Buying into the pension fund
Many Swiss have a pension gap because they have not made any or enough payments into their pension fund (Berufliche Vorsorge).
Making purchases into the pension fund can close these gaps and save taxes at the same time, because subsequent purchases into the pension fund can be deducted from taxable income in full. The maximum possible purchase amount can be found on the pension fund statement.
But be careful: Before paying in, check the situation of your pension fund, because if there is a threat of restructuring or partial liquidation, you will also be paying for this and might lose some money.