I moved in August 2014 via a mutual exchange (so we swapped house's) and the person I swapped with still hasn't changed her address! I'm even getting car tax reminders from the DVLA! and I've just received my electoral register information and she's still bloody on it! So that means she hasn't told the local council she's now in their borough I know why as I receive daily debt letters for her but it's getting annoying!
I've tried telling them that she doesn't live there and I could give them her actual address but all i get is "she needs to tell us herself, until then we'll be sending people to you" 

It's been 5 bloody months I'm getting 5 letters a day from various debt companies even bills for a BT mobile for her ex partner who she said moved back to France!
It's getting annoying