Although not a member of the EU, Switzerland, because of its position at the heart of Europe, maintains strong economic and social relations with many Schengen states and is part of the European Free Trade Association (EFTA) with Iceland, Norway and Liechtenstein (other third countries within the Schengen area). Switzerland became an integral part of the Schengen area after signing the agreement on 26 October 2004 and beginning to implement it on 12 December 2008. Not only are EU nationals visa-free, but they also have the right to enter and stay without a visa within the limits of the other. However, this freedom of movement may, in rare cases, be restricted, as stipulated in the EU treaties. The concept of free movement was originally intended to allow the European labour force to settle freely in any EU Member State, but the abolition of border controls within the EU remained behind it. A breakthrough took place in 1985, when cooperation between governments led to the signing in 1990 of the agreement on the phasing out of common border controls in Schengen (a small village in Luxembourg), followed by the signing of the agreement to implement the convention in 1990. Implementation of the Schengen Agreements began in 1995, with the participation of seven EU Member States. Developments from the Intergovernmental Initiative, which were triggered by the Schengen Agreements, have now been incorporated into EU rules. Today, the Schengen area covers most EU Member States, with the exception of Bulgaria, Croatia, Cyprus, Ireland and Romania. However, Bulgaria, Croatia and Romania are currently in the process of joining the Schengen area. From third countries, Iceland, Norway, Switzerland and Liechtenstein have joined the Schengen area. The German Ministry of the Interior will extend migration controls at the borders with Austria and Denmark by six months.

Denmark, Austria and France have also announced their intention to extend border controls. (12.10.2018) The Schengen Agreement includes two separate agreements that were ratified in 1985 and 1990 respectively. Between them, they abolished border controls and greatly facilitated transit through Europe. The two individual agreements stipulate that, although Andorra has not yet signed the Schengen Agreement, there is no control at its borders with neighbouring Spain and France. San Marino has also not signed the Schengen Agreement, but there are no border controls with its only neighbour, Italy. Further information on internal border controls is available in the Judgment of the European Court of Justice in C-444/17 (Arib) and in the COM Commission Reports (2010) 554 on internal borders, COM (2012) 230 on the functioning of the Schengen area and COM (2013) 326 on the functioning of the Schengen area. 12 December 2008 (Land Borders), 29 March 2009 (Air Borders) Europe owes its open borders to the Schengen Agreements, which allow cooperation and freedom of movement in 22 of the 28 EU Member States.