<p>This research investigates why undergraduates at a widening-participation institution in the UK fail to submit assignments and whether the reasons differ by ethnicity. This addresses two issues current in higher education: student attrition, which has been shown to correlate positively with non-submission of assignments; and the ‘awarding gap’ between Black and White students: the difference in the percentage of ‘good’ degrees (first or upper-second class) awarded to each ethnic group. Previous research has identified the problem of non-submission and the demographic profile of those more likely not to submit assignments. However, very few studies have explored the reasons why. Eighty-eight students provided their reasons for not submitting an assignment through an open-ended question within a survey. Thematic analysis revealed that students’ reasons fell into three categories: situational, dispositional and institutional. Two-thirds of the reasons for non-submission were situational, including health, mental health and family and caring responsibilities. As many situational factors could be accommodated by students applying for extensions and mitigating circumstances, institutions should explore why often students do not make use of these processes. Another frequently cited factor was the timing of assignment deadlines, which is of interest to those with responsibility for planning the student workload. Comparing ethnicities, White students were significantly more likely to report health-related reasons for non-submission than their Black counterparts. Further research is needed to explore this finding.</p>