Address Book/Customer Master set up

When we set up a new customer, we set them up in the address book and in the customer master.  We do the same for our ship to addresses. 

The issue we are having is that order entry is selecting the ship to address as the sold to (by mistake). 

Do I have to set up the ship to addresses in the customer master for them to the on the sales order in the ship to location?

Or can I block the ship to addresses from being entered as a sold to address on a sales order?

We are on JDE 9.1 with tools 9.1.4.6.