Spanish real estate and Box 3: direct ownership or project participation

Spanish real estate and Box 3 are often lumped together, even though the tax treatment depends entirely on the form in which you participate. A property held in your own name in Marbella is treated differently than a claim on a Spanish project company, even if the underlying real estate is identical. That difference determines whether or not the Netherlands grants relief for double taxation.

This page outlines the main points: how Box 3 works in 2026, what the tax treaty with Spain regulates, what Spain itself levies, and why participating in a project follows a different tax route than direct ownership. This is an explanation of the system, not advice regarding your own situation.

How Box 3 works in 2026

Box 3 taxes a deemed return on your assets, not your actual yield. The Tax and Customs Administration categorizes assets and applies a fixed percentage to each category.

The following principles apply for 2026:

• For other assets, the category that includes real estate and receivables, a fixed return of 6.00 percent is applied.
• A tax rate of 36 percent applies to the calculated return.
• The tax-free allowance is 59,357 euros per person, and 118,714 euros for tax partners.

On assets of 1,000,000 euros in other assets, the levy amounts to approximately 20,000 euros per year, before taking into account the tax-free allowance and relief for double taxation.

The counter-evidence scheme

Since the Box 3 Counter-Evidence Scheme Act, you can demonstrate that your actual return was lower than the fixed rate. If successful, the tax is calculated based on the lower actual return.

This is relevant for project-based real estate because the return there is not spread evenly over the years. During renovation years, there is usually no income, while the fixed rate continues to apply. The result is only realized in the year of sale. Those who provide counter-evidence in the intervening years pay tax on a lower amount in those years. How this works out in your case depends on the composition of your entire Box 3 asset base.

Direct ownership of Spanish real estate

If you own a Spanish property in your own name, its value counts towards your Dutch Box 3 assets. At the same time, Spain is permitted to tax that property because the tax treaty between the Netherlands and Spain assigns the right to tax real estate to the country where the property is located.

The Netherlands provides relief for double taxation for this via the proportional exemption method. In practice, this means that while the Spanish real estate is included in determining the tax base, the portion allocated to Spain is exempted. The Netherlands applies a progression reservation: the foreign property is taken into account when determining the tax on the remaining Box 3 assets.

What Spain itself levies

On the Spanish side, two levies play a role for non-residents.

• Income tax for non-residents, the IRNR. If you do not rent out the property, Spain calculates a notional income based on the cadastral value. If you do rent it out, the actual rental income is taxed.
• Wealth tax, the Impuesto sobre el Patrimonio. As a non-resident, you only pay this on your Spanish assets, and only above an exemption of 700,000 euros per person. In 2026, this extended exemption will continue to apply in full to non-residents.

In Andalusia, which includes the Costa del Sol, a regional discount of 100 percent applies to wealth tax. As a result, the majority of investors there effectively pay nothing in regional tax. However, the national solidarity tax for large fortunes of 3 million euros or more applies throughout Spain, with rates ranging from 1.7 to 3.5 percent.

Participation in a project follows a different route

If you do not own the real estate yourself but participate in a project, the nature of your asset changes. You do not hold real estate, but a claim on a company or an interest in that company. As described in the legal structure of a Spanish S.L., the company itself is the owner of the property.

That distinction has consequences. A claim on a Spanish company is not considered real estate under the treaty. The right to tax it lies, in principle, with your country of residence, i.e., the Netherlands. In Box 3, such a claim falls under other assets, at the same fixed rate of 6.00 percent, but without the relief you would receive for direct ownership.

On the other hand, you generally remain outside the scope of the IRNR and Spanish wealth tax on the Spanish side, as you do not hold Spanish real estate. Whether this works out more or less favorably on balance depends on your total asset position, the size of your other Box 3 assets, and whether the counter-evidence scheme offers a solution in your case. That is precisely the kind of assessment you should make with your own advisor rather than deriving it from a general article.

A calculation example for illustration

Suppose you invest 250,000 euros and the tax-free allowance has already been used up by other assets.

In Box 3, a deemed return of 6.00 percent is used, which is 15,000 euros. A 36 percent tax on this results in a levy of 5,400 euros per year.

With an indicative fixed return of 8 percent, the gross yield is 20,000 euros. After the Box 3 levy, an indicative 14,600 euros remains, or approximately 5.8 percent net. With a return of 10 percent, this comes to approximately 7.8 percent net.

This example deliberately ignores your other assets, the counter-evidence scheme, and any potential Spanish taxes. The percentages mentioned are indications and not commitments. Past results are no guarantee of future performance.

Common mistakes

Four misconceptions consistently recur in conversations with investors.

• Assuming that every form of Spanish real estate qualifies for the prevention of double taxation. This applies to direct ownership, but not automatically to a receivable or an interest.
• Taking Spanish wealth tax for granted. In Andalusia, the regional levy is fully offset, but the national solidarity tax remains in effect for amounts over 3 million euros.
• Confusing the 6.00 percent fixed rate with an expected return. It is a calculation rule, not a forecast.
• Considering the rebuttal scheme only at the time of assessment instead of when setting up the structure.

Frequently asked questions

Do I have to file a tax return in Spain if I only participate in a project?

If you do not hold Spanish real estate and are not a Spanish resident, there is generally no filing obligation for the IRNR. However, Spain may withhold tax on dividends or interest from a Spanish company. Have this checked for your specific situation.

Does a participation count towards the tax-free allowance?

Yes. The tax-free allowance of 59,357 euros per person applies to your total Box 3 assets, regardless of their composition.

What happens fiscally in the year of sale?

Under the deemed return system, it is not the profit itself that is taxed, but the deemed return on the value as of the reference date. When applying the counter-evidence scheme, the actual result is taken into account, which may result in a higher tax burden in the year of sale compared to the intervening years.

Is a structure via a holding company more favorable?

If you hold the participation through a company, the tax shifts from Box 3 to corporate income tax and later to Box 2. Whether that is more advantageous depends on the size, the duration, and what you intend to do with the proceeds. This requires an individual calculation.

Is anything changing regarding Box 3?

The system has been adjusted several times in recent years, and the transition to taxing actual returns has not yet been completed. Please keep in mind that the percentages and the system may change during the term of a project.

Can I offset Spanish taxes against my Dutch tax assessment?

For direct ownership, the Netherlands provides relief through proportional exemption. For other forms of participation, the process differs. The outcome depends on the type of income and the applicable treaty provisions.

Next steps

The tax outcome of an investment in Spanish real estate is determined by its structure, not by the rate of return. Those who choose the structure after the return has been promised will only discover the tax consequences upon receiving their assessment.

Would you like to see how a specific project proposal is structured, including the legal form and cash flows per phase? Schedule a personal appointment.

This article is general in nature and does not constitute legal or tax advice.