The $60 a spare saves you
Adding a key to a car that already knows one is short work. The car trusts the working key, the programmer asks it to accept another, and nothing else in the car changes. When every key is gone, the key code has to come off the VIN and the immobilizer gets programmed from scratch. That extra work is the $60.
A Honda smart key made as a spare starts at $239. The same fob, ordered once no key is left, starts at $299. A Honda dealer quotes about $480 for it either way, then adds $125 to $200 for towing because a car with no key cannot be driven in, and the fob may sit on order for one to three days.
Why a hardware store copy is only half a key
A key machine copies the teeth. On most cars built since the late 1990s, the teeth only turn the lock; the engine runs only after a chip in the head answers the immobilizer. A copy with no chip unlocks the door and turns the ignition, and then the engine cranks and stalls, or does not crank at all, depending on the make.
Some stores can clone the chip on certain older keys. Newer chips use encryption built to defeat copying, and laser-cut blades need a cutter most stores do not own. A clone also carries your original key's identity rather than its own, so if the original is ever lost and erased from the car, the clone stops working with it.
Cars that want the working key at the appointment
On many turn-key Fords, two working keys let you add a third, already cut, yourself with a timed ignition routine from the owner's manual. With only one key, the car needs a programmer, and that is the visit we make.
Older Toyotas split keys into a master with a black head and a valet with a gray head, and on many of them only the master can authorize a new key. On many Honda and Acura models, programming with no working key present drops every stored key from the car, and each one has to be registered again. If you are down to one key, see what happens when it goes too.
What the one-year warranty covers on a spare
The key, the remote buttons and the programming, for twelve months. If the key stops starting the car, a button quits, or the car forgets the key inside that year, we come back and put it right. A key that goes missing is not a warranty case. That is the job the spare was made for.