Smartphones are now a ubiquitous part of daily life for adolescents in the UK, who use their phones for a multitude of reasons beyond calling or texting. To date, there has been little qualitative research conducted with adolescent smartphone users about their experiences of smartphone use, particularly problematic or excessive use. This study directly explores the topics of problematic use and smartphone etiquette with 13 British adolescents aged 16 – 18 years across three focus group discussions. An inductive thematic analysis resulted in the development of four themes relating to users’ experiences: The Comfort Bubble; Digital Native Etiquette; The Extended Self and Defining Dependency. These themes encompass the different drives underlying potentially excessive or anti-social smartphone use and how young people seek to minimize these risks by monitoring both their own and others’ smartphone phone use. The findings of this study demonstrate the complexity of disentangling functional and enjoyable smartphone use from problematic use in an era where smartphones are embedded so deeply in modern life. Implications of these findings are discussed in terms of potential future measures of problematic smartphone use and ways of promoting education about healthy smartphone use using some of the strategies suggested by the young people in this study.