What should be done about keys held by former residents or staff?

The safe thing is to make those keys useless, because even if they are handed back you do not know whether copies were made.

There are several ways:

• Rekeying the cylinder, if it is one that allows it: the combination changes and the old keys stop opening it.
• Replacing the cylinder with a new one, which is the simplest option when there are few doors.
• In a master key system, cancelling only that person’s key without touching the others, if the system allows it.

In communities it happens with the caretaker who retires, the cleaning company that changes or the resident who sells up and, without realising, takes a copy of the entrance key with them. In businesses, with staff who leave.

To stop it happening again, a protected key cylinder and a key register are the answer. We look at it in master key systems.