Box 3 - current developments

On 24 December 2021, the Supreme Court ruled that the way in which box 3 taxation is structured since 2017 is contrary to both the prohibition of discrimination (Article 14 of the ECHR) and the right to peaceful enjoyment of property (Article 1 of Protocol 1 to the ECHR). The legislator offered legal redress by means of an alternative calculation of returns based on the so-called flat-rate savings variant.

On 6 June 2024, however, the Supreme Court ruled that this legal redress also fails to stand up to scrutiny. In particular, the calculation of returns on other assets is still discriminatory. A significant difference in tax treatment between successful and less successful investors continues to exist, without sufficient justification. This also applies to the Box 3 Bridging Act, as it is based on the same principles. In response, the legislator introduced a retroactive rebuttal scheme based on actual returns in box 3.

Then, the bill introducing the Box 3 Actual Return Act was submitted to Parliament in May 2025 and adopted by the House of Representatives on 12 February 2026. The bill is expected to provide for an annual tax on actual returns as of 2028, based on a combination of capital gains tax (real estate and shares in start-ups) and capital growth tax (other assets and debts). However, the coalition agreement concluded on 30 January 2026 between D66, VVD and CDA shows that the government plans to switch to a full capital gains tax over time.