Run the number through a format check first: a wrong check digit, an unknown state code or a PAN pattern that does not fit means the number is invalid. Then search it on the GST portal (Search Taxpayer > Search by GSTIN/UIN). "No records found" means it does not exist; Cancelled or Suspended means it is not usable; and a legal name different from the business in front of you means it is being misused.
Three kinds of fake, three checks
| Problem | How to catch it |
|---|---|
| Number does not exist (typo or invented) | Format and check digit: GSTIN validator. Portal shows "No records found". |
| Real number, no longer valid | Portal status: Cancelled, Suspended or Inactive. |
| Real active number, wrong business | Portal legal name and trade name do not match the purchase order, letterhead or bank account name. |
Quick signs before you even search
- Not 15 characters, or contains characters other than capital letters and digits.
- First two digits are not a GST state code, or do not match the address given.
- Characters 3 to 12 do not look like a PAN (five letters, four digits, one letter).
- The 4th PAN letter does not match the business: P (individual) for a company, or C (company) for a proprietor.
- The 14th character is not Z.
The validator checks all of these and recalculates the check digit. But a determined fraudster can produce a correctly formed number, so always follow with the live check.
The live check on the GST portal
- Open www.gst.gov.in. You do not need to log in.
- Go to Search Taxpayer, then Search by GSTIN/UIN.
- Enter the 15-character GSTIN, type the captcha and click Search.
- Read the result: legal name, trade name, effective date of registration, constitution of business, GSTIN/UIN status, taxpayer type, administrative office, principal place of business and nature of business activities.
- Click Show Filing Table to see which returns were filed, for which period and on what date.
Compare the legal name with the name on the purchase order and on the bank account the buyer pays from. FundRaksha Trust puts the status, names and filing record on one screen.
Why it matters to a supplier giving credit
For a supplier, the danger is not mainly tax; it is getting paid. A buyer who gives a fake or borrowed GSTIN is, at best, careless and, at worst, planning not to pay. When the invoice goes overdue you will need to name the right party in a legal notice, a Section 138 complaint or a Samadhaan claim; a GSTIN that belongs to someone else makes that harder. For buyers, the risk runs the other way: credit claimed on invoices from a non-existent supplier can be reversed with interest and penalty.
Worked example: a Kolkata electrical wholesaler receives an order for ₹2,90,000 from a new "company". The GSTIN fails the check digit. Corrected by the buyer, it now passes, but the portal shows the legal name of a proprietor in another city. The wholesaler declines credit and offers supply against advance. The buyer stops responding.
Last reviewed: 2026-10-21. Information for Indian businesses; not legal advice.