Dutch Box 3 Tax Is Finally Changing: Here's the Full Story (2025–2028)
- 1 day ago
- 6 min read
Well — after years of court rulings, delays, and political back-and-forth — the Netherlands is finally changing it. The new system is set to take effect in 2028. But there's a lot happening in the meantime that's relevant right now.
Here's the full picture, from where we've been to where we're going.
First: What Box 3 Tax Actually Is
Box 3 is the Dutch wealth tax on income from savings and investments. It covers things like:
Savings accounts (above the tax-free threshold)
Investment portfolios (ETFs, stocks, bonds, crypto)
Second homes and rental property
Loans you've made to others
The core idea is straightforward: if you have wealth generating income, you pay tax on that income.
The problem — and the source of years of legal battles — was how that income was calculated.
The Old System: Paying Tax on Returns You Never Made
Until recently, Box 3 used a simple but deeply flawed method: the government assumed a fixed return on your assets, then taxed 36% of that assumed return.
It didn't matter whether your portfolio actually earned that return. Whether markets were up or down, you paid the same amount.
2025 assumed rates (current transitional system):
Bank savings: 1.44%
Investments and other assets: 5.88%
Debts: 2.62%
Tax-free allowance (heffingsvrij vermogen):
2025: €57,684 per person (€115,368 for fiscal partners)
2026: €59,357 per person (€118,714 for fiscal partners)
Tax rate: 36% on the deemed return above the threshold
So for a €200,000 investment portfolio in 2025:
Taxable assets: €200,000 − €57,684 = €142,316
Deemed return: €142,316 × 5.88% = €8,368
Box 3 tax: €8,368 × 36% = €3,012
Whether your portfolio returned 8% or -5%, the bill was the same.
In years of low interest rates — like 2016–2020 — many savers earned almost nothing on their deposits but still owed tax on a 4–5% assumed return. That's what triggered the legal challenge.
The 2021 Christmas Ruling: The Supreme Court Steps In
On 24 December 2021 — hence "Christmas ruling" (Kerstarrest) — the Dutch Supreme Court ruled that the fixed-return Box 3 system violated the European Convention on Human Rights. Specifically, it discriminated against savers who kept their money in low-yield bank accounts and were taxed as if they'd invested it all.
This forced the government to act. And it set off a chain of events that's still playing out.
The Transitional System (2023–2027): Better, But Not Fixed
The government's immediate response was to introduce a transitional system that at least differentiates between types of assets — assigning savings and investments different assumed returns rather than blending them.
That's the system running now and through 2027.
It's an improvement. Savers with mostly cash in bank accounts pay meaningfully less than investors with equities. But the Supreme Court has made clear this still doesn't pass the test — it's still based on assumed returns, not actual ones.
What this means in practice right now:
Since July 2025, taxpayers can challenge their Box 3 assessment by filing an Opgaaf Werkelijk Rendement (OWR) form — a declaration of actual return. If your real investment return was lower than the assumed rate, the Belastingdienst will use the lower number.
This is significant. If 2022 was a bad year for your portfolio (and it was), you may be able to claim back overpaid Box 3 tax for that year. The OWR form covers years back to 2017 in some cases, provided the relevant assessments weren't already finalised before December 2021.
Worth checking if you've had losing years.
The 2028 System: What Actually Changes
On 19 May 2025, the government submitted the Wet werkelijk rendement box 3 (Act on the Actual Return on Box 3) to parliament. On 12 February 2026, the Tweede Kamer passed it with 93 out of 150 votes. It now goes to the Senate. If approved, it takes effect 1 January 2028.
This is the real overhaul.
The core principle: Tax your actual return, not an assumed one.
How it works for different asset types:
Savings accounts: Tax on actual interest earned. Simple and fair — if you earned €800 in interest, that's your taxable amount.
Investments (stocks, ETFs, bonds, crypto): This is where it gets more complex. The new system uses a capital growth tax (vermogensaanwasbelasting): you pay tax annually on both income received (dividends) and changes in value — including unrealised gains.
That last part is controversial and we'll come back to it.
Real estate (second homes, rental property): A capital gains tax applies — meaning rental income is taxed each year, but increases in property value are only taxed when you sell. This is the more intuitive version of the tax and is less contentious.
