How to verify a GST number (and spot a fake one)

Last reviewed: 27 September 2026 · By the GSTRisk team · General information, not tax advice.

Before you pay a new supplier, record their GSTIN in your books or extend credit to a customer, spend two minutes confirming the GST number is real and belongs to the business you are dealing with. A wrong or fake GSTIN can cost you the input tax credit on every invoice from that supplier.

In short: check the format and check digit, look the number up on the GST portal, confirm the name, state and status match the invoice, and glance at the return filing table. The whole check takes under two minutes.

Step 1: Check the format and the check digit

A GSTIN has exactly 15 characters: a two-digit state code, the business’s 10-character PAN, a registration number, the letter Z (by default) and a final check character calculated from the first 14. If even one character is mistyped or invented, the check character will not match.

Paste the number into the GSTRisk GSTIN checker. It checks the format and the check digit instantly in your browser and decodes the state, PAN and type of holder. Most fake GSTINs fail here. The GSTIN format guide explains each part.

Step 2: Look it up on the GST portal

Open the Search Taxpayer page on gst.gov.in. You do not need to log in.
Enter the GSTIN, fill in the captcha and press Search.
The portal shows the legal name, trade name, date of registration, constitution of business, taxpayer type, GSTIN status and principal place of business, and a cancellation date if there is one.

You can also press Check live GST status under a valid result in the GSTRisk checker to see the same registration details in one click.

Step 3: Match the details to the invoice

Check	What should match	Why it matters
Name	Legal or trade name on the portal matches the name on the invoice	A valid GSTIN copied from another business is a common trick
Status	Active	Invoices from a cancelled or suspended registration may not give you valid credit
State	State code (first two digits) matches the supplier’s billing state	A Maharashtra GSTIN on a Kolkata supplier’s invoice needs an explanation
Constitution	Company, firm or proprietorship matches how the supplier presents itself	An invoice from “XYZ Pvt Ltd” with a proprietor’s GSTIN is a red flag
Taxpayer type	Regular, if the invoice charges GST	A composition taxpayer cannot charge GST on its invoices

Step 4: Glance at the return filing table

On the same Search Taxpayer result, press Show Filing Table, choose the financial year and press Search. You will see which returns the supplier has filed and when. Your input tax credit depends on the supplier reporting your invoice in their GSTR-1, so a supplier with gaps in filing is a risk even if the registration is active. See how to read the filing table.

Red flags that deserve a second look

The check digit does not match, or the GSTIN has the wrong number of characters.
The status is Cancelled, Suspended or Inactive, or a cancellation date is shown.
The name on the portal does not match the invoice.
The registration is only a few weeks old and the order is large, with no references.
The supplier is a composition taxpayer but has charged GST on the invoice.
The return filing table shows months with no GSTR-1 or GSTR-3B filed.
The supplier asks you to pay GST into a different account from the invoice amount.

None of these proves fraud on its own. They are reasons to ask the supplier for an explanation and documents before you pay.

How often should you check?

Check every new supplier before the first payment, and re-check existing suppliers regularly. A registration that was active last year can be suspended or cancelled today, for example after months of non-filing. The free supplier watchlist re-checks your list every 30 days and emails you if a status changes.

Check a supplier now: use the free GSTIN checker for the format and live registration status, or add your whole supplier list to the free supplier watchlist and get an email if a registration changes.