GSTIN validator.
Checksum + state + entity decode.
Paste any GSTIN to verify its 36-character checksum and decode the embedded state code, PAN, and entity type. Runs entirely in your browser — nothing is sent to the GST portal.
Format: SS-PPPPPPPPPP-E-Z-C
SS = state · P = PAN (10 chars) · E = entity # · Z = literal 'Z' · C = checksum
What this checks: structure, state-code validity, and the official 36-base GSTIN checksum (CGST Notification 12/2017). What it does notcheck: whether the GSTIN is currently active, suspended, or cancelled — for that you need the GST portal at gst.gov.in. LexVio's Tax AI auto-validates GSTINs on every invoice your team uploads.
Understanding GSTIN validation
A GSTIN (Goods and Services Tax Identification Number) is the 15-character unique ID issued to every business registered under GST in India. It encodes the state, the underlying PAN, the entity number, and a checksum digit. Format validation — what this tool does — catches typos and obvious fakes by re-computing the checksum.
That said, a syntactically-valid GSTIN is necessary but not sufficient. For high-stakes verification — new vendor onboarding, large invoices, B2B credit decisions — combine this format check with the GSTN portal's active-status lookup, which returns the legal name and confirms the registration is not cancelled or suspended.
GSTIN structure at a glance
- Positions 1-2 — State code (01 = Jammu & Kashmir … 37 = Andhra Pradesh).
- Positions 3-12 — The entity's 10-character PAN.
- Position 13 — Entity number for that PAN in that state (1, 2, 3 … then A-Z).
- Position 14 — Always 'Z' (reserved for future use).
- Position 15 — Checksum character, computed via modulo-36 over the first 14.
When to go beyond format validation
- New vendor onboarding — verify legal name and registered address on the GST portal.
- Large invoices — confirm the GSTIN is active and not under cancellation.
- Suspect input tax credit — match invoice GSTIN against GSTR-2A/2B before claiming ITC.
- Cross-state supplies — confirm the buyer's state matches the GSTIN's state code for correct CGST/SGST vs IGST routing.
Frequently asked
What's the structure of a GSTIN?
A GSTIN is exactly 15 characters: positions 1-2 are the state code (e.g., 07 = Delhi, 27 = Maharashtra), 3-12 are the PAN of the entity, 13 is the entity number for that PAN within the state, 14 is always 'Z', and 15 is a checksum character computed using a modulo-36 algorithm. The structure makes it impossible to fake a syntactically-valid GSTIN by typing random characters.
Can I trust a GSTIN that passes the checksum?
Format validation only proves the GSTIN is well-formed — not that it belongs to a real, active business. A determined fraudster can craft a syntactically valid GSTIN. For business-critical verification (large invoices, new vendors), always do a second-level check on the official GST portal (gst.gov.in → Search Taxpayer) which returns the legal name and active/cancelled status.
How do I find the GSTIN for a business?
Three ways. First, the GST portal lets you search by PAN — gst.gov.in → Search Taxpayer → Search by PAN. Second, the company's invoice or letterhead should display it. Third, the MCA portal shows GSTINs linked to registered companies. Marketplaces like Amazon and Flipkart also publish seller GSTINs.
What's a temporary GSTIN (TRN)?
When you start GST registration, you first get a 15-character Temporary Reference Number (TRN). It's used to log back into your in-progress application — not for invoicing or business use. Once registration completes, you receive your permanent GSTIN. Don't confuse the TRN with a valid GSTIN; only the latter passes our checksum.
What if the checksum validation fails?
Almost always a typo — re-check character-by-character, especially I/1, O/0, and B/8. If the same GSTIN was given to you by a vendor and fails validation, ask them to re-confirm or send a screenshot of their GST registration certificate. Never accept a non-validating GSTIN as legitimate; you'll be unable to claim input tax credit and may face penalty on fake-invoice grounds.
Does this tool send the GSTIN to any server?
No. The validation runs entirely in your browser using local JavaScript — the GSTIN never leaves your device. You can verify by opening the browser's network tab while validating. For the deeper portal-based verification (active/cancelled, legal name), you would need to query the GSTN API or use the public search at gst.gov.in.