Rekeying is the process of changing the internal components of a lock so that it works with a new key and Auto Locksmiths can do this. There are a few reasons that this may be needed or requested by the customer. First is that it may be easier than replacing the ignition cylinder altogether.
Ignition rekeying is usually done by an Auto Locksmith so customers will no longer need 2 keys to operate their vehicle. The reason that car owners would need two keys is that a replacement ignition will not be keyed unlike the broken one. New ignitions do come with pre-coded with a few new keys.
Rekeying your ignition is faster and cheaper than servicing all of the car locks. If car doors and trunk locks were not replaced then you’d still need to use the old/original key. It means that if you would like to open up an exterior lock on the vehicle, you would need to have a different key. The option you have after deciding to rekey the lock is that you can rekey all of your exterior locks or just the ignition.