The Member States finally decided not to sign the protocol next to the Croatian accession treaty, but as a single document. The European Council proposed a draft protocol on this subject and adopted it by the European Parliament in April 2012.  16 May was followed by an intergovernmental conference and the protocol was signed by all EU states between that date and 13 June 2012.  The protocol was due to enter into force on 1 July 2013, provided that all Member States had ratified it by then, but it did not enter into force until 1 December 2014.  The United Kingdom is also not part of the borderless Schengen area. The agreement, which allows travel to the EU without a visa or passport, does not extend over the English Channel (or the Irish Sea). Neither the United Kingdom nor Ireland is part of the Schengen area. In accordance with Protocol 19 of the Lisbon Treaty, the UK has three months to respond to any EU proposal under the Schengen Agreement. If it does not inform the Council that it wants to unsubscribe, it will automatically be bound by the new judgment. All Member States, with the exception of Denmark, have adopted the euro or are legally obliged to do so. The 1992 Maastricht Treaty contained protocols on the United Kingdom and Denmark, which gave them exemptions with the right to decide whether and when they would join the euro. Denmark then informed the Council of the European Communities of its decision to leave the euro, which was incorporated into the 1992 Edinburgh Agreement, a Council decision adopted by Danish referendum after the initial rejection of the Maastricht Treaty in 1992.
The aim of the agreement was to support its approval in a second referendum, which it did. The Danish decision to opt out was then formalised under the Lisbon Treaty as part of an amended protocol. The 1992 Edinburgh Convention guaranteed Denmark that they would not be obliged to join the Western European Union, which was responsible for defence. In addition, the agreement provided that Denmark would not participate in the discussions or be linked to EU decisions with defence implications.