* The key code: This is a number that corresponds to the specific cuts on the key. Ford would have this on file, potentially, but accessing it might require proof of ownership.
* The VIN (Vehicle Identification Number): This can sometimes help, but it doesn't directly provide the key code in most cases.
* A working key: This is the easiest route for a locksmith. They can use this key to make a copy.
In short, your best bet is to try obtaining the key code from Ford or a dealership. If you can provide proof of ownership, they may be able to assist. Otherwise, you might need to explore a more involved process involving potentially replacing the ignition cylinder itself. This would be a more costly solution.
