Box 3 in 2026: what's actually changing for savers and investors
The Dutch wealth tax (Box 3) keeps shifting. Here's what changed on January 1, 2026, who is affected, and what to do before the next tax return.
The Dutch wealth tax — Box 3 — has been the most contested part of the tax system since the Supreme Court's 2021 Kerstarrest. Five years on, the system is still a temporary patch waiting for a real reform. If you have savings, investments, crypto, or a second property, here's what's different in 2026 — in plain language.
Key takeaways
- The tax-free allowance in Box 3 stays at €57,000 per person (€114,000 for fiscal partners).
- The flat tax rate on the deemed return is 36% — unchanged from 2025.
- The deemed return on "other assets" (stocks, crypto, real estate) increases slightly, while the savings rate is recalculated based on actual interest rates.
- The promised actual-return system has been postponed again. The government now targets 2028.
- If your real return was lower than the deemed return, you can still file for a counter-proof (tegenbewijsregeling).
What is Box 3 again?
Box 3 is the Dutch wealth tax. The Belastingdienst doesn't tax what you actually earned on your savings or investments. Instead, it assumes a fictitious return based on the type of assets you hold on January 1 (the peildatum), then taxes that fictitious return at a flat rate.
If you actually earned more than the assumed return, you got lucky. If you earned less — say, because the stock market was flat — you still pay tax on a return you never received. That's the controversy in one sentence.
What actually changes in 2026
Three things matter for the 2026 tax year:
- The savings yield is recalibrated. Each year, the deemed return on bank deposits is set close to actual savings interest rates. With ECB rates declining through 2025, expect a lower savings yield than last year.
- The "other assets" yield ticks up. Stocks, bonds, crypto, and rental property all sit in this bucket. The percentage moved slightly higher than 2025 — meaning more tax for portfolio investors.
- The 36% flat rate stays. Coalition talks earlier this year floated a hike to 37–38%. That didn't happen — for now.
Good to know
The exact 2026 percentages are published by the Belastingdienst each spring once the previous year's interest data is final. Always cross-check with the official rate sheet before you file.
Who feels this most
| Profile | Impact in 2026 |
|---|---|
| Pure savers (cash, no investments) | Slightly lower Box 3 bill if the savings yield drops |
| Investors (stocks, ETFs, crypto) | Slightly higher bill — the "other assets" yield rises |
| Mixed portfolios | Roughly flat — savings drop offsets investment increase |
| Property investors (non-primary home) | Highest impact — rental property is in Box 3 at the full investment yield |
What about the tegenbewijsregeling?
This is the most overlooked rule of the past two years. If your actual return was lower than the deemed return, you can submit counter-proof and pay tax on the real number instead.
You qualify if:
- Your actual total return (interest + dividends + realised and unrealised gains) was lower than the fictitious return calculated by the Belastingdienst.
- You can document it — bank statements, broker reports, valuation snapshots on January 1 and December 31.
The form is called Opgaaf werkelijk rendement. It's available in your account on Mijn Belastingdienst. The process is fiddly but real money is at stake — for portfolios that lost value in a given year, this can wipe out the Box 3 bill entirely.
What about 2028 — when does the real reform arrive?
The new system will tax actual returns: realised gains, dividends, interest, rental income. Unrealised gains on certain assets (notably real estate) may be taxed too, on a "mark-to-market" basis. The bill is now expected to be debated in 2026–2027 and take effect on January 1, 2028 — a year later than the previous target.
If you're making long-term decisions today, plan for a transition where:
- Real estate outside your primary home becomes more painful to hold.
- Buy-and-hold investing becomes relatively less tax-efficient (because unrealised gains might be taxed).
- Pension contributions (Box 1 deduction) become more attractive relative to private investing.
Three things to do before your next return
- Snapshot your assets on January 1, 2026. Bank balances, brokerage account values, crypto wallet values, WOZ value of any second property. The Belastingdienst will check the date.
- Track your real return through the year. If it ends up below the deemed return, you'll want to file Opgaaf werkelijk rendement. Keep statements organised.
- Use the tax-free allowance fully. Couples often forget to split assets so both partners use their €57,000 allowance — that's €114,000 sheltered if you do it right.
Warning
This article is general information, not personal tax advice. Box 3 has many edge cases — green investments, debts, joint property, the 30% ruling's partial non-resident status. When in doubt, talk to a belastingadviseur.
Want to estimate your 2026 Box 3 bill?
We've built a free Box 3 calculator that uses the latest deemed-return percentages. Plug in your savings, investments, and debts to see your estimated bill — and how much the tegenbewijsregeling could save you.