Liechtenstein's historical customs union with Austria was dissolved in 1919. A customs treaty was signed in 1923 and since its entering into force in 1924, Liechtenstein and Switzerland have been in a customs union with each other and as such the borders between the two countries are open. The German village Büsingen am Hochrhein and the Italian village Campione d'Italia also form part of this customs union (the latter albeit in a "de facto" manner), which is often referred to as the "Swiss customs area".