We exploit changes in student funding policies across the four UK nations and the Republic of Ireland to conduct a natural experiment investigating the marginal effect of differing tuition fee levels on students' enrolment behaviour. Whilst previous international research suggests increases in fees suppress demand and disincentivise cross-border educational migration, some studies in North America and Germany find an element of inelasticity of demand. In the UK, various commentators have predicted marked shifts in student mobility in response to variation in tuition fee prices by country, trends expected to sharpen following substantial planned rises in tuition fees from 2012. After outlining tuition fee policies in the UK and Ireland, we analyse data on student enrolment destinations across the five countries for the period 2000-2010. We find little evidence to support the notion that student mobility is driven by economic "rationality". Enrolment rates have risen despite increases in tuition fees and there is a long-term trend for students to stay at home. Students seem not to be "pushed" out-of-country by higher fees, but may be discouraged from moving if fees are lower in-country. Student mobility within the UK and Ireland follows well-worn paths from and to specific countries and institutions. Finally, we consider the implications of our findings for student mobility in general and forthcoming changes to UK student funding policies in particular. (Contains 1 table, 7 figures, and 6 notes.)