Thanks for the replies. I didn't realise that my neighbour wouldn't be registered unless working for BG, I thought it was the person that was registered.
Bloody hell, that means they could send anyone to your door
Kev
A lot of engineers driving BG vehicles and working for BG can actually be contractors who are contracted to them five days a week or whatever, they might be Gas safe registered in their own right, why not just ask him ? I certainly would not be offended if any customer asked me for proof of registration or PLI , by the way I am not working for BG but have done in the past