Master key or master keying is the capability to use one "Master" key to open one or more locks that are not actually keyed the same. Master keys are commonly used in commercial setups where the master key holder may have a key to their office's main door that can also open the bathroom, or a maintenance staff may have a master key that opens every door in the same building.

Master keys are also used by landlords or landladies in apartment complexes where they have a master key that could open a door in each flat, and each occupant possess their own keys for a specific unit as well. This key can also be used to open the building's main entry door including other common areas in the apartment. But it cannot open other units unlike master keys.

Multiple master, grand master, and sub master keys may be involved in the master key system making it a complex system. If you want to have one key to all different doors, then master key is what you need.

We can make the proper master key systems depending on your key holder. When in an urgent locksmith emergency trouble, make sure to call our locksmiths at our emergency hotline number. Our customer support is available 247.