The renovation that ended with forty keys
An eighteen-month build finishes. Over that time keys went to a main contractor, three subcontractors, a site foreman, an interior designer and whoever was letting the tilers in on a Saturday. Nobody kept a list.
There is no way to audit that after the fact, so the only honest answer is a full reset — every external cylinder changed, ideally onto a restricted profile so the new keys cannot be casually copied. It is a single planned visit at the end of a project, and it converts an unknown into a known.