Business travel contributes to significant greenhouse gas emissions, and there is a need for measures that reduce the demand for trips made with energy-intensive means of transport. In this study, a mobility service application (MSA) introduced in 13 Swedish organisations was tested and evaluated to facilitate booking and handling of business trips, in particular public transport. A before and after study consisting of surveys and interviews with employees at the organisations were conducted. The results show that the MSA was mostly used for regional and local public transport trips, and the users stated that the MSA made it easier to travel by public transport, although this particular result should be seen as tentative due to the small sample size. Three factors that influence the success of a new MSA as a means to increase sustainable business trips were identified: management control and proactiveness; perceived improvement of intervention; functions and technical sufficiency. The results also highlight the need to establish organisational conditions that facilitate sustainable business travel, such as coherent travel policy, accessibility to sustainable modes of transport, and a culture that encourages environmentally friendly behaviour. The study suggests improvements that can be made to similar interventions and strategies that can be introduced to promote sustainable business travel.