I've used some of them before , I bought a van with no key , called one of these guys out who coded me a key and removed any old ones from working on the van, should anyone who might have the old keys just come along and try to steal it, if your not to happy to have them coming to your house arrange to drive to them, that way it's cheaper and it will be cheaper if you have one key already, that way they would need to drive around looking for the car, and they are not going to do that, these guys spend £1000's on there equipment and have to be registered to offer the service, yes there will be some that aren't, but most will,