What is Box 3 and why should you object?
Box 3 is the Dutch wealth tax — a tax on your savings, investments, and other assets. The problem? The Belastingdienst assumes you earn a fictitious return (forfaitair rendement) on your wealth, even if your actual return was much lower.
Since the landmark Kerstarrest ruling by the Hoge Raad (Supreme Court) in December 2021, the old Box 3 system has been declared unlawful. If you paid more tax than you should have based on your actual returns, you can get money back.
Quick check
Use Bowie's Box 3 Calculator to instantly see if your forfait tax exceeds your actual tax — and by how much.
Who can file an objection?
You can object if:
- You had savings or investments in the years 2017–2025
- Your actual return (interest, dividends, capital gains) was lower than the fictitious return the Belastingdienst assumed
- You filed (or should have filed) a tax return for those years
Even if your return was negative (a loss), the Belastingdienst may still have taxed you on a positive fictitious return. That's money you can reclaim.
Deadlines you need to know
| Situation | Deadline |
|---|---|
| You just received your assessment (aanslag) | 6 weeks from the date on the letter |
| You missed the 6-week window | File a "verzoek ambtshalve vermindering" (up to 5 years back) |
| Mass objection years (2017–2022) | Automatically included if you filed on time |
Don't wait too long
For tax years 2023 and 2024, you must file your own individual objection. These are NOT automatically covered by the mass objection ruling.
How to calculate your potential refund
The key calculation is simple:
- Fictitious return — what the Belastingdienst assumed you earned (based on forfait rates)
- Actual return — what you really earned (interest + dividends + realized gains − losses)
- Difference — if fictitious > actual, you overpaid
Example
Let's say you had €200,000 in savings at 1.5% interest (€3,000 actual return), but the forfait assumed 6.04% on investments (€12,080 fictitious return).
- Overpaid forfait: €12,080 − €3,000 = €9,080
- Tax on the difference (at 36%): €3,269 potential refund
Step-by-step: filing your objection
Step 1: Gather your documents
You'll need:
- Your aanslag inkomstenbelasting (tax assessment) for the relevant year
- Bank statements showing your actual interest earned
- Brokerage statements showing dividends and capital gains/losses
- Your BSN (burgerservicenummer)
Step 2: Calculate the difference
Use Bowie's Box 3 Calculator to compare your forfait tax vs. actual tax. This gives you the exact amount to claim.
Step 3: Write your objection letter
Your objection (bezwaarschrift) must include:
- Your name, address, and BSN
- The date and number of the assessment you're objecting to
- A clear statement that you object to the Box 3 assessment
- The reason: your actual return was lower than the forfait return
- The amount you want refunded
- Your signature
Step 4: Submit your objection
You can submit via:
- Mijn Belastingdienst (online portal) — fastest option
- Post — send registered mail to your local belastingkantoor
- Phone — call the Belastingtelefoon at 0800-0543 (free)
Step 5: Wait for the decision
The Belastingdienst has up to 6 months to process your objection (they can extend by another 6 months). If approved, the refund is deposited directly into your bank account.
What if your objection is rejected?
If the Belastingdienst rejects your objection, you can:
- File an appeal (beroep) with the rechtbank within 6 weeks
- Escalate to the gerechtshof and ultimately the Hoge Raad
Given the Kerstarrest ruling, objections based on actual vs. forfait returns have a strong legal basis. Most are being approved.
Frequently asked questions
Do I need a tax advisor to file an objection?
No — you can do it yourself. Bowie's calculator gives you all the numbers you need. For complex situations (e.g., foreign assets), a tax advisor can help.
Can I object for multiple years at once?
Yes, but you need a separate objection for each tax year.
What about the new Box 3 system from 2027?
The Dutch government is introducing a new system based on actual returns. Until then, the current forfait system applies — and objections remain valid.
How much does it cost to object?
Nothing. Filing an objection is free. If you go to court (beroep), court fees apply (€50 for individuals).
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