The status of the customer you described sounds like the status of the opportunity associated to the customer record. The opportunities status are values like Active, Inactive and Sold. There are sub status there in also. The opportunity status is currently read only. The ELead team is working in the current wave for helper methods needed for an ISV to fetch possible opportunity status and sub status. Future work, not assigned to any future wave, we will have stories for altering the status and sub status of an opportunity. This would be the way to mark an opportunity sold or inactive.