The growth of transnational education has been a major focus of attention for the UK sector since 2010. During a period when international student recruitment has stagnated, transnational education (TNE) has been widely seen as an alternative way of diversifying revenue and building international profile for universities. The UK presently dominates the global TNE market. In 2017/2018, approximately 700,000 students were studying for UK higher education qualifications in their own country -- more than twice the number of international (non-European Union) students who travelled to the UK to study. Despite the interest in TNE and the growth in offshore enrolments, there has been growing scepticism about the net economic benefits of TNE and the sustainability of TNE models. This article reviews the drivers of TNE activity and concludes the high-tide mark for UK universities has been passed and that TNE may be entering a period of decline.