if its the standard keyless system, then you can buy fobs easily, and there is a procedure for programming them. - can't remember exactly but it involves having all they keys you want to use, and part of the procedure is to press the engine on/off button 8 times...
if its the more advanced keyless entry (little sensor on the door handle, and remote read of key), - don't know but I think dealer or specialist is the way to go.
whats wrong with the key you have?, may be repairable?
Sorry I should have pointed out, the main fobs been lost, or misplaced, so we're working with the standby. The car has what gremlin calls the advanced system, sensing the fob within about 20feet, and the grey buttons in the door handles.Any info is a help. Thanks.
I think it's probably best left to Ford, though quite expensive. Timpsons do them, but I don't think they can do the b max keyless entry ones and there is a programming procedure involving the cars inbuilt electronics.