Private banks see great potential in digital technologies for engaging with clients. Both practitioners and researchers believe that digital technologies, such as mobile applications, increase transparency in the advisory process and consequently raise trust, satisfaction and customer loyalty. This study proposes 5 design requirements (DR) for developing trust in a mobile financial advisory service. A first prototype was designed following the proposed DR. In addition, we conduct an experimental evaluation with 34 participants and compare the prototype with email communication. The findings provide mixed results on how a mobile application, designed according to the proposed DR, could increase trust and intention to use. With regard to overall satisfaction, the app was favored over email communication.