I called the Bundesamt für Migration and the stupid woman had no clue of anything. She kept on asking: Do you already have a resitence permit and a work permit in London?

Anyway, she couldn't help me.
We are finally moving back to the UK (London).
We only keep some personal things. First I have to look for a property before my Mom's BF will put the few boxes across the canal.
Does anybody know how the costum regulation works?
As I know we have to list everything exactly in german and english.
But do we have to seal everythig, like a few years ago?
It would be lovely if someone could tell me how it works or where I get all the right infos.
Couldn't find anything at ezv.admin.ch