GSTIN checker
Check that a GST number is correctly formed before it goes on an invoice. See the state, PAN and type of business it contains, and catch typos with the check digit — free, no sign-up.
Free · No sign-up · Updated
This checks the number’s structure only. To see whether it is registered and active, and the business name, use Search Taxpayer on the GST portal.
How a GSTIN is built
Every GSTIN has the same 15-character structure, which is why a typo can usually be spotted without looking anything up.
| Characters | What it is | Details |
|---|---|---|
| 1–2 | State code | The state or union territory of registration — 27 is Maharashtra, 07 Delhi, 19 West Bengal. |
| 3–12 | PAN | The PAN of the business. Its 4th character shows the type: C company, P individual, F firm, H HUF and so on. |
| 13 | Registration number | Which registration this is for the same PAN in that state: 1 for the first, then 2–9 and A–Z. |
| 14 | Default “Z” | Z for regular taxpayers. Special registrations, such as TDS deductors, follow a different pattern. |
| 15 | Check digit | Calculated from the first 14 characters, so a mistyped character makes it fail. |
Why check a GSTIN before you invoice
Your customer claims input tax credit against the GSTIN printed on your invoice, and your GSTR-1 reports the sale against it. A single wrong character can cost the buyer their credit and create mismatches you then have to fix in your returns.
This checker catches mistyped numbers. It can’t tell you whether a GSTIN is registered or active, or who it belongs to — for that, use Search Taxpayer on the GST portal, which is free.
Frequently asked questions
How do I check if a GST number is valid?
Enter it in the checker above. It confirms the GSTIN has 15 characters, a real state code, a correctly formed PAN and a matching check digit. To see whether it is registered and active, and the business name, search it on the GST portal under Search Taxpayer.
What is the format of a GSTIN?
A GSTIN has 15 characters: a 2-digit state code, the 10-character PAN of the business, one character for the registration number of that PAN in the state, the letter Z, and a check digit. For example, 27AAPFU0939F1ZV is a Maharashtra GSTIN.
What is the check digit in a GSTIN?
The 15th character is calculated from the first 14 using a standard formula. If any single character is mistyped, the check digit no longer matches — which is why it is the quickest way to catch a typo.
Can I find the business name from a GSTIN?
Not with this checker: it works entirely in your browser and looks nothing up. The GST portal’s Search Taxpayer shows the legal name, trade name and registration status for any GSTIN.
Why does a wrong GSTIN on an invoice matter?
Your customer claims input tax credit against the GSTIN on your invoice, and your GSTR-1 reports the sale against it. A wrong number can cost them that credit and lead to mismatches in your returns.
Is this GSTIN checker free?
Yes — free, with no sign-up, and nothing you type leaves your browser.
Related
Never print a wrong GSTIN again
Finvosmart checks every GSTIN as you add customers and puts the right one on each GST invoice.
See GST billing software