Box 3 tax is based on what you own and owe on one day, the reference date of 1 January. A legitimate change you make before 1 January 2027 therefore counts for the whole of 2027. At 2026 rates, every €1,000 of savings above the €59,357 allowance costs about €4.61 in tax a year, and every €1,000 of investments about €21.60.
The date is getting extra attention because the cabinet wants to cut the 2027 allowance to €30,846 per person, a proposal that is not yet law (status 14 October 2026). This article shows which year-end moves are allowed, what each one saves in euros and which moves the anti-abuse rules reverse.
Why is 1 January the box 3 reference date?
The Belastingdienst taxes box 3 on the value of your assets and debts at the start of the calendar year, so your 2027 tax follows from your position on 1 January 2027. For 2026 the Belastingdienst uses a deemed return of 1.28% on bank balances (still provisional), 6.00% on investments and 2.70% on debts, and it taxes the result at 36%. Debts only count above a threshold of €3,800 per person.
The rules for 1 January 2027 are not settled yet. The Belastingplan 2027 bill puts the allowance at €60,098, according to the fiscal key table 2027. In a letter of 29 September 2026, the cabinet proposed €30,846 instead, with a deemed return on other assets 1.5 percentage points higher. Parliament would have to pass this before 31 December. A single person with €60,000 in savings would then pay about €134 for 2027 instead of about €3 for 2026, if the savings rate stays at 1.28%. Our article on the box 3 proposals of September 2026 covers the plans.
What can you legitimately do before 1 January 2027?
The moves that work change what you own for good, because you repay, give or spend the money instead of parking it for a few weeks. The table compares the main options for a single person with savings above the allowance, using 2026 parameters because the 2027 percentages have not been set.
| Move before 1 January | Example | Box 3 saving per year (2026 parameters) | Catch |
|---|---|---|---|
| Extra mortgage repayment | €20,000 from savings | about €92 | Money is tied up in your home and you lose some interest relief |
| Repay a car loan | €10,000 loan, €100,000 savings | about €6 | A debt above €3,800 already lowered your box 3 base |
| Gift to your child | €6,908 from savings | about €32 | The money is gone for good |
| Buy green investments | €26,715 in 2026, €200 in 2027 | about €150 in 2026, about €3 in 2027 | The exemption almost disappears in 2027 |
| Sell investments, buy back in January | €200,000 | about €3,398 at stake | Reversed by the anti-abuse rule |
Paying extra off your mortgage
An extra repayment moves money out of box 3, because the mortgage on your own home (eigenwoningschuld) is a box 1 debt. Repaying €20,000 from €100,000 in savings cuts your box 3 bill at 2026 rates from about €187 to about €95. That €92 saving stays the same under the proposed 2027 allowance, as long as your savings remain above it. In box 1 you save €800 a year at 4% interest, but you lose up to 37.56% in mortgage interest relief in 2026, which still leaves about €500. According to Rabobank, you can usually repay 10% or 20% of the original loan each year without a penalty. Repaid money is hard to get back, as our article on overpaying your mortgage explains.
Paying off consumer debt
Repaying a car loan from savings saves less box 3 tax than many people expect, because that debt already lowered your box 3 base. With €100,000 in savings and a €10,000 car loan, repaying before 1 January saves only about €6, since the part above the €3,800 threshold was already deducted at 2.70%. Debts below the threshold do not count at all, so repaying a €3,000 loan saves about €14. The real gain lies in the interest you stop paying on the loan.
Giving money away
A gift made before 1 January no longer counts in your box 3 base. In 2026 parents can give a child €6,908 tax-free and anyone else €2,769, according to the Belastingdienst. A child aged 18 to 40 can receive a one-off higher exemption of €33,129, but the separate exemption for a home, the jubelton, ended on 1 January 2024. Giving €6,908 from savings saves you about €32 a year, or about €149 if it comes from investments, so tax is rarely a good reason on its own.
Green investments
Green investments used to be the classic year-end move, but for 1 January 2027 they barely help. In 2026 approved green funds are exempt up to €26,715 per person, with a tax credit of 0.1%, which is worth about €150 if the money comes from savings. Under the Belastingplan 2026, which the Eerste Kamer passed on 16 December 2025, the exemption drops to €200 per person in 2027 and ends in 2028, according to the government's factsheet. Green funds bought in December 2026 therefore save you about €3 for 2027, including the tax credit.
Planned purchases and tax bills
Goods for your own use, such as your car, fall outside box 3, so bringing forward a purchase you had planned anyway saves about €4.61 per €1,000 of savings. Paying a tax bill before 1 January works the same way, because Dutch income tax debts normally do not count as box 3 debts, according to the Belastingdienst. Exceptions include unpaid inheritance tax and a provisional assessment you requested before 1 October that arrived too late to pay.
What doesn't work: shifting investments into savings around 1 January
Selling investments in December and buying them back in January does not lower your box 3 tax. Article 5.24 of the Wet inkomstenbelasting 2001 has ignored such trades since 1 January 2023. The stakes explain the rule, because €200,000 counted as savings instead of investments would save about €3,398 at 2026 rates. It covers money moved from investments to savings in the three months before 1 January and back within three months after it, according to the Belastingdienst. A loan taken out before 1 January and repaid within three months is corrected in the same way.
Unless the trades had business reasons, such as an expected fall in share prices, you report your savings minus the amount moved and your investments plus that amount, as the Belastingdienst explains. Crypto counts as an other asset in box 3, so selling bitcoin before 1 January and buying it back in January falls under the same rule. If your actual return was lower than the deemed return, the counter-evidence scheme is the legitimate route, as our article on box 3 tax on savingsexplains.
Does moving money abroad or into your BV help?
Moving savings to a foreign bank does not help, because box 3 counts your assets in the Netherlands and abroad as long as you live here, according to the Belastingdienst. Parking money in your own BV is caught as well. Assets that move to box 1 or box 2 and come back within three months around 1 January still count in box 3. For up to six months the same applies unless you show business reasons, according to the Belastingdienst page on moving assets out of box 3. Money that stays in the BV for longer falls under corporate tax and box 2, as our article on borrowing from your BV in 2027explains.
How Gylder fits in
Gylder (gylder.nl) is a net worth tracker, not a budgeting app. It records a daily snapshot of your connected accounts, so you can see your balances, investments and crypto on 1 January in one place. Banks connect through PSD2, while DEGIRO is added through a CSV export, so make sure that export covers 1 January. Gylder does not calculate your box 3 tax.
What this doesn't tell you
The examples use 2026 percentages for a single person, because the 2027 percentages have not been set and the 2027 proposal is not yet law (status 14 October 2026). Partners share a joint allowance, and the counter-evidence scheme can lower the bill further. Check the status again after the Raad van State advice at the end of October and after the votes in December, and ask a tax adviser before you move large sums. This article is general information, not financial advice.
Frequently asked questions
What is the box 3 reference date? The box 3 reference date (peildatum) is 1 January of the tax year. Your box 3 tax for the whole year is based on the value of your assets and debts on that day.
Does selling shares before 1 January lower my box 3 tax? Not if you buy them back within three months, because article 5.24 of the Wet inkomstenbelasting 2001 then ignores the trades unless you can show business reasons.
Is the €30,846 allowance for 2027 already law? No. It is a cabinet proposal from 29 September 2026 that both houses of parliament still have to approve before 31 December 2026, while the Belastingplan 2027 bill itself puts the 2027 allowance at €60,098.
Do green investments still lower box 3 tax in 2027? Barely. The exemption falls from €26,715 per person in 2026 to €200 in 2027 and ends completely in 2028.