The Swiss National Bank recalled its eighth-series banknotes as of 30 April 2021.

The banknotes from the eighth series thereby lost their status as legal tender and can no longer be used as payment. However, they retain their value and may be exchanged in person for an unlimited period at the SNB counters in Berne and Zurich or at an SNB agency. They can also be sent to the SNB by post. (Certain agencies have limits on such exchanges.)

Public cash offices of the Confederation (SBB/CFF, Swiss Post), will continue to accept eighth-series banknotes until 30 October 2021.

Source:

Swiss National Bank