Schengen Area

The Schengen Area is an area comprising 26 European states that have officially abolished all passport and all other types of border control at their mutual borders. The area mostly functions as a single jurisdiction for international travel purposes, with a common visa policy. The area is named after the 1985 Schengen Agreement.

22 of the 28 EU member states participate in the Schengen Area. Of the six EU members that are not part of the Schengen Area, four—Bulgaria, Croatia, Cyprus, and Romania—are legally obliged to join the area in the future, while the other two—Ireland and the United Kingdom—maintain opt-outs. The four European Free Trade Association (EFTA) member states, Iceland, Liechtenstein, Norway, and Switzerland, are not members of the EU, but have signed agreements in association with the Schengen Agreement. Three European microstates—Monaco, San Marino, and the Vatican City—are de facto part of the Schengen Area.

The Schengen Area has a population of over 400 million people and an area of 4312099 km2. About 1.7 million people commute to work across a European border each day, and in some regions these people constitute up to a third of the workforce. Each year, there are 1.3 billion crossings of Schengen borders in total. 57 million crossings are due to transport of goods by road, with a value of €2.8 trillion each year. The decrease in the cost of trade due to Schengen varies from 0.42% to 1.59% depending on geography, trade partners, and other factors. Countries outside of the Schengen area also benefit. States in the Schengen Area have strengthened border controls with non-Schengen countries.

EU member states with opt-outs
Ireland and the United Kingdom were the only EU members which, prior to the 2004 enlargement, had not signed the Schengen Agreement. Both countries maintain a Common Travel Area with passport-free travel for their citizens between them and the three British Crown Dependencies of Jersey, Guernsey and the Isle of Man, that are outside the European Union. Gibraltar is a British Overseas Territory and is neither part of the Schengen Area nor the Common Travel Area.

The UK declined to sign up to the Schengen Agreement, one argument being that, for an island nation, frontier controls are a better and less intrusive way to prevent illegal immigration than other measures, such as identity cards, residence permits, and registration with the police, which are appropriate for countries with "extensive and permeable land borders". Ireland did not sign up to the Schengen Agreement because it "would not be in the interest of Ireland to have a situation where the common travel area with Britain would be ended and Ireland would impose both exit and entry controls on persons travelling between here and Britain and, in addition, on the land frontier".

When Schengen was subsumed into the EU by the Treaty of Amsterdam, Ireland and the UK obtained an opt-out from the part of the treaty which was to incorporate the Schengen rules (or acquis) into EU Law. Under the relevant protocol, Ireland and the United Kingdom may request to participate in aspects of the Schengen acquis but this is subject to the approval of the Schengen states.

The UK formally requested to participate in certain provisions of the Schengen acquis – Title III relating to Police Security and Judicial Cooperation – in 1999, and this request was approved by the Council of the European Union on 29 May 2000. The United Kingdom's formal participation in the previously approved areas of cooperation was put into effect by a 2004 Council decision that came into effect on 1 January 2005. Although the United Kingdom is not part of the Schengen passport-free area, it still uses the Schengen Information System, a governmental database used by European countries to store and disseminate information on individuals and property. This allows the UK to exchange information with countries that are a part of the Schengen agreement, often for the sake of liaising over law enforcement.

In contrast, while Ireland initially submitted a request to participate in the Schengen acquis in 2002, which was approved by the Council of the European Union, that decision has not yet been put into effect. In February 2010 the Irish Minister for Justice, in response to a parliamentary question, said that: "[t]he measures which will enable Ireland to meet its Schengen requirements are currently being progressed".

A previous 1999 report by the European Union Select Committee of the House of Lords recommended "full United Kingdom participation" in all the various four Titles of the Schengen Implementing Convention.

On 23 June 2016, the British electorate voted for the United Kingdom to leave the European Union, and on 27 March 2017 the United Kingdom formally requested such a withdrawal. It is not decided what the future state of Ireland will be, although it has been suggested that Ireland will stay in the Common Travel Area and not join the Schengen Area, because it wants to keep the lack of border control at its land border.