A GSTIN looks intimidating at first — 15 characters mixing letters and numbers. But it's built from five predictable parts.
Take this example: 27AAPFU0939F1ZV
- 27 — the state code. Maharashtra is 27, Delhi is 07, Karnataka is 29.
- AAPFU0939F — the registered business's 10-character PAN.
- 1 — entity number, incrementing if a PAN has registered more than once in a state.
- Z — always the letter Z, reserved by design.
- V — a check digit, calculated mathematically from the other 14 characters.
What decoding tells you (and what it doesn't)
Decoding confirms a GSTIN is correctly formed and tells you the state and embedded PAN. It does not confirm the business is currently active — that requires checking live status on gst.gov.in.
Our GST decoder shows the actual check-digit calculation step by step, not just a pass/fail — nothing hidden.