How the Netherlands taxes your 401k

How does the Netherlands tax a 401(k)?

The Netherlands taxes your 401(k) at two moments, not one. While the pot grows, the question is which box it belongs in. When money comes out, the question is which country may tax it. We explain both and we say where an advisor still has to confirm.

This guide is for you if you live in the Netherlands and hold a US retirement account. It covers the 401(k) and the Traditional IRA from years worked in the US. It does not cover Roth accounts or your US filing duties. Do you have a Roth account? Read our page on the Roth IRA in the Netherlands first.

Ellen moved from Seattle to Groningen eleven years ago and now teaches at a research institute. She still holds a 401(k) worth about $210,000. We follow her account through every rule on this page, starting with the five points that matter most.

Do you pay Dutch tax while your 401(k) grows?

Most likely not, if the Netherlands treats your pot as a pension right. Ellen's account has sat untouched for eleven years, so this is her first question. A pension right is not part of your Box 3 wealth, so its value stays outside the yearly calculation. An ordinary US investment account would sit in Box 3, which is exactly why the label matters.

The Belastingdienst looks at what the account really does, not at its name. You put money into a 401(k) or a Traditional IRA before US tax. That untaxed build-up is what points towards pension treatment here. We confirm this per account before you file, because the answer changes what you owe.

The table below sets out the four situations we see most often.

You still report the account in your Dutch return.

What if part of it does land in Box 3?

Then the Netherlands applies a set return in 2026, taxed at 36%¹. Not every US account earns pension status. Box 3 does not use your real return. It applies a standard percentage per category, called a deemed return. Our page on assets in Box 3 works through that calculation.

The 2026 figures are in the table below.

Box 3 looks at the value of your account on 1 January.

Who taxes the money when it comes out?

The Netherlands taxes the payout as Box 1 income. So what happens on the day the first payment lands? The Netherlands and the United States have a tax treaty that decides which country may tax a pension payment. The treaty also lets the United States keep taxing its own citizens wherever they live. Tax treaties call that rule the saving clause.

The practical effect is that both countries can have a claim on the same payment. The treaty then decides which country gives way. The Netherlands grants relief for the part that belongs to the other one. We name the exact articles only once an advisor has checked them against your account.

Our page on a foreign pension in the Netherlands covers the general rules for a non-US pension. The rate you pay on that income follows the tax brackets for pensioners.

One boundary matters before you go further.

What does this mean for Ellen?

Her pot stays outside Box 3 until it pays out. Ellen now has the two rules she needs, so we can walk her account through them. While the pot stays untouched, the balance itself does not enter her Box 3 calculation. Her savings and her investments are the only wealth she declares.

When she starts drawing on the pot, each payment becomes Box 1 income in the Netherlands. The treaty settles what the United States may still take. Ellen then claims relief in her Dutch return for that part. We do not put a euro figure on her outcome. Her advisor has to sign off the rules behind that figure first.

One move can undo all of it.

What changes when Box 3 moves to actual return?

Little changes for a pot that sits outside Box 3. The Netherlands is expected to tax Box 3 on the return you actually make. Our page on the Box 3 reform follows that timeline. The change matters most if part of your US money sits in an ordinary account without pension status.

Our advisor puts the practical rule plainly.

What should you check before your next return?

Start with what the account actually does. Ellen's position turned on how her account works, not on its name. Yours will too. Ask your provider for the plan type and the contribution history. Then have an advisor confirm which Dutch box it belongs in.

If you expect a payout soon, get the treaty position in writing before the first payment leaves the US. You can also ask the Belastingdienst to confirm its position in advance. The Dutch call that zekerheid vooraf. It takes time, so start well before you file.

We can also take that step with you, alongside your Dutch return. Ellen takes the same step, confirm the box first, then plan the payout.

How this fits your wider pension plan is on our page about pension advice.