Purchase Orders that are exported to a PDF will have an area for your billing and shipping address along with the vendor's address.
The billing address will come from the address entered into the "Company" tab of the Settings page. To get there, click on "Settings" in the top navigation menu, then Company" on the left menu bar.
The "Ship to" address will come from the address specified on the individual location record. For more information about how to create a new location, click here.
The vendor address will come from the vendor record. Click here to learn more about creating a new vendor.