Unrealized Capital Gains Tax in the Netherlands: The Complete 2026 Box 3 Guide

In February 2026, the Dutch House of Representatives passed a landmark law that could change how millions of residents in the Netherlands pay tax on their savings and investments. The Wet werkelijk rendement box 3 or the Actual Return in Box 3 Act introduces a 36% tax on unrealized capital gains from 1 January 2028, pending final Senate approval.

For investors, expats, and anyone with savings or a second property in the Netherlands, this is one of the most important tax changes in decades. In this guide, we explain what unrealized capital gains tax means, how the new Dutch system works, who is affected, and what steps you can take to prepare.

Important Update (February 2026)After passing the lower house, Dutch Finance Minister Eelco Heinen announced on 25 February 2026 that the bill will be amended before going to the Senate, due to growing political and public criticism. The unrealized gains component may be reduced or replaced with a realized-gains-only system. This guide covers the bill as currently written; expect further updates before 2028.

What Are Unrealized Capital Gains?

A capital gain is the increase in value of an asset such as a share, bond, or property since you bought it. A gain is realized when you sell the asset and receive the money. A gain is unrealized when the asset has increased in value on paper, but you have not yet sold it.

For example, if you bought shares worth €10,000 and they are now worth €15,000 but you have not sold them, you have an unrealized gain of €5,000. Under the new Dutch system, you could owe tax on that €5,000 even without selling a single share.

Most countries around the world only tax capital gains when they are realized. The Netherlands is proposing to tax them annually, even on paper. A survey by the Dutch Association of Tax Advisors found that none of the 12 surveyed European countries currently uses a capital growth tax of this kind.

Understanding the Dutch Box System

The Netherlands divides personal income into three categories, called boxes, each taxed differently:

• Box 1: Income from work and home ownership (salary, freelance income, pension). Taxed at progressive rates up to 49.50% in 2026.
• Box 2: Income from a substantial interest (owning 5% or more of a company). Taxed at 24.5%–33%.
• Box 3: Savings and investments (bank accounts, shares, bonds, crypto, second properties). This is the box being reformed.

Box 3 has been controversial for years. The previous system taxed a fictitious assumed return rather than actual earnings, which the Dutch Supreme Court ruled unconstitutional in December 2021, triggering the current reform process.

The New Box 3 System: What Changes from 2028?

The new system introduces a dual-track approach to taxing investment returns:

Track 1: Capital Growth Tax (Main Rule)

This applies to most Box 3 assets including shares, bonds, cryptocurrencies, and savings accounts. Under this track:

• You pay 36% tax annually on both income received (dividends, interest, rent) AND unrealized increases in asset value
• If your assets fall in value, that unrealized loss is deductible
• The old €57,684 per-person asset threshold is replaced by a €1,800 annual tax-free return
• Losses can be carried forward indefinitely, provided they exceed €500

Track 2: Capital Gains Tax (Exception)

This more traditional approach applies to real estate and shares in qualifying startups only:

• Tax is only due when you sell (or gift, emigrate, or die)
• Annual paper gains are not taxed while you hold the asset
• The rate is still 36%, but only applied at the point of realization

The key difference: under Track 1, you could owe tax even if your investments have not generated any cash. Under Track 2, you only pay when you actually sell.

Current vs. New Box 3 System: Side-by-Side Comparison

Feature	Current System (until 2027)	New System (from 2028)
Basis of tax	Assumed/fictitious return	Actual return
Unrealized gains taxed?	No	Yes (stocks, bonds, crypto)
Tax rate	36% on assumed return	36% on actual return
Real estate	Assumed return	Capital gains on realization
Startup shares	Assumed return	Capital gains on realization
Tax-free threshold	€57,684 per person (assets)	€1,800 annual return
Loss carry-forward	Not applicable	Yes, if losses exceed €500
Supreme Court status	Ruled unconstitutional	New reform (pending Senate)

Who Is Affected?

The new rules will affect a wide range of people in the Netherlands:

• Private investors: Anyone with stocks, bonds, ETFs, or crypto in a personal account (not a pension fund) will be taxed on annual gains, whether or not they sell.
• Expats with savings: Expats who qualify as Dutch tax residents and hold assets in Box 3 will be subject to the new rules.
• Second-home owners: Those with a holiday home or investment property in Box 3 will pay capital gains tax on sale, not annually on paper gains.
• Angel investors: Investors in qualifying startups (Track 2) are largely protected from unrealized gains tax.
• Company owners (5%+ stake): These fall under Box 2 not Box 3 and are not directly affected by this reform.

