Forfaitair rendement and fictief rendement in Dutch Box 3 tax: the difference

In Dutch income tax law, forfaitair rendement has been the official term since 2017 for the fixed percentage on which you pay Box 3 tax; before 2017 this was called fictief rendement, a name the Dutch Tax Administration (Belastingdienst) still uses interchangeably with forfaitair rendement on its own website. Separately, there is a completely different fictief rendement of 5.5% for substantial-interest holders in a tax-exempt investment institution (VBI), automatically linked since 2017 to the highest Box 3 percentage. For 2026, the ordinary deemed return on investments is 6.00%, rising to 6.37% in 2027; the tax-free allowance for 2027 had not yet been published at the time of writing. These figures apply only to the Dutch tax return.

This article explains Dutch Box 3 tax terminology and figures. It is not tax advice — the rules and percentages below apply only to Dutch income tax; if you live or are taxed elsewhere, different rules apply. Always check the current percentages and your personal situation with the Belastingdienst (the Dutch Tax Administration) or a tax advisor before making decisions based on it.

Forfaitair rendement and fictief rendement: two names for (almost) the same thing

Up to and including 2016, Box 3 had a single fixed percentage: a 4% fictief rendement on your entire wealth above the allowance, regardless of whether you held savings or investments. Since the 2017 reform, this percentage is set per wealth category: bank balances, other assets (including investments) and debts each get their own percentage. Since that reform, the legislator officially refers to forfaitair rendement rather than fictief rendement.

In practice, that distinction is less sharp than it looks: the Belastingdienst’s own website still uses questions like “met welke percentages is het fictief rendement berekend” (with which percentages is the fictief rendement calculated) for exactly the same concept. Confusing? Fair enough — even the Belastingdienst itself mixes up the terms. We find it, at the very least, confusing that the tax authority still uses the old term years after the reform, for anyone trying to make sense of their return. For the ordinary retail investor, forfaitair rendement and fictief rendement are therefore, in practice, synonyms for the same principle: your actual return does not count for tax purposes, but a percentage set in advance does. How that percentage then leads to a tax bill is worked out in the article on Dutch Box 3 tax and investing, including a worked example.

The percentages for 2026, and what’s already known for 2027

For the 2026 tax year, the following, final figures apply:

• Tax-free allowance: €59,357 per person (€118,714 for fiscal partners combined).
• Deemed return on other assets (shares, ETFs, bonds): 6.00%.
• Deemed return on bank balances: provisionally 1.44% (finalised only in early 2027).
• Deemed return on debts: provisionally 2.62% (also finalised only in early 2027).
• Tax rate: 36%.

On €150,000 in investments above the allowance, a 6.00% deemed return produces an assumed return of €9,000; you pay 36% tax on that, or €3,240 — regardless of what you actually earned. A common misconception: a lower deemed-return percentage doesn’t automatically mean less tax, because the tax-free allowance often changes over the same period.

For 2027, one figure is already fixed, because it is derived from return data from two years earlier: the deemed return on other assets rises to 6.37%. The percentages for bank balances and debts are based on more recent interest-rate data and are therefore only finalised later. FiscAlert cites a provisional indication of around 1.37% and 2.7% respectively. The tax rate is generally expected to remain unchanged at 36%, although proposals to lower it are circulating.

The tax-free allowance for 2027 had not yet been published at the time of writing (early September 2026). Not yet known, in other words. Waiting on Prinsjesdag. That amount is indexed annually and forms part of the Tax Plan (Belastingplan), which the cabinet presents on Prinsjesdag: this year on 15 September 2026, shortly after this article was published. For the definitive amount, always check the Belastingdienst itself.

As long as the “Wet werkelijk rendement box 3” has not come into force, this deemed-return system also remains in effect for 2027, for the Dutch tax return. Only from 1 January 2028 (if the Senate agrees) will the actual return achieved be taxed instead of a fixed percentage.

The exception: the fictief rendement of the 2017 VBI rule

There is another, entirely different “fictief rendement” that is unrelated to the Box 3 percentages above, and which had its own change specifically in 2017. This fictief rendement applies to holders of a substantial interest (usually 5% or more of the shares) in a tax-exempt investment institution (VBI): an investment vehicle exempt from corporate income tax, sometimes used by wealthy individuals with a substantial interest in their own company to move wealth from Box 3 into Box 2.

When a VBI distributes no or insufficient dividend in a given year, the Belastingdienst attributes a fictief rendement based on the intrinsic value of the shares, as a counterweight to simply deferring dividends to avoid tax. As of 1 January 2017, this percentage was raised from 4% to 5.5%, and has since been automatically linked to the highest deemed-return percentage that applies in Box 3 for other assets. The percentage therefore now moves in step with the ordinary Box 3 rates described above. This fictief rendement is then taxed at the substantial-interest rate in Box 2, not at the Box 3 rate.

This rule has nothing to do with an ordinary brokerage account. If you invest through such an account, you fall under the regular deemed-return regime from the previous section, not under this VBI exception, which is only relevant if you hold a substantial interest in a tax-exempt investment institution itself.

What this means for your return if you invest via DEGIRO

If you invest via DEGIRO, you almost certainly fall under the ordinary deemed-return regime for “other assets” above, not under the VBI exception. Under that regime, your actual result (see calculating your DEGIRO return) doesn’t change your Box 3 bill. For the precise value you need to enter on your Dutch tax return, including a common mistake with cash balances, see DEGIRO annual statement: data needed for your Dutch tax return. For the withholding tax already deducted from dividends received before you get to the Box 3 calculation, see Dividend tax on DEGIRO.

How ClearAnalyser helps with this

The compound interest simulator in ClearAnalyser accounts for Dutch Box 3 tax pressure when projecting your future wealth growth, giving you a more realistic picture than a simulation based on gross return alone. Which other trackers take Box 3 into account is covered in the DEGIRO portfolio tracker comparison.

Sources: Met welke percentages is het fictief rendement berekend in mijn aangifte? — Belastingdienst (Dutch) · Box 3 2027: forfaitair rendement beleggingen omhoog — FiscAlert (Dutch) · Regeling VBI en de verhoging van het forfaitair rendement per 2017 — BVDV (Dutch) · Forfait box 3 voor beleggingen in 2027 weer hoger — Fiscaal Rendement (Dutch) · Wet werkelijk rendement box 3 (bill, Rijksoverheid)