invoice, such as swapping two characters or mistyping one. If even one character in the GSTIN is wrong, the recomputed check digit will usually no longer match, and this tool flags the number as invalid. That is why a structural check is such a cheap, fast first line of defence: before you ever hit the government portal, the check digit alone exposes a large share of mistyped or fabricated GSTINs in a fraction of a second.

The entity character is the 13th character of the GSTIN, sitting just before the Z and the final check digit, and it indicates the registration sequence number for that particular PAN within that particular state. In plain terms, it counts how many GST registrations a single business entity, identified by its PAN, holds in one state. Most ordinary businesses have just one registration per state, so you will very commonly see a 1 here. A higher value, such as 2, 3 or a letter, appears when the same PAN holds multiple registrations in the same state, which happens with separate business verticals, or in cases of re-registration after an earlier registration was cancelled. It is a useful sanity signal: an unusually high entity character on a GSTIN you were not expecting it on is worth a second look, though on its own it is perfectly legitimate and simply reflects how that business has structured its registrations within the state.

Position 14, the second-to-last character, is almost always the letter Z because the GST format reserves that slot as a default placeholder for current normal registrations, which is what the overwhelming majority of GSTINs are. In other words, Z is the expected, standard value you should see there on a typical taxpayer GSTIN, so if you spot a different character in that position it is worth double-checking. The other possible letters at this position were set aside by the GST Council for future use, for instance to denote additional registration categories, but those alternatives have not been activated in general practice, so for everyday verification a Z is exactly what you want to see. This tool checks that position 14 holds the expected value as part of confirming the number is well-formed, which is another small structural signal that, combined with the state code, the embedded PAN pattern and the check digit, tells you whether a GSTIN someone gave you is plausibly genuine.

No, the GSTINs you check are never sent anywhere; all the validation logic runs entirely in your own browser. When you type or paste a number, the structural checks, the state code lookup, the embedded PAN pattern match, and the modulo-36 check-digit calculation all execute locally on your device, with no network request carrying your data to us or to any third party. That means you can safely paste in a long list of supplier or customer GSTINs to clean up before filing, without worrying that those business identifiers are being logged on someone else server. Because nothing leaves the page, the tool is also instant, with no waiting on a round trip to a server. The one thing to remember is that this on-device privacy comes hand in hand with the tool limitation: since it never contacts the government, it confirms only that a number is well-formed, not that the registration is live, for which you would visit gst.gov.in separately.

State code 28 is flagged as legacy because it originally belonged to undivided Andhra Pradesh, before the 2014 bifurcation that carved out the new state of Telangana. After that reorganisation, the GST state codes were realigned: Telangana was assigned code 36, and newly issued registrations in the reorganised Andhra Pradesh use code 37, while the old code 28 was effectively retired for fresh registrations. So when you see 28 on a GSTIN today, you are almost always looking at an older registration issued under the pre-bifurcation numbering that has simply carried forward, rather than a brand-new one. It is not invalid, it is just historical, which is why the tool notes it as legacy rather than rejecting it. If you are verifying a supplier in the Andhra or Telangana region and the state code surprises you, this context explains it: 28 is the old code, 36 is Telangana, and 37 is current Andhra Pradesh.

Yes, absolutely, and this is the single most important limitation to understand. A GSTIN that has been cancelled or suspended by a GST officer does not change its characters, the 15-digit number stays exactly the same, so it still passes every structural test here: the state code is real, the embedded PAN is correctly formed, and the check digit still computes. This tool verifies that the number is well-formed, not that the underlying registration is still alive. That gap matters commercially, because if you claim input tax credit on an invoice from a supplier whose registration was cancelled, the credit can be disallowed and you bear the cost. So treat a green result here as necessary but not sufficient: it tells you the number is genuine in form, after which you should confirm the live status on gst.gov.in, especially before onboarding a new supplier, claiming significant credit, or whenever something feels off about a counterparty.

It validates the PAN pattern embedded inside the GSTIN, but it is not a full PAN verification service. Every GSTIN contains the business 10-character PAN sitting in characters 3 through 12, and that PAN follows a fixed structure of five letters, then four digits, then one letter. This tool confirms that the embedded portion matches that standard pattern as part of judging whether the overall GSTIN is well-formed, which catches a mistyped or fabricated PAN within the number. What it does not do is check that PAN against the Income Tax Department records to confirm it actually belongs to a real, active taxpayer with a matching name. For that deeper confirmation, use the official PAN verification service offered through the Income Tax e-filing portal or an authorised KYC provider. In short, this gives you a fast structural sanity check on the PAN inside a GSTIN, and you escalate to the official PAN service only when you need legally authoritative identity confirmation.