Currently, only one VAT ID can be defined for a customer. This may be undesirable for some companies that are tightly related to other legal entities or have sub-companies they want to create orders for. In that case, multiple customer accounts would need to be created for proper invoicing.

The database structure already has a field to store a VAT ID with an address, so it would be useful to allow saving different VAT IDs depending on the address, so that customer can choose them during checkout.