GSTIN (India GST number) validation: checks the 15-character format and the chec...
https://agentstall.padawanconsulting.com/v1/india-gstinOverview
GSTIN (India GST number) validation: checks the 15-character format and the check character, and decodes the state, the embedded PAN and the type of PAN holder (company, individual, firm, trust and others). Format check only, not a GST portal registration lookup; the number is not stored. Useful for invoices, vendor onboarding and KYB forms for Indian businesses, and for catching typos.