Locksmiths use key codes to cut keys that match the exact specifications of a lock. By entering the code into specialized software, locksmiths can replicate the keys and cut new ones. If you can provide an identity document and proof of ownership, your local dealer may be able to search for your vehicle's key code for a fee. However, rates vary from dealer to dealer and not all dealers will be able to generate a key code for you.
For instance, many Chevy dealers don't give out the key codes (they want you to tow the vehicle to their workshop), and Ford only keeps the codes for 10 years, so if you have an 11-year-old F150, your only option would be to have a key made from the vehicle's existing locks. No, although it may save you some money if you have one, there is no need for an automotive locksmith to generate a new set of replacement keys for your vehicle.