Differing keys a problem

Question: I rent my apartment and have just discovered that my apartment key fits my friend's apartment that lives in the same building. We compared our two keys and they look different. How can this happen?

Fourchalk: This is a common problem in buildings that don't initiate a proper master-key system. Your building manager obviously has a master key which opens all the apartments. The residents have their individual keys that access their own apartments.

When the master-key system was originally designed, the manager should have had the locksmith create a list of extra key numbers in the event a tenant moved out. This would have eliminated the chances of cross keying.

Cross keying happens when your key fits an area it's not supposed to. This is the result of somebody master-keying locks in your building without referencing the original system list.

I would recommend that you show this article to the manager of your building. Also, request that he contact a locksmith and re-key the building on a proper master-key system for the security of the residents.