Netherlands Box 3: Unrealised Gains Tax — What to Do Before 2028

The Box 3 Story: From Deemed Returns to Unrealised Gains

To understand what is coming in 2028, you need to understand where Box 3 has been — and why the trajectory matters.

The Netherlands taxes personal income under a three-box system:

• Box 1: Employment income, business profits, and imputed rental value of the primary residence — taxed at progressive rates up to 49.5%
• Box 2: Income from substantial shareholdings (5%+) in companies, including dividends and capital gains — taxed at 33% (from 2024)
• Box 3: Savings and investments — everything else, from bank accounts to investment portfolios to rental properties to foreign financial assets

Box 3 was never a straightforward wealth tax. It was, for decades, a deemed return tax: the Dutch government assumed that you earned a fixed notional return on your Box 3 assets and taxed that deemed return, regardless of what you actually earned.

The Original Deemed Return System (Pre-2021)

Under the original regime, a single notional return of 4% was applied to all Box 3 assets above the exempt threshold, regardless of the asset's actual performance. That 4% notional return was then taxed at 30% (later 31%, then 31%+), producing an effective wealth tax of approximately 1.2% of asset value per year.

During the low-interest era of 2010–2021, this created a significant injustice. Savers holding cash in bank accounts earning 0.1% were being taxed as if they had earned 4%. The notional return bore no relationship to actual returns, particularly for risk-averse savers.

The Supreme Court Ruling: December 2021

On 24 December 2021, the Dutch Supreme Court (Hoge Raad) issued a landmark ruling: the existing Box 3 regime violated the property rights protection of Article 1 of Protocol 1 of the European Convention on Human Rights, and the non-discrimination principle of Article 14 ECHR, because the deemed return system taxed individuals on income they demonstrably had not received.

The ruling created an immediate crisis for the Dutch tax authority (Belastingdienst) and the Ministry of Finance. Billions in potential refund claims were filed. The government was required to provide redress to taxpayers who had been overtaxed — a process that has involved complex transitional legislation and significant fiscal uncertainty.

The Bridging Legislation (2023–2027)

In response to the Supreme Court ruling, the Dutch government introduced transitional Box 3 legislation for the years 2023–2027. Under this bridging regime, Box 3 assets are divided into three categories with different deemed return percentages intended to more accurately reflect actual market returns:

Asset Category	Deemed Return 2024
Bank savings and deposits	~1.03%
Other assets (investments, real estate, etc.)	~6.04%
Debts (mortgages on rental property, etc.)	~2.47%

The "other assets" category carries a deemed return of approximately 6% — applied to investment portfolios, rental properties, private equity interests, and similar holdings. At the 36% Box 3 tax rate (for 2024), this produces an effective tax rate of approximately 2.17% of asset value per year.

For a Dutch resident with €5 million in investment assets classified as "other assets," the annual Box 3 tax bill under the current bridging regime is approximately €108,500 — irrespective of actual investment performance in that year.

The bridging legislation is itself subject to ongoing litigation. Multiple Dutch courts have ruled that the bridging regime also violates the ECHR in specific circumstances, and the full resolution of those cases is still pending.

The 2028 Target: Actual Return Taxation

The Dutch government has confirmed that the long-term Box 3 reform, effective from 2028, will move to taxation of the actual return on Box 3 assets. The proposed structure:

• Income returns (dividends, interest, rental income) taxed at 36% in the year they arise
• Capital returns (unrealised appreciation in asset value) taxed at 36% in the year they accrue — whether or not the asset has been sold

The second element — annual taxation of unrealised capital gains — is what distinguishes the 2028 system from any existing European wealth or investment tax framework. Under the proposed system, if your investment portfolio increases in value by €500,000 in 2028, you owe €180,000 in Box 3 tax on that unrealised appreciation, even if you have not sold a single share.

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The Practical Impact: Why This Matters

The Cash Flow Problem

Unrealised gains taxation creates a cash flow problem that does not exist under realised gains taxation. When you sell an asset, you have the proceeds to pay the tax. When you are taxed on an unrealised gain, you owe tax on an increase in paper value — but the cash to pay that tax must come from somewhere else.

For investors in:

• Illiquid private equity or venture capital — there is no market price and no liquidity to fund the tax bill
• Investment property — the property may have appreciated significantly, but rental income may be insufficient to fund the annual unrealised gains tax
• Concentrated positions in single companies — selling shares to fund the tax bill may not be desirable or possible

The cash flow problem is not theoretical. In the US, proposals for a mark-to-market wealth tax on unrealised gains have repeatedly foundered partly on this exact issue. The Netherlands is proposing to implement it.

The Compounding Drag

At a 36% tax rate on unrealised appreciation, Box 3 becomes a significant drag on long-term wealth compounding. Consider:

• An investment portfolio growing at 7% per year
• Box 3 tax on unrealised appreciation: 36% × 7% = 2.52% per year taken from the portfolio
• Net real growth rate after Box 3: approximately 4.5%

Over 20 years, the difference between 7% annual compounding and 4.5% annual compounding on a €5 million portfolio is enormous — more than €20 million in forgone wealth accumulation.

