On December 15 of last year, the European Council of the 27 remaining Member States (EU-27 hereinafter) concluded that sufficient progress had been made in the first phase of the Brexit negotiations that started in June 2017. This edition of the World Economy Brief summarizes the results of the first phase, which dealt with important matters regarding the United Kingdom's exit from the European Union per se, namely (1) the rights of citizens of the EU-27 residing in the UK and vice versa, (2) the border between Ireland, a remaining member state, and Northern Ireland, a part of the UK and (3) the settlement of financial commitments made to each other. It then explains the two main topics of the second-phase negotiations: a possible transition period and the form of the post-Brexit relationship between the EU and the UK.