Certificate of Occupancy (CO)

A certificate of occupancy (CO) is the official document a building department issues to confirm that a structure complies with the applicable building code and is legally safe to occupy. It is usually the last step in a new-construction or major-renovation project: the permit is issued, the work is built and inspected, and once it passes final inspection the AHJ grants the CO.

For data users, a CO is a strong signal that a project actually reached completion — distinct from a permit merely being issued. Not every jurisdiction publishes COs as separate records; many fold the milestone into a permit's final status. Where it appears, PermitStack treats it as part of the permit lifecycle rather than a separate object, and a permit reaching a final status is the closest universal proxy. Related: permit status and new construction permit.