GSTIN checker: is this GST number right?
Type a GSTIN to check its format and check digit, and see what each part means — state, PAN, holder type. It catches most typing mistakes before they reach an invoice or a GST return.
This sample is made up for the demo — type your own.
✓ Well-formed GSTIN
The format and check digit are correct. This does not prove the number is registered or active — check that on the GST portal.
What each part means
32AAACX1234K1ZL
- 1–2 · State
- 32 — Kerala
- 3–12 · PAN
- AAACX1234K
- PAN holder
- Company (4th letter “C”)
- 13 · Number
- Registration 1 under this PAN in this state
- 14 · Default
- Z
- 15 · Check
- L
How a GSTIN is built
Every business registered under GST gets a 15-character Goods and Services Tax Identification Number. It is not random — each part carries meaning:
- Characters 1–2: state code. The state where the business is registered — 32 for Kerala, 27 for Maharashtra, 29 for Karnataka, 33 for Tamil Nadu.
- Characters 3–12: the PAN of the business or person. Its 4th letter shows the type of holder — P for an individual, C for a company, F for a firm, H for an HUF.
- Character 13: entity number. One PAN can have several registrations in the same state (for separate business verticals); this counts them 1–9, then A–Z.
- Character 14: “Z” by default.
- Character 15: check character, worked out from the first 14.
How the check digit works
The last character is a checksum. Each of the first 14 characters is turned into a number (0–9 stay as they are; A = 10 … Z = 35). Every second one is doubled. Each result is written in base 36 and its two “digits” are added; all of these are summed. The check character is whatever brings that sum up to the next multiple of 36. Change any single character — the commonest typing mistake — and the check character no longer fits. That is how this page can tell you a number is wrong without looking it up anywhere.
Valid is not the same as registered
A number can pass every check here and still be fake, cancelled or suspended. Before you pay a supplier or claim input tax credit on their invoice, search the GSTIN on the GST portal’s “Search Taxpayer” page: it shows the legal name, the status (Active / Cancelled) and the date of registration. Input tax credit is only allowed when the supplier is genuinely registered and has reported the invoice.
GST state codes
For commerce students
GST registration, invoices and input tax credit come up in Class 11 and 12 Accountancy and in Computerised Accounting. If you are learning to keep GST records, our free Excel course shows how to build an invoice register, and the other free tools cover goodwill, ratios and income tax.
By the ACES team · Last checked 6 November 2026