The Netherlands Chooses a Tax on Sold Gains for Box 3: What the 2028 Plan Means for Investors

For most of 2026, the Netherlands looked set to tax its investors every year on gains they had not realised. The bill had passed the lower house in February. In mid-September the government admitted it had no majority for a fix and asked the Senate to put the bill on hold.

Two weeks later it made a choice. In a letter of 29 September 2026, signed by Prime Minister R. Jetten, Finance Minister E. Heinen and State Secretary E. Eerenberg and sent to the Senate the next day, the cabinet said it will amend the bill so that from 2028 shares, bonds, options and other financial instruments in box 3 are taxed on their gains only when they are sold. On 13 October, the Senate's finance committee provisionally agreed to that route.

For anyone who holds investments in the Netherlands, or is weighing a move there or away from there, three questions matter: what is taxed now, what the cabinet has chosen, and what is still only a plan.

How Box 3 Works in 2026

The Netherlands has no separate capital gains tax for private investors. Savings and investments fall into "box 3" of the income tax, which in 2026 does not tax what you actually earn. It taxes a deemed return on what you own.

The Belastingdienst's figures for 2026 are:

The rates for bank balances and debts are provisional and will be fixed early in 2027; the 6 percent for investments is final. On investments, a deemed return of 6 percent taxed at 36 percent works out at roughly 2.16 percent of the portfolio's value each year, before the allowance, whether markets rose or fell. For a single person with €500,000 in shares and funds and nothing else, the deemed return is €30,000. After the tax-free wealth is taken into account, box 3 income is about €26,400 and the tax about €9,500.

There is a safety valve. Following rulings of the Supreme Court in June 2024, taxpayers whose actual return is lower than the deemed return must be able to show this and be taxed on the lower figure. The government's letter of 14 September explains why that valve is its problem: taxpayers can pick whichever system is cheaper each year, paying at most on the deemed return in good years and using the counter-evidence route in bad ones. The letter calls the result a heavy annual loss to the budget.

What the Bill Says, and Why It Stalled

The bill, the Wet werkelijk rendement box 3 (parliamentary number 36 748), was adopted by the lower house on 12 February 2026. The government's estimate note sums up its core: from 2028, actual returns are taxed, with a tax on the annual increase in value as the main rule. Interest, dividends and rent are taxed, and so is the change in value of investments over the year, sold or not. Real estate and shares in start-ups are the exception: their value changes are taxed only on sale. The first €1,800 of actual return would be tax-free, losses above €500 could be carried forward without limit, and the rate stays at 36 percent.

The annual tax on paper gains drew the fire. A portfolio that rises from €500,000 to €550,000 with no sale would produce a taxable return of €50,000 and, after the tax-free €1,800, a bill of about €17,350 on money that exists only on a statement. According to the 14 September letter, objections were raised in both chambers, in particular to the value-accrual method and its possible effect on the investment climate.

The Senate debated the bill on 30 June 2026 and, according to its own record, agreed to postpone the vote until announced amendments could be treated with it. On 14 September the government set out four scenarios, from improving the bill to withdrawing it, and asked the Senate to keep waiting.

What the Cabinet Chose on 29 September

The cabinet picked the scenario that the 14 September letter had called the fastest route to taxing gains on realisation. In the words of the 29 September letter, it chooses "the fastest route to bring as much wealth as possible under the capital gains tax" (our translation). The tool is a novelle, an amending bill to the bill already before the Senate.

The core of the plan:

From 2028, financial instruments are taxed on sale. The realisation-based capital gains tax, which the bill already applies to real estate and start-up shares, is extended to all financial instruments, among them shares, bonds and options. According to the letter, that covers about 90 percent of box 3 wealth that changes in value.

From 2030, everything else follows. The remaining assets switch to a full capital gains tax on realisation in 2030.

The cost is covered inside boxes 2 and 3. The letter lists the measures that pay for it.

