On application, all lenders will do multiple searches of residence and identity and if the credit addresses differ from the electoral roll they are going to ask why and they will want further proof of where you are living at a particular address and this proof will be required through national providers communications such as a bank statement or credit card statement, utility provider or landline bill dated within the last 3 months.

Assuming you have these under the right addresses then I doubt the lenders will ask too many questions but if you have had several addresses in the last couple of years then it could get sticky. Best advice would be that if you are buying a house then you may as well change all your address details to your current address as this will boost your application score, even if you are then going to need to change again shortly after for the house move.

I doubt having accounts registered to your parents address serves any benefit or purpose if you no longer live there so you would be best advised to move everything to your new address

My credit is all registered to one address (my parents). However I feature on the electoral at a different address where I reside. I can easily change my credit to my current address where I feature on the electoral roll. However I would like to know if there is an optimum amount of time that your credit address should match where you are listed on the electoral roll for credit check purposes (i.e. to obtain a mortgage).