GSTIN

GSTIN is the 15-character ID issued by the GST authority when you register for GST. The format is fixed: 2-digit state code, 10-digit PAN, 1 entity-number digit, 1 default Z, 1 checksum.

For Robnu, GSTIN appears on every customer invoice and (depending on the marketplace) on the vendor invoice. We validate the format on signup and flag malformed GSTINs before they hit a customer's invoice.

When paid pricing eventually launches, GSTIN is also how Robnu issues GST-compliant tax invoices for the subscription. During early access there's nothing to invoice, so GSTIN is optional.