Affected Asset Classes

Box 3 captures most assets held by Dutch tax residents outside of their primary residence (which falls in Box 1) and business interests (which may fall in Box 2 via substantial shareholding). Specifically:

• Publicly listed equities and ETFs — the core holding of most investment portfolios
• Bonds and fixed income — including government bonds, corporate bonds, structured products
• Investment property — second homes, rental properties in the Netherlands and abroad
• Private equity and fund interests — including stakes in unlisted companies below the 5% Box 2 threshold
• Cash and savings above the exempt threshold — the per-person exempt threshold is €57,000 in 2024
• Foreign financial accounts and foreign real estate — Dutch residents pay Box 3 on worldwide assets
• Cryptocurrency — classified as an "other asset" for Box 3 purposes

The personal exempt threshold (€57,000 per person, €114,000 for fiscal partners) means that the Box 3 problem is concentrated among genuinely wealthy individuals — but for those with substantial passive wealth, the impact of the 2028 reform is material.

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Planning Options: What Dutch-Resident Investors Can Do

Option 1: Relocation — The Most Comprehensive Solution

Ceasing Dutch tax residency before 2028 is the most complete solution. If you are no longer a Dutch tax resident when the new Box 3 regime takes effect, it does not apply to your global assets going forward.

The Netherlands determines tax residency based on facts and circumstances — the totality of your connection to the Netherlands, including where you live, where your family is, where your economic interests are centred, and where you spend your time. There is no explicit day-count rule equivalent to the UK's Statutory Residence Test.

The Dutch tax authority (Belastingdienst) scrutinises departures carefully, particularly where significant wealth is involved. Merely registering a departure (Emigratie) at the municipality and obtaining a foreign address is not sufficient to establish non-residency in cases where substantive connections to the Netherlands remain.

Genuine relocation requires:

• A real home in the new jurisdiction — not a hotel address or a shared residence
• Genuine physical presence in the new jurisdiction for the required period
• Severing or significantly reducing Dutch connections — including Dutch property, Dutch business interests, and Dutch social connections
• Obtaining a Tax Residency Certificate from the new jurisdiction's tax authority

Popular destination jurisdictions for Dutch residents planning tax residency planning exits include:

Jurisdiction	Personal Tax	Property Tax	Notes
UAE	0%	0%	No income, gains, or wealth tax on individuals
Portugal (IFICI)	20% flat	Standard	10-year qualifying period
Malta	15% flat (non-dom)	Standard	Minimum annual tax of €15,000
Switzerland	Lump sum option	Cantonal variations	Lump sum negotiated with canton
Cayman Islands	0%	0%	No taxation of individuals
Singapore	22% (top rate)	Stamp duty on property	Territorial system; foreign income often exempt

The Dutch Exit Tax Under Box 2

A critical planning consideration for Dutch residents with substantial shareholdings (5%+ in a company — Box 2 assets) is the exit tax that applies on departure. Under Article 4.16 of the Dutch Income Tax Act, ceasing Dutch residency triggers a deemed disposal of Box 2 shareholdings at market value — meaning any unrealised capital gains on those shareholdings are crystallised and taxed on departure.

The current Box 2 tax rate is 33% (from 2024). For an entrepreneur with a significant stake in a valuable company, the exit tax can be a substantial barrier to departure. However:

• Payment deferral is available — the exit tax liability can be deferred and paid in instalments over 10 years
• Tax treaties between the Netherlands and many destinations limit or modify the exit tax
• Planning the timing of a Box 2 exit tax event relative to a business sale can sometimes reduce the total tax burden compared to remaining Dutch-resident

Box 3 assets do not trigger an exit tax on departure — only Box 2 shareholdings do. This means that for investors whose wealth is primarily in Box 3 assets (investment portfolios, property) rather than Box 2 company stakes, the barriers to departure are lower.

Option 2: Box 2 Restructuring

Shifting assets from Box 3 to Box 2 by interposing a Dutch holding company (BV) is possible but must be done carefully. If you transfer your investment portfolio into a Dutch BV in which you hold 5%+, the portfolio moves from Box 3 (where the new actual return tax will apply) to Box 2 (where tax is only due on actual distributions or disposal of the shares).

The restructuring achieves deferral — the investment returns accumulate within the BV at the 25.8% corporation tax rate (for profits above €200,000), with Box 2 tax (33%) due only when dividends are paid or the shares sold. The combined rate on distributed earnings is approximately 40%+, which is worse than the 36% Box 3 rate on actual returns — but the deferral benefit (particularly for long compounding periods) can make this advantageous.

Anti-abuse provisions are a significant consideration. The Dutch Belastingdienst has signalled that it views Box 3 to Box 2 conversions undertaken primarily for tax avoidance purposes sceptically, and the legislature is expected to introduce anti-abuse rules limiting this strategy during the transitional period. The window for this restructuring is narrowing.

