evidence: As an EU Member State, the United Kingdom was part of the EU’s Customs Union and part of the EU Single Market. The Single Market applies to countries in the European Economic Area (EEA), which includes the EU as well as Iceland, Liechtenstein and Norway. Leaving the EU entailed a departure from each of these for the United Kingdom, but differentially for Great Britain and for Northern Ireland. Hence, Great Britain left both the Customs Union and the Single Market. In contrast, Northern Ireland remains in the EU’s Single Market for goods, but not for services, and while not part of the Customs Union, remains part of the EU’s common customs territory. The departure from the Customs Union and the Single Market has impacted the degree of market access between the United Kingdom and the EU (and the United Kingdom and third countries) in different ways. The changes in market access and the increase in firms’ costs thus involve a combination of tariff barriers, administrative barriers and regulatory barriers. [...] The United Kingdom comprises Great Britain (England, Scotland and Wales) plus Northern Ireland. Northern Ireland has remained in the EU’s Single Market for goods.