I'm assuming from what little i know about customs, this address information is logged and held here?

What we need to understand is how this connected to a customer record and then how that pulls through to the CO when an order is raised.

Also on the shipment screen as this is the point they would print/email the document. Is there a field where this shows the Customs ID which would be connected to the customer order record? 

Any help with this would be great

Thanks