First create a parent record for accounts payable.
Next you are going to create the primary contact accounts payable.
Now, create a new service location for this customer. Click on the [Locations/Contacts]
The service location is going to be the work site. Differentiate the name just enough that it is clear what this record is for:
Notice that you have a different primary contact for service location. From within the service location click on [Locations/Contacts] and create an Additional Contact(s).
Now whenever your customer calls for service at their service location you will create the opportunity or job from this customer record. It is set-up now to provide the contact name, phone, and email address of the primary contact at the job site.
Lastly, when the opportunity is won and the job is completed