Box 3 OWR: Actual Return in Practice
The Box 3 system is shifting toward taxation based on actual return: the real, nominal return on assets instead of a fictitious forfait. For the years 2017-2027, you can voluntarily report this via the OWR form (Opgaaf Werkelijk Rendement) to receive compensation if your actual return is lower than the forfaitary one. From 2028 onward, this becomes the main rule under a new legislative proposal.
What is “actual return”?
Actual return comprises the total nominal result on all Box 3 assets, including savings, investments, real estate, and loans. It includes both direct return (interest, rent, dividends; only interest costs on debts are deductible in the OWR phase) and indirect return (realized and unrealized price and value changes, such as WOZ mutations for properties).
The calculation is based on the entire Box 3 assets (no deduction of tax-free allowance), nominal per calendar year (no inflation adjustment), combining positive and negative results within that year. For OWR (2017-2027). From 2028 onwards, loss carryforward in box 3 is likely to be permitted, because the new system is based on a capital accrual tax in which negative returns qualify as offsettable box-3 losses.
Why this policy shift? (June 2024 rulings)
On June 6, 2024, the Supreme Court ruled in the D-Day judgments that the Box 3 levy, even under the Remediation Act and transitional legislation, remains in violation of the ECHR (property rights and non-discrimination) if the forfaitary return exceeds the actual return. Taxpayers must be able to prove their actual return is lower, after which only that lower return is taxed. This led to the Box 3 Counter-Evidence Act and the OWR form for years 2017-2027.
Actual Return Box 3 Act (from 2028)
The cabinet submitted the Actual Return Box 3 Act in May 2025. Main rule: capital accretion tax on direct and indirect nominal return at one rate (~36%), with tax-free income (€1,250-€1,800 per person) instead of tax-free assets. From 2028: loss carryover and broader cost deductions (incl. investment costs). Originally planned for 2026/2027, now earliest January 1, 2028 if adopted before March 2026. Final implementation depends on parliamentary process.
