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.
Banknotes of the Swiss franc
Switzerland is unusual among affluent countries in that it expires its banknotes; the Swiss National Bank has declared several older series of banknotes to be no longer legal tender some time after introducing newer series. Notes from these "recalled" series can be exchanged for still-valid notes at the National Bank for up to 20 years after the date of recall, after which the notes lose all value. When recalled series become valueless, the National Bank transfers an amount of money equal to the sum of the now-worthless notes to a state-run last-resort disaster insurance fund, the Swiss Fund for Aid in Cases of Uninsurable Damage by Natural Forces. The most recently recalled series of banknotes, the sixth series, was recalled on 1 May 2000 and will expire on 1 May 2020. The Swiss Federal Council (executive cabinet) and National Bank have proposed to remove this twenty-year time limit for the sixth series as well as any future recalled series; as of mid-2018, this proposal remains in the draft bill stage.