Since Poland’s accession to the European Union, European law has become part of the legal system in force in Poland. Treaties and regulations are directly applicable, whereas directives and recommendations require implementation into Polish law. Polish courts are obliged to apply and interpret European company law and to interpret Polish company law in such a way that it complies with European law. If in doubt as to the interpretation of European company law, the courts may — and in some cases must — refer a question to the Court of Justice of the European Union for a preliminary ruling. The judgment of the Court is binding on the courts of all Member States. Polish companies may conduct business activity in another Member State and foreign companies may conduct business activity in Poland. Companies of the Member States may conduct their business activities by establishing companies under the provisions of European law, e. g., Societas Europaea. Societas Europaea (SE) is a European public limited company whose capital is divided into shares. The European company is a cross-border company that can operate in the EU countries alongside national public limited companies. The autonomous status of an SE in relation to domestic public limited-liability companies is determined by two circumstances: first, the SE’s personal statute (lex societatis), legal capacity and other elements of the SE’s legal status are determined by the regulation either directly or by indicating the ways to fill in the gaps in the regulation; second, the content of the regulation, which contains specific rules for the creation and operation of the SE, distinguishes it from national public limited-liability companies. European law also influences the legal situation of Russian citizens and companies who are partners (shareholders) of a company registered in a Member State.