Box 3 tax is calculated on a deemed (fictitious) return, not your actual gains. The Belastingdienst assigns a fixed rate of return to your savings (1.28% provisional for 2026) and a higher rate to investments (6.00%, finalised for 2026). Those rates are applied to your taxable wealth — total assets minus the €59,357 tax-free allowance — and 36% tax is levied on the resulting deemed income. You owe this tax regardless of whether your portfolio grew or declined during the year. From the 2025 aangifte you can alternatively submit your actual return; the Belastingdienst will apply whichever is lower.

The heffingvrij vermogen is €59,357 per person for 2026. Fiscal partners can combine their allowances, giving a household threshold of €118,714. Wealth below this threshold is not taxed at all. The exact figure is set annually by the Belastingdienst and may be slightly adjusted for inflation each year.

Yes. ETFs and other investments held in a regular brokerage account are classified under the “investments and other assets” category in Box 3. In 2026 this carries a deemed return of 6.00% (finalised), taxed at 36%. You pay this tax every year based on your portfolio value on 1 January — it does not matter whether you bought, sold, or held throughout the year. From the 2025 aangifte you can submit your actual return as an alternative if it would result in lower tax.

Yes. Dutch tax residents are taxed on worldwide assets in Box 3. This includes foreign bank accounts (treated as bank savings, lower rate), foreign brokers such as IBKR Ireland and Trading 212 (treated as investments, higher rate), foreign crypto exchanges, and Revolut or Wise balances. If your foreign bank or broker does not automatically report to the Belastingdienst, you are responsible for declaring the balance yourself in your aangifte. Undeclared foreign assets are treated as tax evasion, not an oversight.

From 1 January 2025 you can no longer choose partiële buitenlandse belastingplicht (partial non-resident status) for Box 3 purposes. Those using the 30% ruling before 1 January 2024 retain the partial non-resident status through the end of 2026 only. From 2027, all Dutch tax residents — including 30% ruling holders — are taxed on worldwide assets in Box 3 without exception.

Bank savings carry a lower deemed return (1.28% provisional for 2026) than investments (6.00%), so cash at a bank is taxed less heavily. However, the deemed return for investments approximates long-term market returns — investors who actually outperform the deemed rate get tax-efficient upside. Holding excess cash purely for tax reasons usually destroys more wealth in real terms than the tax saving is worth. The better question is: what does your actual financial plan require?

From the 2025 aangifte (filed in 2026), yes. The Belastingdienst now offers a tegenbewijsregeling: you can submit your werkelijk rendement — actual dividends, interest received, and the change in portfolio value over the year — and the tax office will apply whichever method produces lower tax. For the years 2017–2024, the Belastingdienst is sending letters to eligible taxpayers about submitting actual returns under the Kerstarrest massaal bezwaar process and transitional rules. A full statutory actual-return system (Wet werkelijk rendement box 3) passed the Tweede Kamer in February 2026 and is awaiting the Eerste Kamer, with a target start date of 1 January 2028.

Yes. The main legal strategies are: (1) filing with a fiscal partner to double your tax-free allowance to €118,714; (2) maxing out lijfrente contributions to move assets into Box 1; (3) using certified green investments exempt up to €26,715 per person / €53,430 for fiscal partners (note: this exemption is being phased out and scrapped entirely by 2028); (4) keeping idle cash in a bank account rather than your brokerage; (5) submitting your actual return via the tegenbewijsregeling in years when your portfolio underperformed the deemed rate; (6) being mindful of large cash balances around 1 January while respecting the anti-arbitrage rule.

Box 1 covers income from employment and your primary home, taxed at progressive rates up to 49.5%. Box 2 covers dividends and gains from a substantial shareholding (5%+ in a company), taxed at 24.5–33%. Box 3 covers wealth from savings and investments, taxed at 36% on a deemed return — not on actual gains.

Box 3 currently taxes a deemed return — a fixed percentage the government assumes you earned on your assets — not your actual realised gains or dividends. From the 2025 aangifte you can submit your actual return as an alternative and pay whichever is lower. A fully statutory actual-return system (Wet werkelijk rendement box 3) passed the Tweede Kamer in February 2026 and is targeted for introduction in 2028.

Your Box 3 balance is valued on 1 January of each tax year (the peildatum). Only the assets you hold on that single date determine your tax base for the entire year — there is no averaging across the year. Large temporary cash inflows arriving in late December (bonuses, property sale proceeds) can inflate your bill if they have not yet been redeployed.

Box 3 applies to Dutch tax residents. Because the peildatum is 1 January, emigrating mid-year still means you owe Box 3 for that full tax year — you were a resident on 1 January. Timing your departure to very early January removes one full year of liability. Tax treaties between the Netherlands and other countries generally do not eliminate Box 3, as they are primarily designed around income taxes rather than wealth taxes. Confirm your exact situation with a belastingadviseur before emigrating.