GSTIN is 15 characters: 2-digit state code + 10-digit PAN + entity code + Z + checksum
How to Read a GSTIN
2 7 A A B C U 9 6 0 3 R 1 Z X
27
State Code
AABCU9603R
PAN Number
1
Entity No.
Z
Default
X
Checksum
🗺️
State Code (Characters 1–2)
Two-digit code representing the state/UT where the business is registered. E.g., 27 = Maharashtra, 07 = Delhi, 29 = Karnataka.
🪪
PAN Number (Characters 3–12)
The 10-character PAN of the business or individual. Must follow the PAN format: 5 letters + 4 digits + 1 letter (e.g., AABCU9603R).
🏢
Entity Number (Character 13)
Indicates how many registrations a PAN holder has in a state. 1–9 for individuals, A–Z for companies/LLPs/partnerships.
✅
Checksum (Character 15)
Algorithmically calculated from the first 14 characters. Any error in the GSTIN changes this digit — helping detect fake or mistyped GSTINs.
Common GSTIN Errors
| Error | Cause | Fix |
|---|---|---|
| Wrong length | Extra or missing characters | Ensure exactly 15 characters |
| Invalid state code | Wrong first 2 digits | Verify state of registration |
| PAN mismatch | Wrong or mistyped PAN | Cross-check PAN on Income Tax portal |
| Checksum failure | Typing error or fake GSTIN | Re-check from GST registration certificate |
| 14th char ≠ Z | Data entry error | Character 14 must always be "Z" |