For 47 years the United Kingdom has been part of the European Union (EU) and its predecessor, the European Communities. One of the main aims of the EU is to establish an internal market, an area without internal frontiers where free movement of goods, persons, services, and capital is secured amongst its Member States. To fulfil this important objective, a customs union regulating tariff and non-tariff barriers and covering all trade in goods between the EU Member States was created. As such, free movement of goods across the EU had been facilitated by prohibiting the Member States from introducing customs duties and charges having equivalent effect, restricting national discriminative internal taxation and protectionist fiscal measures and outlawing domestic quantitative and equivalent restrictions on trade in goods. All possible Treaty and case law derogations and exceptions to these barriers are strictly limited and narrow. In June 2016 the United Kingdom has voted to leave the European Union and after several years of negotiations the UK has left the EU on 31st January 2020. Following a brief transition period and a rather strenuous approval of the UK-EU Trade and Cooperation Agreement, the free movement of goods regime between the UK and EU has ceased to exist on 1 January 2021. Notwithstanding the temporarily ongoing easement of certain border control measures, businesses are now expected to face full movement of goods control and compliance by the end of 2024. Drawing upon the academic commentary, this chapter discusses the post-Brexit rules on trade in goods between the United Kingdom and the European Union under the UK-EU Trade and Cooperation Agreement. It examines how the trade in goods regime has changed following the UK’s departure from the EU, analyses the status quo and ongoing trends, outlines existing issues and difficulties, and considers the possible developments and further cooperation in this field.