I configured the Enable Automatic Assignment to Customer Group based on VAT number
for European customers. It works fine. If a European customer orders and enters a valid VAT number, the VAT is reduced to 0%.
But during checkout the customer doesn't receive feedback on the correctness of the entered VAT number. A lot of customers enter the wrong VAT number and then the VAT is not reduced.
I was expecting feedback to the customer about the validness of the VAT number, but my Magento installation doesn't give this feedback. Is this normal? How can I add this feedback?