In 1999, the United Kingdom formally requested participation in certain provisions of the Schengen acquis – Title III on police security and judicial cooperation – in 1999, and this request was adopted by the Council of the European Union on 29 May 2000.  The UK`s formal participation in previously approved areas of cooperation was brought into effect by a 2004 Council decision that came into force on 1 January 2005.  Although the United Kingdom was not part of the Schengen area, it has always used the Schengen information system, a government database used by European countries to store and disseminate information on individuals and goods. This has allowed the UK to exchange information with countries that are part of the Schengen Agreement, often to connect to legal proceedings.  In 2020, the United Kingdom has declared that it will withdraw from these agreements at the end of its transition period. There have been or have there been projects for Lithuania-Russia, Poland-Belarus, Bulgaria-Serbia and Bulgaria-Northern Macedonia on cross-border transport.  The agreement between Poland and Belarus was due to enter into force in 2012, but was delayed by Belarus without a transposition date (october 2012).  Authorizations are issued for a period of one to five years and allow you to stay in the border area for up to three months. Permissions may only be granted to legitimate residents of the border area who have been in the border area for at least one year (or more if provided for in the bilateral agreement). Applicants must prove that they have legitimate reasons for frequently crossing a land border under the local border transportation system.
Schengen states must maintain a central register of authorisations issued and allow other Schengen states immediate access to relevant data. If the EU adopts a new legislation important to the Dublin Schengen acquis, Switzerland will have to decide whether it wants to adopt it, in accordance with Switzerland`s direct parliamentary and democratic processes. Since the signing of the agreements in 2004, the EU has notified Switzerland of more than 250 other developments in the Schengen acquis.