Legal tender
The Swiss franc is also the currency used for administrative and accounting purposes by most of the numerous international organisations that are headquartered in Switzerland.
Hard currency
The Swiss franc (CHF) has long been considered a hard currency, and in fact was the last paper currency in the world to terminate its convertibility to gold. In the summer of 2011, the European sovereign debt crisis led to rapid flows out of the euro and into the franc by those seeking hard currency, causing the latter to appreciate rapidly. On September 6, 2011, the Swiss National Bank announced that it would buy an "unlimited" number of euros to fix an exchange rate at 1.00 EUR = 1.20 CHF, to protect its trade. This action temporarily eliminated the franc's hard currency advantage over the euro but was abandoned in January 2015.