Information in SIS is shared among the institutions of countries participating in the
Schengen Agreement Application Convention (SAAC). The five original participating countries were France, Germany, Belgium, the Netherlands, and Luxembourg. Twenty-two additional countries joined the system since its creation: Spain, Portugal, Italy, Austria, Greece, Finland, Sweden, Switzerland, Denmark, Iceland, Norway, Estonia, the Czech Republic, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, Slovenia, Liechtenstein, Croatia, Bulgaria and Romania. Among the current participants, Iceland, Liechtenstein, Norway, and Switzerland are members of the
European Free Trade Association but not of the
European Union. Although Ireland and the United Kingdom operate a
Common Travel Area and had not signed the Schengen Agreement Application Convention (when the United Kingdom was still an EU member), they had the right to take part in Schengen co-operation under the terms of the
Treaty of Amsterdam. Ireland joined the law enforcement aspect on 1 January 2021 and has "full operational capacity" since March 2021. As a consequence of
Brexit, the UK lost access to the system on 31 December 2020. (UK law enforcement did 571 million searches in the database in 2019 alone) and does not expect to regain any access before 2027 at the earliest. == Introduction ==