Startup shares: Also capital gains tax — only taxed on realisation.
What replaces the tax-free threshold: Instead of a €57,684 tax-free capital allowance, the new system introduces a €1,800 tax-free return per year. This is a fundamental structural change — you're no longer exempt based on how much you have, but based on how much you earn.
Loss compensation: Losses above €500 in any year can be carried forward indefinitely to offset future gains. This is a meaningful protection that doesn't exist in the current system.
Tax rate: Still 36%.
The Big Controversy: Taxing Unrealised Gains
Here's the part that's generating the most debate.
Under the 2028 system, if your €50,000 ETF portfolio increases in value by €4,000 in a given year — even if you haven't sold anything — you owe 36% × €4,000 = €1,440 in Box 3 tax.
Most European countries with capital gains taxes only charge when you actually sell. The Netherlands would be unusual in taxing paper profits annually.
Critics — including a parliamentary majority — have already signalled they don't like this. Immediately after passing the bill, parliament voted for a motion asking the government to come up with a plan to move to realised gains onlybefore Budget Day 2028. So the 2028 system, even as it's being approved, is already being flagged for revision.
The Minister of Finance has also indicated he'll be proposing amendments before the Senate vote, concerned that the Senate might reject the bill entirely in its current form.
In other words: the saga continues. The direction of travel is clear (tax actual returns), but the exact destination is still moving.
Timeline Summary
Year | What's happening |
2021 | Supreme Court Christmas ruling — current system declared unlawful |
2023–2024 | Transitional system introduced — still deemed returns, but per asset type |
July 2025 | OWR form launched — claim back overpaid tax if actual return was lower |
May 2025 | New Box 3 bill submitted to parliament |
February 2026 | Tweede Kamer passes the bill (93/150 votes) |
2026–2027 | Senate review; potential amendments |
January 2028 | New system planned to take effect (subject to Senate approval and possible further changes) |
2028+ | Parliament wants another revision toward realised-gains-only model |
What Should You Do Right Now?
1. Check if you're owed money back (OWR form) If your actual returns in any year from 2017 onwards were lower than the deemed return, you may have overpaid. The OWR form is available on belastingdienst.nl. Particularly worth checking for 2022, when equity markets dropped significantly.
2. Don't restructure your investments around 2028 rules yet The final shape of the 2028 system is still in flux. Parliament has already signalled changes are coming. Making major portfolio moves now based on a system that's still being amended would be premature.
3. Keep records of your cost basis Under the new system, you'll need to know what you paid for assets to calculate gains and losses. Start keeping annual records now if you're not already.
4. Stay updated This is an area where the rules genuinely will change before 2028. A single source of truth for the final confirmed rules will be belastingdienst.nl.
Frequently Asked Questions
When does the new Box 3 system start? The new Wet werkelijk rendement box 3 is planned to take effect on 1 January 2028, provided it passes the Senate. Given ongoing debate, the exact implementation date may shift.
Will Box 3 tax get lower or higher under the new system? It depends on your actual returns. In good years, investors with high returns could pay more than under the current deemed system. In bad years, they'd pay little or nothing — and could carry losses forward. For conservative savers, the new system is likely to be fairer.
What is the OWR form and should I file one? The Opgaaf Werkelijk Rendement (OWR) form lets you declare your actual Box 3 return. The Belastingdienst then uses the lower of your actual return or the deemed return. If your portfolio had a bad year, it's worth filing. The form has been available since July 2025.
Does the new system tax unrealised investment gains? Yes — the current approved bill taxes annual increases in portfolio value even if you haven't sold anything. This is highly controversial and parliament has already asked the government to revisit this before 2028.
What happens to the €57,684 tax-free allowance? Under the 2028 system, it's replaced by a €1,800 annual tax-free return — meaning small investors with modest actual returns may pay no Box 3 tax at all, while larger investors with significant returns may pay more.
This article is based on 2025–2026 legislative information from Belastingdienst.nl, the Tweede Kamer, and official government sources. Tax rules are changing — confirm current rules before making any decisions.
→ Wondering how Box 3 changes affect your Dutch FIRE number? Model your specific situation with the calculator
