The chapter considers Brexit and the EU internal market. Barnard emphasizes the role that the UK played in creating the EU internal market and examines the view that its four freedoms—free movement of goods, services, capital, and people—are indivisible. The decision of the UK to leave the EU has paradoxically contributed to entrench the view that the four freedoms are indivisible. This reduces the possibility for the UK to maintain access to the EU single market after Brexit—a fact acknowledged even by the UK government. However, the EEA model might be the best solution for the UK post-Brexit, reflecting UK citizens’ demands, and also in the interest of the EU. Nevertheless, the withdrawal of the UK may strengthen protectionist trends within the EU. Moreover, Barnard emphasizes that Brexit poses challenges for the UK internal market, which the Great Repeal Bill will need to address.