What customer data does a tax invoice need?

For a tax invoice (a customer with a VAT number) ZATCA requires:

• VAT number: 15 digits, starting and ending with 3.
• Full national address: street, district, city, region and postal code (5 digits).
• For a customer in Saudi Arabia also: building number (4 digits) and additional number (4 digits).

Enter them on the customer card before invoicing; if something is missing, a warning names it and the invoice is not saved.

A simplified invoice (individuals) needs none of this.