The ZVV system is zonal in nature, with fares for individual journeys set by the zones the journey passes through. Not all zones are equal, with higher fares being charged for travel in some zones. The whole of the city of Zürich is within a single zone, but as some VBZ routes travel beyond the city boundaries, a multi-zone ticket is needed for some VBZ journeys. Both single journey and day tickets are available, as are a number of passes with longer validities.