The financing is where investors will feel the plan first, because several measures start a year before the new system:

The letter gives an example for the €1,000 figure: savers earning 2 percent interest pay no tax on the first €50,000 of their savings. The box 2 cut is meant, the letter says, to encourage business owners to take money out of their companies at a lower rate.

The government is candid about the risks. It calls the timetable ambitious: the novelle must be adopted by the Senate before 31 December, it will ask the Council of State for urgent advice, and it asks the lower house to treat the novelle together with the annual tax plan. It also warns that banks will not be able to supply data for the pre-filled return in at least the first year, which puts a heavy load on taxpayers and on the Belastingdienst.

Where Things Stood on 19 October

The Senate committee discussed the plan with the two finance ministers on 5 October and decided on 13 October. Its short minutes record two decisions. It provisionally agrees with the cabinet's route, on condition that both the urgent advice of the Council of State and the Belastingdienst's implementation test are available when the Senate treats the novelle. And it will wait for the lower house to deal with the novelle before deciding definitively how to handle the bill.

By 19 October, the novelle itself had not been filed in the lower house dossier. That is the honest state of play: a clear political direction, a provisional nod from the Senate committee, and a legal text that still has to be written, advised on, passed by both chambers and implemented within weeks.

Three practical consequences follow.

2026 is unchanged. Nothing in the letters changes the deemed-return system for 2026, including the counter-evidence route.

2027 is where the plan bites first, if it passes. Cutting the tax-free wealth roughly in half and raising the deemed return on other assets would raise the box 3 bill for many savers and property investors in 2027, a year before any realisation-based tax applies.

2028 is a target, not a certainty. The bill still names 1 January 2028, and the cabinet now has a route with provisional Senate backing. But the deadline of 31 December leaves very little room for delay.

Where This Leaves the Netherlands on Europe's Capital Gains Map

Lists of European countries without a capital gains tax sometimes include the Netherlands, because it has no tax by that name. The label misleads. A deemed return of 6 percent taxed at 36 percent is, for a diversified investor, a charge on wealth every year, as the Brief's review of EU countries with no wealth tax sets out.

The cabinet's choice moves the country in a recognisable direction. Taxing gains when they are realised is how most European capital gains taxes work, and it removes the central objection to the bill, the need to pay tax in cash on growth that has not been turned into cash. What it does not do is make the Netherlands a low-tax place for investors: the rate stays at 36 percent in the bill, and the allowances are being cut to pay for the change. The Brief's list of countries with no capital gains tax explains why any such list needs a date on it, and the Dutch case shows how quickly the entry for a single country can change.

What Investors Can Sensibly Do Now

Keep records of your actual return. The counter-evidence route only helps those who can prove what they really earned: year-end statements, dividend records, costs and valuations, kept in an order an inspector can follow. A realisation-based tax will need the same discipline, because purchase prices and dates decide the gain on sale. The Brief's piece on the paper trail that saves you makes the wider case.

Do not restructure for a text nobody has seen. Moving assets into a company, into property or out of the country on the strength of a letter would mean acting on a novelle that has not been published, advised on or voted on. Every restructuring carries its own costs and tax consequences.

Watch the novelle, then the Senate. The decisive dates are the filing of the novelle in the lower house, the Council of State's advice and the Senate vote before 31 December.

If a move is on the table, look at both sides of the border. Leaving the Netherlands raises its own questions, especially for owners of substantial shareholdings, and the Brief's overview of exit taxes covers the mechanics across countries. Staying has a price that changes with each reform, a point the Brief made in the cost of staying. The box 3 saga is a reminder that the tax on savings in the country you already live in can change more in a single autumn than the tax in a country you are only considering.

Work with Sebastian

If you hold significant investments in the Netherlands, or are considering a move to or from the country, and want to understand how the box 3 changes affect your plans, that is the kind of cross-border question Sebastian works on with internationally mobile clients. Book a consultation.