Purpose of associating a Bill-To site to a Ship-To site in the Customer Master

Summary:

Hi Experts,

We are looking to understand the purpose of associating a Bill-To site to a Ship-to address in the customer master.

Content (please ensure you mask any confidential information):

Our scenario is that we have 2 Bill-to sites for a customer with multiple Ship-To Sites. Each of these Ship-To sites are linked to one of the 2 Bill-To Sites. Our expectation was that when creating a Sales Order for a Specific Ship-To, the associated Bill-To would default as the Bill to Address.

However, we have noticed that the Bill-To site that is defaulted is the Site marked as Primary. (This is the case for our AR Invoices as well)