Use cases · for KYB and finance teams
How to verify a GSTIN number (format, checksum, state and PAN)
Last updated 2 November 2026 · by Venu Gopal Reddy Muvva, founder
A GSTIN is 15 characters: a 2-digit state code, the business's 10-character PAN, an entity number, the letter Z and a check character. IndianFirmData checks all of this for free. Paste the number in Dashboard → Verify an ID, or call GET /api/v1/identifiers/decode?value=<GSTIN>. You see whether the checksum is right, which state it belongs to and the PAN inside it. Live registration status from the GST network is not available yet.
Steps in IndianFirmData
1. Open Verify an ID
Sign in and open Dashboard → Verify an ID. You can also do this from the API without the dashboard.
2. Paste the GSTIN
Paste the 15-character number and press Check. Lower case is fine.
3. Read the result
You see valid or invalid, the reason when it is invalid, the state from the first two digits, the embedded PAN and what kind of holder the PAN belongs to.
4. Find the company
If a company in our index carries that exact number, a link to its profile appears next to the result.
What a checksum check catches
The last character of a GSTIN is calculated from the first fourteen. A typing mistake in any one character almost always breaks it, so a failed checksum tells you the number was copied wrongly or made up. A passing checksum tells you the number is well formed. It does not tell you the registration is active; that needs the GST network.
Other numbers it checks
The same check works for CIN, PAN, Udyam, LEI and ISIN numbers. Each one is decoded into its parts: a CIN shows listing, industry code, state, year and company class; an LEI is checked against its ISO 17442 check digits; an ISIN against its Luhn check digit. Every one of these checks costs 0 credits.
When IndianFirmData is not the right tool
If you must confirm that a GST registration is active today, or see the business's filing history, you need a licensed GST Suvidha Provider. Our live GST status lookup is built but not switched on until we sign one.
Questions
Is the GSTIN check really free?
Yes. Verify and decode calls cost 0 credits, during the free period and after it.
Do you scrape the GST portal?
No. The portal's search is behind a CAPTCHA, and we never automate it.
Can I check many GSTINs at once?
Call the decode endpoint once per number from your own code; each call is free.
Try it on a company you know.
Start free — 3 months on usRelated: Check a company is real · Decode a CIN number · IndianFirmData vs Apollo.io API · Pricing