As described here, in the summer of 2025 a form can be filled in by taxpayers whose actual return was lower than the fictitious return in a given year. However, this must be specified and supported with documentation.

The actual return consists of the actual income on your box 3 assets. For instance, interest received on a bank account or loan, dividend income, capital gains and losses on e.g. shares or real estate, rental income, etc. The Supreme Court ruled that expenses will not be deductible, with the exception of interest on debts in box 3. Furthermore, both realised and unrealised gain should be included in the levy, e.g. a decrease in the value of shares or an increase in the value of real estate. To determine the value of property, the WOZ value is used.

In most cases a reduction will not be possible if there is a substantial increase in the WOZ value of a second home or holiday home. This underlines the importance of objecting against the WOZ value if it is on the high side.