Using Peugeot Planet

[Niall]

With the transponder chip (tiny little black thing jammed in the key casing used to start the car), you can use a second hand one from a second hand key on eBay (usually about £5).

With the CL chip, you will know if it doesn't work because when you press the buttons on the key in the sequence, it will just fail. Need a new chip but as I said, that means going to Peugeot and getting raped for one.
The pre multiplex 206 keys work and so do the very late 106 ones. The early 307 ones could as they share a very similar system but I'm yet to try this!