Bill to contact country not mandatory
We are having an integration between Zuora and an ERP in which customers are created based on the data sent from Zuora: organization number (stored in a custom field) + country from the Bill to contact, for avoiding creating duplicates in our ERP system. The thing is that neither in Zuora or in Salesforce the Bill to contact country is not a mandatory field. Country is only mandatory on Sold to contact, so when we try to fetch country from Bill to contact, we oftern get an error becuase this is missing. We cannot use the country from sold to contact to create the customer, because sold to contact's country might differ from bill to contact's country and this would spoil the VAT calculation in the ERP.
My question is... was there any logic behind choosing the country from bill to contact to not be mandatory? If not, is this possible to be changed and put as mandatory field?