In accordance with the Treaties, the decision was taken in agreement with the United Kingdom. Such an agreement was set out in a letter from the Permanent Representative of the United Kingdom to the European Union, Sir Tim Barrow, dated 22 March 2019. As of 1 January 2021, the United Kingdom is therefore no longer part of the internal market or customs union. Even if an agreement on the future relationship is reached by the end of the year, the relationship between the EU and the UK will change radically and will differ considerably from when the UK was a member of the internal market. Take, for example, the customs and tax formalities that are then necessary. Like the EU Member States, citizens and businesses in Germany and across the EU must prepare for these consequences of the end of the transitional period, whether or not an agreement is reached on the future partnership with Britain. Since its departure, the United Kingdom has had no say in the European institutions. British citizens are therefore also excluded from participation in European citizens` initiatives and do not have the right to vote in local elections in other EU countries, in elections to the European Parliament or in such elections. The rules applicable to citizens and businesses who wish to move, work or study in another country after the end of the transition period will depend to a large extent on the outcome of the ongoing negotiations on the future relationship between the European Union and the United Kingdom. . .