Rekeying is changing a house, office or automotive lock thus allowing a different key to operate it. Rekeying is done when a lock owner may be concerned that unauthorized people have keys to the lock. The lock may be altered by a professional locksmith thus only new keys will work. Rekeying is the relatively simple process of changing the tumbler or wafer configuration of the lock thus a new key will function while the old one will not. Rekeying is done without replacement of the entire lock, saving you money.