Option 3: Asset Reallocation Within Box 3

Certain assets are exempt from Box 3 or taxed under different rules:

• Main residence — falls in Box 1 via the eigenwoningforfait (imputed rental value) rather than Box 3
• Business assets in an active business — held in Box 1 (sole traders) or Box 2 (company shares with 5%+ holding)
• Qualifying pension products — accrual under annuity products and employer pension schemes is outside Box 3
• Green investments (groene beleggingen) — Dutch green investment funds receive a partial exemption

Reallocating wealth from taxable Box 3 assets into pension vehicles, primary residence equity (through mortgage repayment), or qualifying business investments reduces the Box 3 taxable base. This is incremental planning rather than a structural solution to the 2028 problem — it reduces exposure but does not eliminate it for those with substantial passive wealth.

Option 4: Engaging the Treaty Position

The Netherlands has tax treaties with over 100 countries. For Dutch residents who establish genuine residence in a treaty country, the treaty tiebreaker may allocate taxing rights on investment income and gains to the new country of residence rather than the Netherlands.

The treaty position does not eliminate Dutch Box 3 tax on Dutch-source assets (such as Dutch real estate) — residence state and source state taxing rights interact differently for different asset classes. But for foreign financial assets — foreign equities, foreign bank accounts, foreign property — treaty relief can significantly reduce or eliminate Dutch Box 3 exposure even for individuals who retain some Dutch connections.

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The Timeline: Why Acting in 2025–2026 Is Critical

The window for effective Box 3 planning is genuinely constrained by the 2028 implementation date — but the constraint is not simply one of time.

Relocation takes 12–24 months to execute properly. Establishing genuine tax residency abroad requires more than filing a departure notice. Finding and securing appropriate accommodation, managing the transition of business and banking arrangements, severing Dutch ties methodically, obtaining the required documentation, and achieving a position robust enough to withstand Belastingdienst scrutiny takes time.

The Belastingdienst scrutinises departures. Wealthy individuals who announce their departure in 2027 — one year before the 2028 Box 3 reform — will receive significantly more scrutiny than those who departed in 2025 or 2026 as part of a genuinely motivated life decision. The optics matter, and the quality of the departure documentation matters even more.

Restructuring options are being closed. The Dutch Ministry of Finance has signalled its intention to limit Box 3 avoidance strategies during the 2023–2028 transitional period. Anti-abuse provisions targeting Box 3-to-Box 2 conversions are expected. The available restructuring options today are more extensive than those that will be available in 2027.

Pension and property decisions have long lead times. Redirecting future wealth accumulation into pension vehicles and reducing Box 3 exposure through legitimate reallocation requires years of consistent action, not a last-minute portfolio reshuffle.

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Comparing the Tax Burden: Netherlands Box 3 vs. Alternatives

Scenario	Annual Tax on €5M Portfolio at 7% Return
Netherlands Box 3 (current bridging, investment assets)	~€108,500 (2.17% of AUM)
Netherlands Box 3 (proposed 2028, actual return)	~€126,000 (36% of €350K gain)
UAE resident, same portfolio	€0 (no personal capital gains or wealth tax)
Portugal IFICI resident, foreign portfolio	Likely €0 (foreign gains typically exempt under IFICI)
UK resident (offshore bond wrapper)	Deferred; ~£70,000 on 5% notional withdrawal
Switzerland (lump sum regime)	Lump sum negotiated; often far below marginal rates

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Key Takeaways

• The Dutch Supreme Court's December 2021 ruling invalidated the original Box 3 deemed return system; the bridging legislation (2023–2027) applies differentiated deemed returns of up to ~6% on investment assets
• The 2028 Box 3 reform will tax actual returns — including unrealised capital gains — at 36%, creating an annual cash flow obligation irrespective of whether assets have been sold
• Relocation before 2028 is the most comprehensive solution, but requires 12–24 months and genuine severance of Dutch connections
• Box 2 restructuring achieves deferral but anti-abuse provisions are being tightened and the Box 2 exit tax on departure must be factored into the analysis
• The Box 2 exit tax (33% on unrealised gains in substantial shareholdings) applies on departure — payment deferral is available, but the liability must be planned around
• Acting in 2025 or 2026 produces materially better outcomes than waiting until 2027 — both in terms of available planning options and Belastingdienst scrutiny risk

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How HPT Group Approaches Dutch Box 3 Planning

HPT Group advises Dutch-resident entrepreneurs, investors, and family office clients on the full range of Box 3 exit strategies — from residency transitions to Box 2 restructuring to treaty-based planning for those retaining Dutch assets. Our analysis incorporates the Box 2 exit tax, the Dutch residency facts-and-circumstances test, and the specific requirements of destination jurisdictions.

We do not advise on paper departures. We advise on genuine, well-documented transitions that achieve the intended tax outcome and withstand scrutiny from the Belastingdienst. The clients who engage us in 2025 are the ones with the most planning flexibility. The window is open now — and it is closing. Speak to an advisor about your Box 3 exit options.