GSTIN Validator
🔒 In your browserCheck a GST number's format, state code & checksum.
How it works
Check whether a GSTIN (Goods and Services Tax Identification Number) is valid. It verifies the 15-character format, the state code, and the built-in checksum digit — all in your browser.
A valid format and checksum confirm the number is well-formed — it does not confirm the GSTIN is currently active or registered. Verify status on the official GST portal.
🔒 Calculated entirely in your browser — nothing is uploaded.
🔒 Calculated in your browser: your loan, investment and salary figures are never uploaded. Interest, tax and salary structures vary by bank and employer, so treat the result as a close estimate and confirm exact figures with them.
About the GSTIN Validator
This free GSTIN validator checks whether a GST Identification Number is well-formed. It verifies the 15-character structure, the state code, and the built-in checksum digit, and shows the state and the holder's PAN — all in your browser.
Nothing is uploaded; the check runs locally.
How a GSTIN is structured
- Characters 1–2: the state code (e.g. 27 for Maharashtra).
- Characters 3–12: the PAN of the business.
- Character 13: the entity/registration number for that PAN in the state.
- Character 14: the letter Z (reserved).
- Character 15: a checksum digit computed from the first 14 characters.
What the checksum proves (and doesn't)
The 15th character is a mod-36 checksum over the first 14, so a single mistyped character almost always fails validation. Passing the checksum confirms the number is internally consistent and correctly formatted — but it does not confirm the GSTIN is registered or currently active. For that, verify the number on the official GST portal.
Frequently asked questions
How do I check if a GST number is valid?
Paste it here — the tool verifies the 15-character format, the state code and the checksum digit instantly. A green result means the number is well-formed.
What does the GSTIN checksum do?
The last character is a mod-36 checksum of the first 14, so a typo in any character almost always makes it fail. It catches transcription errors, not registration status.
Does a valid format mean the GSTIN is active?
No. A valid format and checksum only confirm the number is well-formed. To confirm it's registered and active, check it on the official GST portal.
What is the state code in a GSTIN?
The first two digits identify the state or union territory of registration — for example 27 is Maharashtra, 07 is Delhi and 29 is Karnataka. The validator shows the state for you.
Is the GSTIN I enter uploaded?
No. Validation runs entirely in your browser.
Related searches
Related Finance tools
🔗 Embed this tool on your website — free
Copy this and paste it into your page's HTML. The tool runs in the visitor's browser, just like here. Change height to fit, or add the optional auto-resize snippet below. Add ?theme=dark to the URL for dark mode.
<iframe src="https://toolhq.dev/embed/gstin-validator/" title="GSTIN Validator — ToolsHub" width="100%" height="520" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" loading="lazy"></iframe>Optional: auto-resize the iframe height
Add this once on the same page so the iframe grows to fit the tool:
<script>
addEventListener("message", function (e) {
if (e.data && e.data.type === "toolshub:resize") {
document.querySelectorAll('iframe[src*="/embed/"]').forEach(function (f) {
if (f.contentWindow === e.source) f.style.height = e.data.height + "px";
});
}
});
</script>