This paper uses Universities and Colleges Admissions Service (UCAS) data on applications and entries to full-time undergraduate courses to examine the changing flows of students across the boundaries of the four countries of the United Kingdom (UK), over a period (1996-2010) that embraces parliamentary devolution. It asks whether the emergence of more distinct administrative systems of higher education, following devolution, is reflected in more distinct social systems as reflected in reduced cross-border flows of students. It reveals a declining tendency for UK applicants to apply to, and enter, higher education in another UK country. This trend is partly attributable to devolution and to consequent changes such as differential fees. However the detailed patterns vary widely across the countries of the UK, across categories of student and across types of institution and programme. (Contains 7 tables.)