yeah, I've just had a talk with my credit expert (he really is one he can clean up anyone's credit file however terrible) and he says that addresses aren't officially blacklisted, but if you unlink yourself from an address then you drop any bad score from there on your file. However, lots of companies unnofficially share info and may do their best to wreck you up if they don't like you. But as Juno says in this case they're just trying to scare you. Go for the £100 a month deal!