If you are purchasing the property, then you have carte blanche to rekey or change out the locks in whatever way you wish, subject to code and the demands of the fire marshal.  On rentals, the situation is a bit more complicated.  Rental companies and individual landlords have the right to ask that renters make use of a particular keyway, provide  them a key to the property, and allow that keyway to be master keyed. This means that the renter has an individual key to their home or apartment, and the landlord has that same individual key, as well a master key that works on all their other units.  Most condominiums will maintain a key cabinet with all the individual unit keys  (change keys), but may also have a master key that opens all units.  Renters who change out their locks or do key changes without providing a key to the landlord, might be liable if there is a water or gas leak, or if someone becomes locked inside their unit.  Water leaks in multi-level condos or apartments must be dealt with quickly to avoid damage to lower units, and having quick access to those units is a must.

Since mailbox locks are not rekeyable, they cannot be master keyed.  Postal gang boxes are accessible from the back for postal employees, so individual keys are not necessary to gain access.

Mountain Locksmith can do master keying on residential and commercial locks of most types, and provides a wide variety of mailbox locks and tail pieces.  If the key to the mailbox is lost, we pick open or drill out the mailbox lock, which is generally of two types: common (light duty), and USPS mailbox locks, which are very heavy duty, and come with a right and left hand turn.  Gang boxes themselves are generally all light duty, or all USPS heavy duty.  Both types of locks are pickable and drillable, although the USPS locks are more pick proof, and harder to drill.  Neither type of lock is expensive. We carry a very wide variety of tail pieces for mailbox locks, and can fabricate special tailpieces on the spot to fit the requirements of any mailbox compartment.   Drill-outs are generally ten to thirty dollars, depending on the number of bits used.  New mailbox locks come with two factory cut originals, and Mountain Locksmith can cut as many duplicates as you wish, right on the spot.

With respect to home and business owners who wish to carry out rekeying and lock change-outs on newly purchased properties, the fire marshal is the final arbiter on what types of locks are permitted for that particular property.  High security locks are always allowable, but double sided locks which prevent ready egress might or might not be allowable.  This applies mostly for commercial doors where a fire or security problem prevents anyone, during or after business hours, from immediate exit even if they do not have a key.  Double sided mortise cylinders on commercial entry doors prevent egress without a key.  The idea here is to prevent thieves from using that entry door to carry out items after business hours.  The problem here is that if there is a fire, a gas leak, or any security problem, and if someone is locked in the premises after hours, they may not be able to escape. The owner of that property is then liable.  Many businesses throughout Colorado Springs have double cylinder mortice cylinders at the front, and double cylinder deadbolts at the back.  They may have fail safe or fail secure magnetic locks with or without key overrides which allow or prevent immediate exit.  In all cases, check with the fire marshal to see what she requires, but also keep in mind the business owner’s liability if someone is hurt because they are locked inside.