This chapter covers the institutional and procedural rules of the EU. When a country joins the EU, adaptations need to be made to these rules to ensure this country’s equal representation in EU institutions (European Parliament, Council, Commission, Court of Justice) and other bodies and the good functioning of decision-making procedures (such as voting rights, official languages and other procedural rules) as well as elections to the European Parliament. EU rules in this chapter do not affect the internal organisation of a Member State, but acceding countries need to ensure that they are able to participate fully in EU decision-making by setting up the necessary bodies and mechanisms at home and by electing or appointing well-prepared representatives to the EU institutions. After concluding the accession negotiations, specific rules for the interim period until accession ensure a smooth integration of the country into EU structures: an information and consultation procedure is put in place and, once the Accession Treaty is signed, the acceding country is granted active observer status in the European Parliament and Council as well as in Commission committees.