Urban mobility is experiencing a profound change. Mobility patterns are becoming more complex, and typical home–work–home travel is no longer the rule, as journeys tend to connect multiple points in a rather inconstant pattern. This has changed the approach to transport planning. Existing transportation planning and operation approaches have been focussed on the ability to identify and forecast typical home–work/school–home travel and subsequently plan the transport system accordingly. The traditional approach has been: Forecast - > plan - > deliver. New mobility patterns and mobility solutions are characterised by greater flexibility, taking advantage of the “sharing concept” and simultaneously providing solutions that have lower greenhouse gas (GHG) emissions. These dynamics and an evolving environment raise several new challenges at different levels, fostering the development of Mobility-as-a-Service (MaaS). This system transforms the physical transportation system into a commodity and takes advantage of the internet of things (IoT). However, the onset of MaaS solutions is anything but linear. Several business models have emerged, with different partners originating from different industries (e.g., technological, transport operators, infrastructure managers, etc.) developing their own solutions, often in competition with others. It is not unusual to find different MaaS solutions in the same city, which integrate different solutions. This paper intends to provide an analysis on the main challenges affecting mobility in general, and MaaS in particular, as well as the main business models used for delivering MaaS solutions. The paper uses a case study in Lisbon to illustrate some of the challenges.