What does a GSTIN look like?

A GSTIN is 15 characters. The first two digits are the state code, the next ten are the PAN of the registrant, the 13th is an entity number, the 14th is the letter Z, and the 15th is a checksum character.

Does a valid checksum mean the GSTIN is registered?

No. A passing checksum only means the number is internally consistent and free of typos. To confirm the business is actually registered and active, use the search taxpayer tool on the official GST portal.

How is the GSTIN checksum calculated?

Each of the first 14 characters maps to a base-36 value, is multiplied by an alternating factor of 1 and 2, and the sum of the quotient and remainder of dividing by 36 is accumulated. The check character is 36 minus that total, taken modulo 36.

Can I read the PAN from a GSTIN?

Yes. Characters 3 to 12 of the GSTIN are the PAN of the registered person, so the PAN is always embedded in a valid GSTIN.

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GSTIN validator

Paste a GSTIN to check its format and checksum in real time. The tool confirms the 15-character structure, reads out the state code and embedded PAN, and recomputes the check digit.

Enter a GSTIN

GSTIN

15 characters: 2-digit state code, 10-character PAN, entity digit, Z, and a checksum.

Result

Enter a GSTIN above to check it.

How it works

What a GSTIN is made of

A GSTIN is a 15-character identifier built from a state code, the registrant PAN, an entity digit, a fixed letter, and a checksum. The checksum lets a typo be caught without any lookup.

State code and PAN

The first two digits are the state or union-territory code. The next ten characters are the PAN of the registered person, so a GSTIN always carries the PAN it belongs to.

Entity digit and Z

The 13th character shows the registration count for that PAN within the state. The 14th character is the letter Z by default, reserved for future use.

The checksum digit

The 15th character is a base-36 checksum over the first 14. It is a self-check: change any character by mistake and the checksum no longer matches, which this tool detects.

Sources

The GSTIN structure and checksum are defined by the GST system administered by CBIC. Verify a registration status against the official portal below.

This checks the format and the checksum only. A GSTIN can be well-formed yet not currently registered or active. Confirm a live registration on the official GST portal search. This is not tax advice.

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