How To Add Multiple Warehouses To Suppliers

If you would like to add all of a supplier's warehouses so that you can select the preferred shipping point when ordering, go to Suppliers>Manage Suppliers.

Locate the supplier you would like to edit.  Scroll to the Shipping Address section and click Edit.  Then click Add New in the top right.  If you would like this location to be the default warehouse/location, toggle the Default Address to turn green.