You should call a locksmith anytime you need to secure your home, offices, premises, assets and valuables from intruders, theft, etc and to satisfy insurance requirements.Additionally call a locksmith to change the locks whenever you lose a key or move into a new location, especially if someone was occupying the place before moving in.Another time to call is when you get locked out of your home/premises, car, or safe. A skilled locksmith can gain access for you with causing very little damage.In short, anything to do with keys, locks, and safes.