Approximately 400,000 additional Dutch taxpayers are expected to need to file a Box 3 return under the new €1,800 threshold, compared to the old €57,684 asset threshold.

Calculate Your Dutch Net IncomeWondering how the Box 3 changes will affect your take-home pay? Use our free Dutch Tax Calculator for an instant 2026 estimate.→ Try the Dutch Tax Calculator at dutchtaxcalculators.com

Why Is the Netherlands Doing This?

The reform did not come from a political desire to tax paper gains. It was driven by a constitutional crisis

In December 2021, the Dutch Supreme Court ruled that the old Box 3 system which taxed a flat assumed return regardless of actual earnings violated the European Convention on Human Rights. Taxpayers who earned less than the assumed rate were effectively paying tax on income they never received.

Since the ruling, the Belastingdienst has been required to provide legal redress to affected taxpayers, costing the Dutch treasury an estimated €2.3–2.4 billion per year in lost revenue. The new actual-return system is the government’s solution to replace an unconstitutional regime with a legally sound one.

However, the political response has been fierce. Prince Constantijn of the Netherlands called the proposal a signal that the country is “not open for business.” The international press covered it widely. On 25 February 2026, Finance Minister Eelco Heinen announced that amendments to reduce or remove the unrealized gains component are being planned.

What Should You Do Now? Practical Steps

1. Do not panic yet. The bill has not been fully approved. The Senate must still debate it, and the Finance Minister has signalled that the unrealized gains element may be significantly amended before it becomes law.
2. Know your Box 3 assets. Make a list of everything you hold in Box 3: shares, bonds, crypto, savings accounts, second properties. Understand which track each asset would fall under.
3. Check if your property or startup shares qualify for Track 2. Real estate and qualifying startup investments will only be taxed on realization, not annually. Confirm whether your assets meet the criteria.
4. Consider your emigration position. If you plan to leave the Netherlands, note that the bill includes an exit tax provision for Box 3 assets (excluding Dutch property). Get advice before moving.
5. Speak to a Dutch tax adviser. This is a complex and evolving area. A qualified belastingadviseur can assess the specific impact on your portfolio and advise on legal optimization strategies.
6. Use our Dutch Tax Calculator. Understand your overall Dutch income tax position today, including Box 1 salary tax and the 30% ruling if applicable, while the Box 3 rules are finalized.

Frequently Asked Questions

Does the Netherlands currently tax unrealized capital gains?

Not yet. The current Box 3 system (until end of 2027) taxes a fictitious assumed return, not actual or unrealized gains. The new system taxing unrealized gains is planned for 1 January 2028, subject to Senate approval and possible amendments.

What is the tax rate on capital gains in the Netherlands under the new system?

The flat rate under the new Box 3 system is 36%, applied to actual returns including unrealized gains for most assets. This is the same rate applied under the current transitional regime.

Are cryptocurrencies affected by the Dutch unrealized gains tax?

Yes, under the current bill, cryptocurrencies fall under Track 1 (capital growth tax). This means annual increases in crypto value would be taxed at 36%, even if you have not sold. However, amendments to the bill are expected, so this position may change.

Is real estate in the Netherlands subject to unrealized gains tax?

No. Real estate in Box 3 (such as a second home or buy-to-let property) falls under Track 2 (capital gains tax), meaning you only pay tax when you sell, give away, or emigrate. Rental income is taxed annually.

What is the tax-free allowance for Box 3 under the new system?

The new system replaces the €57,684 per-person asset threshold with a €1,800 annual tax-free return. This means many more people with modest savings or investments will need to file a Box 3 return for the first time.

What happens if I leave the Netherlands before 2028?

The bill includes an exit tax provision for Box 3 assets located outside the Netherlands. If you emigrate, a deemed disposal is triggered for tax purposes. Dutch-based real estate is excluded from this exit charge since the Netherlands retains taxing rights over it under international treaties. Seek advice before emigrating if you hold significant Box 3 assets.

Final Thoughts

The Netherlands’ proposed unrealized capital gains tax is one of the most discussed and debated tax changes in Europe in 2026. It is driven not by ideology, but by a legal necessity to replace an unconstitutional system with something workable before 2028.

The good news is that the law is not yet final. Amendments are expected, and the long-term goal of the current coalition is a pure realized capital gains tax meaning you would only pay when you actually sell. Stay informed, understand your current Box 3 position, and take advice before making significant investment or emigration decisions based on the current text of the bill.

And if you want to understand your overall Dutch tax position today including salary tax, the 30% ruling, and more our free Dutch Tax Calculator gives you an instant, accurate estimate.