What is the Netherlands Box 3 tax and who does it affect?

Box 3 is the Dutch tax on savings and investments. Lawmakers want to shift it to actual annual returns from 2028. It mainly affects Dutch tax residents. Some non-residents could be taxed on Dutch-situs assets, like property, depending on treaty rules. Canadians should verify residency and asset location.

Will the Netherlands Box 3 tax apply to unrealized gains?

It is under debate. Policymakers are considering taxing actual yearly returns, which could include unrealized gains for certain assets valued at year-end. Design choices, like carve-outs and loss offsets, are not final. The decision expected around March 15 will clarify scope and mechanics.

How would the 36% rate be applied under Box 3 reform?

The current proposal uses a 36% levy on annual portfolio gains. The base could include dividends, interest, realized gains, and possibly unrealized gains, subject to final rules. Treatment of losses and special sectors remains contested, which will affect how the effective rate lands for different investors.

What should Canadian investors with Dutch assets do now?

Inventory Dutch-taxable holdings, track realized and unrealized gains, and model yearly cash needs for possible tax bills. Build a liquidity buffer, review distribution schedules, and prepare documentation of losses. Confirm residency and treaty positions with advisors, and watch for legislative updates before 2028 to adjust allocation plans.

Law and Government

January 18: Netherlands Box 3 Tax Debate Weighs Unrealized Gains

ByHuzaifa Zahoor January 19, 2026January 19, 2026

The Netherlands Box 3 tax is back in focus as lawmakers debate taxing actual annual returns, potentially including unrealized gains, from 2028. A 36% levy on yearly portfolio gains is on the table, with a March 15 deadline to avoid a €2.35 billion budget gap. For Canadian investors with Dutch assets, this wealth tax reform could affect allocation, liquidity, and timing of trades. We explain what may change, how it could work, and practical steps to prepare while the details are still under debate.