Key cancellation

Key cancellation means making that key stop opening the lock, even though it still exists and someone may have it in their pocket.

Some cylinders are designed for this: that is the case with the construction key, which cancels itself when the owner’s key is used, and with certain systems that let you lock out a particular key. With most ordinary cylinders it is not possible, and the way to achieve it is to change the cylinder.

You need it when a key is lost or stolen, when a tenancy ends, when the person who looks after the house changes or when you buy a resale property. If you do not know whether your cylinder allows it, the practical thing is to change the lock cylinder and have peace of mind.