If a Contact is archived it is not removed from the system but is made inactive. This means that no future activities can be associated with the contact, but any existing activities will still show the contact, although it will not be available for editing or viewing more information.
Invoice for an active Contact
An Invoice that has been generated for a Contact that is active in the system will have the contact available as a link.
Invoice for an Archived Contact
An Invoice generated for a Contact that has subsequently been archived will NOT have the contact available as a link.