Free tool
Is that GSTIN real, or a typo?
The fifteenth character of a GSTIN is a checksum over the first fourteen, so most typos can be caught arithmetically. This is the same function fynxIQ runs over every GSTIN in every return it prepares.
Type or paste a GSTIN to check its structure and its check digit.
What the fifteen characters mean
Reading a GSTIN.
| Position | Holds | Example |
|---|---|---|
| 1 to 2 | State or union territory code | 29 for Karnataka |
| 3 to 12 | The PAN of the business | AAAAA0000A |
| 13 | Which registration this is under that PAN in that state | 1 for the first |
| 14 | Registration type. Z is a regular taxpayer, C is a TCS collector | Z |
| 15 | Check digit, computed from the first fourteen | 5 |
Because the PAN sits in the middle, every registration a business holds across states shares the same ten characters. That is what lets fynxIQ derive a marketplace’s TCS registration in your state once you have supplied one of them, instead of hard-coding a value that would be wrong the day you register somewhere else.
A valid check digit does not mean the registration is active or that the business is who it says it is. It means the number was not mistyped, which is the failure that actually happens when a B2B invoice is keyed in by hand.
fynxIQ checks the supplier GSTIN, every buyer GSTIN and every operator GSTIN on every return, and treats a failure as a blocker. See the rest of the checks →