This study considers the burden placed on participants, subjectively and objectively, when asked to use a mobile app to scan shopping receipts. The existing literature on respondent burden is reviewed to present a framework of seven factors that affect burden, and this research demonstrates how these may be used to identify potential predictors of burden. Such an approach, together with the findings of this paper, have potential implications when applied to a number of emerging research contexts involving in-the-moment and repeated data collection. Data from both the Understanding Society Spending Study, a shopping receipt scanning study using respondents mobile phones, and the ninth wave of the Understanding Society Innovation Panel were used. Evidence was found to suggest that subjective perceptions of burden may not be strongly correlated with the actual objective burden faced. There were no systematic trends in subjective burden throughout the course of the study, though, as respondents completed more of the repeated tasks in the study, the objective burden per task did decrease. In terms of predictors of burden hypothetical willingness to complete the task was predictive of lower subjective burden. Older and female respondents also took longer to complete individual tasks in the study.