Swiss franc
The Swiss franc is the currency and legal tender of Switzerland and Liechtenstein and also legal tender in the Italian exclave of Campione d'Italia. Although not formally legal tender in the German exclave of Büsingen am Hochrhein (the sole legal currency is the euro), it is in wide daily use there; with many prices quoted in Swiss francs. The Swiss franc is the only version of the franc still issued in Europe.
Liechtenstein–Switzerland relations
At the request of Liechtenstein's government in 1919, Switzerland safeguards Liechtenstein's interests and citizens abroad. The two form a common economic and monetary area (Liechtenstein has used the Swiss franc (since 1920) and has had a customs union (since 1924) with Switzerland with open borders (though both are now also party to the Schengen Agreement). The countries also have a common patent system. Switzerland is empowered to enter into treaties on Liechtenstein's behalf if Liechtenstein is not represented at the treaty negotiations; this power has most often been exercised with treaties involving customs duties or procedures.