On 24 December 2021, the Supreme Court ruled that the way in which the box 3 levy has been designed since the year 2017 violates both the prohibition of discrimination (art. 14 ECHR) and the right to peaceful enjoyment of possessions (art. 1 FP ECHR). Legal redress was provided through an alternative return calculation based on the so called fixed-rate savings option.
However, on 6 June 2024, the Supreme Court ruled that this legal redress also fails the test. In particular, the return calculation on possessions other than savings is still discriminatory. The difference in tax treatment between successful and less successful investors is still significant, without this being sufficiently justified. The Supreme Court even took this one step further and ruled that the above likewise applies to the Box 3 Bridging Act, as the latter is based on virtually the same principles.

On 20 December 2024, a number of other judgments addressing the box 3 legal redress was pronounced. The Supreme Court took this opportunity to clarify the return calculation on dwellings in box 3. Following these judgments, the government has decided to introduce a rebuttal scheme in box 3. To this end, a bill was introduced in the House of Representatives on 14 March 2025.

Next, the bill on the Box 3 Actual Return Act was submitted to the House of Representatives.on 19 May 2025. This bill provides for annual taxation of actual returns, based on a combination of a capital gains tax (immovable properties and shares in start-ups) and a capital gains tax (other assets and liabilities), effective from 2028.