GSTIN Validator
Paste any 15-character GSTIN to check its format, state code, embedded PAN, and checksum digit — instantly, in your browser.
This tool checks format and checksum only — it does not confirm live registration status on the GSTN network. Verify active registration on the official GST portal.
What the 15 characters of a GSTIN mean
Every GSTIN follows the same anatomy, which is what makes offline validation possible:
- Characters 1–2 — state code. The state or union territory of registration (e.g. 07 for Delhi, 27 for Maharashtra, 29 for Karnataka).
- Characters 3–12 — PAN. The Permanent Account Number of the business or proprietor.
- Character 13 — entity code. Counts the registrations held by the same PAN within the state (1–9, then A–Z).
- Character 14 — the letter Z. Reserved by default in the current format.
- Character 15 — check digit. A checksum computed from the first 14 characters that catches typos and fabricated numbers.
Why validating GSTINs matters for your business
A wrong GSTIN on a purchase invoice can cost you input tax credit, and a wrong GSTIN on a sales invoice creates mismatches in your buyer's returns. Running a quick format and checksum check when you onboard a new customer or supplier catches most typos immediately. For full assurance, follow up with a taxpayer search on the official GST portal, which shows the legal name and registration status. Billing software like Brihat Books validates GSTINs as you type so bad numbers never reach your invoices.
GSTIN Validator FAQs
GSTIN (Goods and Services Tax Identification Number) is the 15-character registration number issued to every business registered under GST in India. It encodes the state of registration, the business PAN, an entity code for that PAN within the state, and a checksum character.
Never invoice a bad GSTIN again
Brihat Books checks customer and supplier GSTINs automatically and keeps your invoices and returns consistent.
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