change off address to bank /work/insurance company/subscriptions /pension provider [past and present]employer/hospital/doctor/school/freinds/
don't forget your car registration, driving license, car insurance..
first month is a costly one.. you'll get a water bill for the year ( unless it's on a meter ), need to buy a tv license, and quite a few other bits and pieces..
not to mention furnishing the place, buying all the kitchen stuff ( plates, cuttlery, cups, bowls, chip pan etc etc.. )