1. What Prinsjesdag Actually Is

Prinsjesdag is not a bank holiday and not a carnival. Article 65 of the Constitution says that on the third Tuesday of September the King, or someone on his behalf, sets out government policy to a joint session of the States General. That speech is the Troonrede. The same day the cabinet files the national budget and the Miljoenennota, the thick explanation of where the money comes from and where it goes.
The gold coach, the hats and the balcony photos are ceremony. The binding text for your payroll and your huur is in the Tax Plan, the departmental budgets and the tables at the back of the Miljoenennota. Those papers take effect on different dates. Some measures bite on 1 January 2027. Some are already law. Some need the Eerste Kamer and will slip.
If you do not vote in the Tweede Kamer you still live inside these numbers: Box 1 on your salary, Box 3 on savings and a second home, the zorgpremie letter in November, the NS tariff, the petrol board on the A2.

2. Calendar: 15–17 September

Den Haag traffic and tram 1 will be ugly on the 15th. If you work near the Binnenhof, go remote.

3. Why This Budget Is Fragile

Jetten I is a minority cabinet. D66, VVD and CDA do not hold a Tweede Kamer majority on their own. Every sensitive line — wealth tax, social security, development aid, fuel duty — needs votes from outside the three. Jetten has said the package contains “forse handreikingen” to the opposition and that the budget was built “for ten parties.” The government still needs sufficient support in parliament for the package to pass.
The coalition negotiated through night sessions to close the 2027 budget at the end of August. Box 3 and social-security cuts were the two files that took longest. D66 and CDA wanted wealth to pay more; VVD was concerned about support on the right, including in the Senate. The compromise reported on 1 September is delay on Box 3, partial rollback of social cuts, extra purchasing-power money, and a slower fade of the fuel-duty discount.
A first budget from a minority cabinet still has to clear parliament. Read the official papers on Tuesday, then follow the first week of debate before treating any leaked figure as settled.

4. What Has Leaked — and What Has Not

Dutch media, citing coalition sources, reported this package before Prinsjesdag. None of it is your assessment until the official documents are published. Treat every row below as leaked / expected — not final until the official Prinsjesdag documents are published, and still subject to parliamentary approval.

If Tuesday’s PDF contradicts the leak, the PDF wins.

5. Box 3: Savings, Shares, Second Homes

Box 3 is tax on savings and investments that are not your main home and not a substantial shareholding (that is Box 2). After the 2021 Christmas judgment the system has been in a running repair. For tax year 2026 you still live under a forfait: the tax office pretends your assets earned a fixed return, then taxes that fiction at 36 percent, unless you prove a lower actual return through the tegenbewijs / Opgaaf Werkelijk Rendement route.
Published 2026 working numbers (verify on belastingdienst.nl when you file):

A later bill would have taxed actual returns from 1 January 2028, including unrealised gains on liquid assets — tax on paper profits. The Tweede Kamer passed that bill in February 2026. The proposed Box 3 reform is facing delays in the Senate. Leaks say the coalition may not force a Senate vote and may design a system closer to tax-on-sale (vermogenswinst) instead of tax-every-year-on-the-rise (vermogensaanwas). If that hold is confirmed on 15 September, the original 2028 design slips. The current forfait-plus-counterproof world would then last longer. That is still a political outcome, not a filed assessment.
Expats with the 30% ruling: partial non-resident status, which kept foreign Box 2 and Box 3 assets out of the Dutch net, died for most people on 1 January 2025. A transitional group — ruling applied in the last 2023 payroll — may still elect that status through 31 December 2026. From 1 January 2027 every ruling holder is a full Dutch resident for Box 2 and Box 3, treaties aside. If you have a flat in Lisbon or a brokerage in Singapore, 2026 is the year to model 1 January 2027 with an advisor. That deadline sits in the ruling law already. Prinsjesdag does not create it.

6. The 30% Ruling in 2026 and 2027

The scheme is still 30 percent through the whole of 2026. It does not drop on Prinsjesdag Tuesday. It is scheduled to drop on 1 January 2027 for almost everyone whose facility first applied in 2024 or later. The pre-2024 payroll group keeps 30 percent for the rest of their term. Official guidance notes that the effective date remains subject to the parliamentary process.

The cancelled 30/20/10 taper is dead. Do not use an article from 2024 that still prints it. RVO states that entry into force can still depend on parliament; employers are already budgeting the 27 percent path.
The coalition agreement said the expatregeling stays. A change to that line on 15 September would be news. Plan on 27 percent in January unless Tuesday’s Tax Plan says otherwise.

7. Income Tax and Higher Earners

Leaks say higher incomes will pay more to fund purchasing-power repairs and delayed social cuts. That can mean a Box 1 rate, a bracket boundary, a levy rebate, or a combination. Without the official table, do not guess your net December salary.
What you can do now: export 2025 and 2026 year-to-date payslips, note whether the 30% ruling is on the strook, and sit on the numbers until the Belastingplan PDF lists the 2027 Box 1 rates. Payroll software will lag by a cycle. January’s first slip is the real test, not a Tuesday tweet.

8. Healthcare, Eigen Risico, Zorgtoeslag

Every resident must hold basic zorgverzekering. Premium letters land in November. The compulsory excess (eigen risico) is the first slice of non-GP care you pay yourself.
Draft law still contains an increase. Coalition leaks said a €60 rise would slip to 2028. That is not the same as a decision that 2027 will not go up. If the delay is in Tuesday’s documents and then survives parliament, the 2027 excess stays nearer today’s level. If the leak does not appear in the official papers, the increase in the existing proposal can still move. Read the official Belastingplan and the zorgverzekeraars’ November letters — not this paragraph — before you budget the excess.
Zorgtoeslag (healthcare allowance) still depends on income and assets. A longer-term plan would align asset tests with the Box 3 tax-free threshold from 2028. That is not this Tuesday’s premium. Check toeslagen.nl after the budget if you are close to the cut-off.

9. Rent, Housing and Buying

Social and mid-rent increases follow separate statutory formulas. Last year’s national story was that rents rose again, with corporation social rent up, but slower than the two years before. Prinsjesdag 2026 will provide the framework for 2027 housing policy: points system, WOZ cap inside the housing-points score, and any freeze or extra index for liberalised contracts. Detailed rent rules still run through housing law and the Huurcommissie after the budget papers appear.
Buyers watch transfer tax. The coalition agreement already pointed to cutting the investor rate from 8 to 7 percent in 2027. Confirm whether that line is in Tuesday’s Tax Plan. Mortgage-interest deduction was left standing in the same agreement.
If your huurcontract renews on 1 July 2027, the relevant index is the one published after Prinsjesdag, not a rumour in a WhatsApp huisgroep.

10. Fuel, NS and Daily Costs

Pump advice prices printed above €2.71 a litre this week as oil firmed. That is the oil market plus current Dutch duty — a 7 September market fact, not a budget law.
Leaks say the temporary duty discount would fade more slowly, with a diesel break extended into 2027 and some cushion into 2028. That is leaked / expected — not final until the official Prinsjesdag documents are published, and still subject to parliamentary approval. It is not a promise the board at the A2 will fall tomorrow.
NS tariffs are a separate ministerial track. Watch any infrastructure line in the Miljoenennota for project names, not for your ov-chipkaart in October.

11. What to Watch in the Documents

When the PDFs drop, search these strings before you read the speeches:

12. Expat Checklist