What does it mean?
Based on a Surpreme Court decision (in fact 2 decisions), the deemed Box 3 result is sometimes considered as unfair. Therefore you can share the actual result with the Dutch tax authorities, which may lead to a reduced tax liability (and a tax refund if you already paid the higher amount in tax) if your actual result from investments was less than the deemed result. 

What information needs to be submitted?
For actual result, apart from interest, dividend, rental income and exchange rate proceeds, also the (un)capitalized gain/loss is considered. Detailed information on which elements of actual income need to be provided to the Dutch tax authorities can be found here.

What is to gain?
Your deemed result from savings and investments (wealth based - Box 3 method) is mentioned on page 2 of the letter. The applicable tax rate on income from savings and investments was as follows:

Tax rate 2021 and 2022 = 31%
Tax rate 2023 = 32%
Tax rate 2024 and 2025 = 36%

How to proceed / plan of action
If your actual result from investments (including uncapitalized gain/loss) was more than the deemed result, you do not need to do anything. Action is only required if the Box 3 method lead to disadvantage in the taxation.

So, if the actual result from your investments was smaller than the deemed (Box 3) result that is mentioned in the letter, you can follow the below steps.

Step 1: determine the maximum benefit
If you take the amount mentioned in the letter and apply the applicable tax rate for the year to get to the maximum gain for you. If your deemed income from savings and investments was not too high, you may want to leave it or proceed by yourself, because it may not be worth it to get a consultant involved considering the fact that a professional tax consultant will easily be occupied for 1-2 hours (@ € 200 or more) explaining, checking data and filing the actual result information. 

Step 2: check how your wealth was divided (savings/investments)
If you mostly had savings (not much stocks/shares, claims, crypto, investment property and other investments), it is likely that the deemed result was quite close to or even more beneficial than the actual result. In that case you can proceed to step 3, but chances are that reporting the actual result will not lead to (much) gain.

Step 3: go to Belastingdient.nl
Find the blue box regarding "Box 3: brief gekregen om uw werkelijk rendement door te geven?" and click on > Vul het formulier in

Follow the steps to see which information needs to be submitted and make sure that you can provide proof in case requested. 




Limited to no benefit situations
If the actual result > deemed result, you do not need to do anything. In case the deemed result is limited, you should determine whether it is worth the effort. Take in mind that the larger the wealth portion is that you have in savings, the smaller the impact of poor result on investments.

Possible benefit situations
If the deemed income in the letter is substantial and part of your wealth was invested and performed under the deemed investment rate that the Dutch tax authorities applied in the concerning year, it is likely that reporting the actual result leads to a more beneficial result. Obviously, the total amount of deemed income and the ratio of wealth in savings vs wealth in investments play a role in the potential benefit.

Highly likely gain situations
If you had a bad investment year, where your investment clearly lost more value (uncapitalized loss) than you had in income, it is highly likely that reporting the actual result from your investments will lead to a more beneficial taxable income from savings and investments. This could apply if the value of stocks went down, but also crypto for example. Maybe the most unpredictable wealth item is Dutch real estate, where the value of Box 3 often fluctuates. 


More background details on the history of Box 3 taxation, can be found here.