Kia Optima 2004 Owner's Manual page 17

5) If you need additional keys or if
you should lose your keys, your
authorized Kia dealer can make
new keys if you can supply the key
number and ID key.
NOTICE:
If you make your own duplicate
key, you will not be able to cancel
the system or start the engine.
3-8
KNOWING YOUR VEHICLE
KEY NUMBERS
The vehicle key number is recorded
upon a metal tag attached to the keys
when the vehicle is first delivered to you.
The key number should be recorded and
kept in a safe place in case the need to
order further keys arises. New keys are
available from any Kia dealer by quoting
the relevant key number.
In the interest of security, the metal tag
attached to the keys which bears the key
number should be removed from the key
ring after you receive your new vehicle.
In addition, key numbers cannot be
provided by Kia for security reasons.
If you need additional keys or if you
should lose your keys, your authorized
Kia dealer can make new keys if you can
supply the key number and ID key.
EMSA3070A