[duxup]

It's not mandatory as far as ... nobody is going to let you move.

It does mean that you'll get your old mail delivered to your old place forwarded to your new place while the other folks mailing you get their ducks in a row. And honestly I can't think of all the places that might mail me.

[Aachen]

Yeah I thought the topic was things you have to do to move, like registering in the new city and notifying the old country or so

[duxup]

Yeah I agree. But my point being it is a pretty tangential thing and also the first thing you think of in the US. The scale of "have to do" is really low, to the point that you start with something pretty easy and that's largely it as far as "official" moving activity.