This would not be a valid invoice in Sweden. Here, there needs to be a reference number, VAT registration number, information about interest rate if late paymen

This would not be a valid invoice in Sweden. Here, there needs to be a reference number, VAT registration number, information about interest rate if late payment, location of the board if the selling company is a limited company, and probably a few more things. I think the same applies for most EU countries. Can US invoices be this simple?