We moved in November. We bank with three banks, and with two of them it's taken forever for them to change the address. We've been to the banks with proof of our new address, but my inlaws still get loan and bank statements occassionally, and it has been a pain for my husband to update his credit report's address.
We finally got the electoral register to list my husband (not me yet as I don't have citizenship), but it still lists the previous tenant. She's back in India. We're fixing that according to the instructions.
When I call the council, depending on which department I talk to, they either have our name, a previous tenant's name, or our landlord's wife's maiden name. We've tried to iron things out, but it seems nothing's simple.
But totally expecting non-related people to collect your post is bang out of order.