A cash withdrawal is only possible if you are primarily self-employed and no longer subject to compulsory occupational pension insurance. You will be subject to a one-off tax at a reduced rate (in Vaud, one-fifth of the usual rate). The federal tax is also set at one-fifth of the usual rate. The pension fund is required to inform the Swiss Federal Tax Administration (FTA) that you have received this lump-sum payment. You must also inform your cantonal tax authority.