[quote=@Vertigo]
Hmm, would it be okay to have a character who's originally born in one of the inner districts, but ended up working in the 10th later on? Death of wealthy parents and the loss of her own wealth, a rank that allows her to travel or some other reason? If not, I can definitely have her be born in the 10th as well.
[/quote]

Rank II cleaners and above can travel between districts (at least temporarily), so that's fine. Primarily, it's civilians that can't go between.

Generally, each district requires you to buy a citizenship unless you're born there, cleaner exemption withstanding. Most people won't be able to afford it.

You can go either way. Buying a 10th district citizenship (not worth much), being connected in politics, cleaner rank travel, etc.