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GSTIN Format Checker

Validate a GSTIN and read its state code — 100% free, runs in your browser

This checks the structure and the built-in check digit only. It confirms a number is well formed — it cannot confirm the business is registered or active. For that, use the official GST portal.

About the GSTIN Format Checker

A GSTIN has a fixed structure: two digits of state code, ten characters of PAN, an entity number, the letter Z, and a check digit calculated from everything before it. This tool verifies that structure and recalculates the check digit, which catches typos and obviously fabricated numbers straight away.

How to use it

  1. Type or paste the 15 character GSTIN.
  2. Results appear as you type.
  3. Check each line — state code, PAN section, and the check digit.

Common questions

Does this prove the business is registered?

No, and this distinction matters. It only proves the number is correctly formed. A number can pass every check here and still belong to a cancelled registration. For live status, use the official GST portal.

What is the check digit?

The fifteenth character, calculated from the previous fourteen. It exists so that a single mistyped character is detected rather than silently accepted.

My state is missing from the list.

Then the first two digits are not a valid state code. Recheck them against the invoice — this is the most commonly mistyped part.

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