It’s not an edge case. Zone B begins at the inner S-Bahn-Ring. There’s a lot of destinations that are reachable via U-Bahn and Bus/Tram outside the inner ring.

It’s not an edge case. Zone B begins at the inner S-Bahn-Ring. There’s a lot of destinations that are reachable via U-Bahn and Bus/Tram outside the inner ring. It’s so common to travel outside zone A that you can’t even buy a zone A ticket, it’s always A+B Keep in mind that “city” is only available for 120 cities in germany in the first place.