When the United Kingdom government announced a disposable vapes ban from the 1st June 2025 in response to a rise in youth vaping, it was not clear how it would impact adults in the United Kingdom who used disposable vapes. In this qualitative study, we recruited and interviewed 22 young adults (n = 20 aged 18-22 years, n = 2 aged 29-30 years) residing in the United Kingdom who regularly used disposable vapes and self-reported either: having never smoked cigarettes, having previously smoked, or currently smoking. In online semi-structured interviews, we explored participants' experiences of vaping and smoking, what they might do once disposable vapes were banned, and how they thought the ban would impact other people. The data was analysed using reflexive thematic analysis. Three themes were constructed relating to our research aims: "reasons for using disposable vapes", "personal impacts of the ban", and "wider impacts of the ban". Most of our sample were female psychology students recruited via the University of Bristol. Recruitment primarily occurred in and around the University of Bristol campus and via the website. Participants were largely supportive of the ban due to the rise in disposable vape use among young people. Many young adults said they would switch to reusable/rechargeable vapes after the ban while others said they would stop vaping. Some participants (including some who had never regularly smoked before) said they might/would smoke cigarettes instead. Some suggested the ban would reduce current illegal sales of disposable vapes and others thought it may increase them. This study suggests the ban could have intended and unintended consequences for young adults who use disposable vapes, including increasing the use of cigarettes among some of these individuals. The findings highlight areas for future observational studies investigating the impacts of the ban and could aid identification of mitigating factors of unintended consequences.