Introducing the GST Number Validator — Format & Checksum

A mistyped GSTIN on an invoice can hold up input-tax-credit claims and create filing headaches. The new GST Number Validator catches those mistakes the moment you enter a number.

What it does

• Structure check: confirms the 15-character GSTIN format.
• Checksum: verifies the official mod-36 check digit.
• State code: maps the first two digits to the state or UT.
• PAN + type: extracts the embedded PAN and decodes the taxpayer type.
• Clear verdict: a pass/fail checklist with the exact failing reason.

Why it matters

Format and checksum validation rules out the vast majority of typos in seconds — wrong length, an impossible state code, a transposed character. It won’t replace a portal lookup for legal confirmation, but it stops bad numbers from reaching your books in the first place.

Learn more

Want to understand what each character of a GSTIN means? Our GSTIN structure guide breaks it down, then put it to use in the GST Number Validator.