GST knowledge

GSTIN format — the 15-character structure explained

Every GST number follows the same pattern. Once you can read it, you can spot a fake GSTIN at a glance.

Example: 27ABCDE1234F1Z5

27ABCDE1234F1Z5
PositionSampleMeaning
1–227State codeThe two-digit code of the state or union territory where the taxpayer is registered. 27 is Maharashtra, 29 is Karnataka, 07 is Delhi.
3–12ABCDE1234FPAN of the taxpayerThe ten-character Permanent Account Number of the business or person holding the registration. This ties GST to income-tax records.
131Entity numberHow many registrations that PAN holds within the same state. The first registration is 1, the second 2, and so on (1–9, then A–Z).
14ZDefault characterCurrently always the letter Z. It is reserved for future use by GSTN.
155ChecksumA check digit calculated from the first 14 characters. It lets any system detect a mistyped GSTIN before making a lookup.

The example above is a structural illustration, not a real taxpayer. See every GST state code to decode the first two characters of any GSTIN.

Need to verify a GSTIN right now?

Format checks tell you a number is plausible. Only a live lookup tells you the registration is real and active.

Example:

Frequently asked questions

How many digits are in a GSTIN?

A GSTIN is 15 characters long — a mix of digits and capital letters, not 15 digits only.

What does the first two digits of a GSTIN mean?

They are the GST state code of the state or union territory where the registration was granted.

Can one PAN have several GSTINs?

Yes. A business needs a separate GST registration in each state where it operates, and can hold multiple registrations in one state. The 13th character distinguishes them.

Why does my GSTIN get rejected before the search runs?

We validate the length, the character pattern and the checksum locally. If any of those fail, the number cannot exist, so we tell you immediately instead of running a lookup.