The 2010 Double Taxation Agreement (DBA) between Germany and the United Kingdom is part of both the German legal system and the British legal system. It applies regardless of whether the UK is a member of the EU or not. This means that, even after Brexit, the DBA will continue to prevent double taxation of income by the two states and will continue to facilitate administrative cooperation in tax matters. In certain circumstances, a person may be subject to simultaneous tax in two jurisdictions if he is employed in one country but spends time in another country. A country-to-country double taxation agreement can be invoked in many cross-border situations to exempt a source of income from taxation in a given country. However, not all double taxation agreements are the same and there is a need to ensure that contractual provisions can apply to individual workers. The European Commission will also provide comprehensive information on these and related issues, including customs duties, excise duties (indirect taxes), rules of origin and VAT. The European Commission has launched an online consultation to identify public and business views on the possibility of setting up a mechanism to eliminate double taxation in individual cases. The residency clause of a double taxation agreement is, as a rule, Article 4, which refers to a person who works outside the country in which he or she is considered a resident within the meaning of the treaty (the resident). It is possible, under national law, to reside simultaneously in several countries and Article 4 helps to determine which of the two countries covered by the treaty will have primary tax duties on certain types of income, namely the country that is the first to tax income and the country that is required to authorize either an overseas tax credit suffered , an exemption from these incomes. This guide applies to double taxation conventions, as they apply to income from work, but not to international social security conventions (see guide to social security agreements).
Should there be a Brexit without a deal, the customs administration will treat the UK like any other third country that does not have a specific customs agreement with the EU.