The Declaration of Actual Return is a form with which taxpayers with Box 3 assets (such as savings, investments and cryptocurrency) can report their genuinely achieved return for 2024 to the Dutch Tax Authority. The Tax Authority sends this form in 2026. Only after the form has been submitted does the final income tax assessment for 2024 follow. Completing this form is particularly worthwhile if your actual return is lower than the deemed return the Tax Authority would otherwise apply.