Term‐time employment among Britain’s undergraduates is a growing phenomenon but it has received scant attention from government and policy makers. Although there are numerous studies on the subject, few have explored the impact of term‐time employment on students’ actual attainment and those that have are limited. This article attempts to fill that gap. Using data derived from 1000 students in six UK universities, it quantifies the impact of students’ paid work on their actual marks and degree results, while controlling for their academic attainment on entry to higher education and other factors including their hours of work. It shows that irrespective of the university students attended, term‐time working had a detrimental effect on both their final year marks and their degree results. The more hours students worked, the greater the negative effect. Consequently, students working the average number of hours a week were a third less likely to get a good degree than an identical non‐working student. Some of the least qualified and poorest students are most adversely affected perpetuating existing inequalities in HE. The 2006/07 changes to student finances may help some of them, but term‐time employment is likely to remain part of the HE landscape.