The United Nations Educational, Scientific and Cultural Organization (UNESCO) collect and publish the number of UK students studying wholly overseas. Tertiary education is defined as International Standard Classification of Education levels 5-8. Statistics on mobile UK students studying abroad in 2016 and 2017 have been provided in the table. Data for 2018 has still to be published by UNESCO.
UK DOMICILED STUDENTS STUDYING ABROAD 2016 to 2017
Number of UK students studying tertiary education programmes abroad
Source: UNESCO, internationally mobile tertiary students studying abroad (2016 to 2017), data available at http://data.uis.unesco.org/.
In addition, ERASMUS collect and publish further information on the number of students studying overseas as part of their studies at their UK university, available at http://ec.europa.eu/programmes/erasmus-plus/about/statistics_en.