Netherlands plans realised-gains tax for most Box 3 investments from 2028

The Netherlands plans to move most investments in Box 3 onto a realised-gains tax from 2028. The proposal would cover all financial instruments, including shares, bonds and options, and the government says that amounts to about 90% of Box 3 assets whose value can rise or fall.

The change is important, but it is not law yet. It must be written into a supplementary bill, reviewed and approved by both houses of parliament. International residents and cross-border investors should treat the announcement as a planning signal, not a final tax rule.

What the Dutch government has proposed

In a letter to the House of Representatives dated 29 September 2026, the government chose the fastest route for expanding capital-gains taxation within Box 3. It plans to amend the existing Wet werkelijk rendement box 3, the bill designed to tax actual returns rather than assumed returns.

Under the new proposal:

• all financial instruments, including ordinary shares, bonds and options, would move to a realised-gains system from 2028;
• the government estimates that this would cover roughly 90% of Box 3 assets with value changes;
• the remaining asset categories would move to a full realised-gains system in 2030; and
• property and qualifying interests in start-ups and scale-ups would continue to follow the treatment already proposed in the current bill.

A realised-gains system generally taxes a gain when it is crystallised, such as when an asset is sold. That differs from an accrual-based system, which can tax an annual increase in value even when the investor has not sold the asset.

Why this matters for international residents

For people who live in the Netherlands and hold investments across several countries, the timing of a taxable gain can affect cash flow, record keeping and cross-border reporting. A move away from annual taxation of unrealised gains may reduce the risk of a tax charge before an asset has been sold. It can also make acquisition dates and costs more important.

The proposal may be especially relevant to internationally mobile professionals, entrepreneurs, retirees with investment portfolios and families who hold Dutch and foreign assets. It could also matter to people considering a future move into or out of the Netherlands, because the final law will need rules for migration, losses and assets acquired before the new system starts.

Those rules are not yet available. The government’s letter sets the direction and timetable, but the detailed text of the supplementary bill is still needed.

Other Box 3 changes proposed for 2027 and 2028

The government also proposed measures to help fund the switch. From 2027, the tax-free Box 3 asset threshold would be reduced to €30,846, returning it to its 2020 level. The assumed return applied to “other assets” would rise by 1.5 percentage points in 2027.

From 2028, the new actual-return system would use a tax-free result of €1,000. The government gives the example that, at a 2% savings rate, the first €50,000 of savings would produce no taxable result.

These figures are proposals, not settled entitlements. They may change during parliamentary scrutiny.

What remains uncertain

Several practical questions cannot be answered until the supplementary bill is published. These include:

• which assets will remain outside the realised-gains system in 2028 and 2029;
• how historic purchase prices and pre-2028 gains will be treated;
• how losses can be carried forward or offset;
• what happens when a taxpayer moves into or out of the Netherlands;
• how foreign tax credits and treaty positions will interact with the new rules; and
• what reporting banks and investment platforms will be able to provide.

The government has already warned that banks may not be able to supply data for pre-filled tax returns in the first year. That could place more responsibility on taxpayers to maintain accurate transaction records.

What investors can do now

There is no need to treat the announcement as a reason for an immediate transaction. A more useful step is to make sure records are complete: purchase dates, acquisition costs, corporate actions, dividend statements, sales and foreign tax paid.

People with assets in more than one country may also want to identify where their records are held and whether older cost information can still be recovered. Any decision to sell, transfer or restructure an investment should wait for the detailed legislation and individual professional advice.

What happens next

The government intends to ask the Council of State for urgent advice and wants the supplementary bill to move alongside the 2027 Tax Plan. Its letter says the measure would need to pass the Senate by 31 December 2026 to keep the timetable on track.

The Dutch legislative calendar now lists the supplementary bill for expanding capital-gains taxation, while the government’s Box 3 timeline continues to show 1 January 2028 as the intended start for the new actual-return system.

For now, the key distinction is simple: the policy direction has changed, but the final rules have not yet been enacted.

This article is general information, not tax or legal advice.

Featured image: the Dutch Ministry of Finance at Korte Voorhout 7 in The Hague. Photograph by Tukka, licensed under CC BY-SA 4.0, via Wikimedia Commons. Cropped automatically for display.