Foreign residents in Spain: new tax obligation for 2026 that may affect your tax return

The Spanish Tax Authority intensifies control over foreign residents in 2026. Modelo 720, international income and automatic data cross-referencing: there are no grey areas left for those with assets outside Spain.

Published on 2026-03-25 · GTM Team

The Spanish Tax Authority has confirmed that in 2026 it is intensifying tax control over foreign residents, especially those with assets outside Spain —and this has real implications for both income tax returns and the Modelo 720.

This is not a rumour: it's a practical reality already shaping the tax calendar.

📌 What is changing

From this year, the Tax Authority is applying more rigorously:

👉 the obligation to declare assets and rights abroad

👉 full taxation of residents, with no exceptions or "grey areas"

This specifically affects:

📊 Modelo 720: what you need to know now

Modelo 720 remains mandatory for those who have:

The important thing now is:

👉 The Tax Authority cross-references this data with other countries via tax agreements

If you don't file Modelo 720 or file it late, penalties are no longer considered void by default, as happened years ago. They are now real and enforceable, according to several recent Supreme Court rulings and changes in administrative interpretation.

This means:

💡 Taxation of international income

If you are a tax resident in Spain, your taxation is global:

And here is the tax trap that many foreigners don't see:

👉 even if you've already paid taxes abroad, Spain can claim the difference if the rate there is lower.

The famous double taxation tax credits help… but they don't eliminate the obligation to declare and justify everything.

⚠️ Be careful with rental properties abroad

Many foreign residents believe that if the property is outside Spain, it doesn't need to be declared.

Wrong.

👉 If you are a tax resident in Spain, rental income from a property abroad is also taxed in Spain

It is computed as real estate capital income with rules similar to domestic properties.

If you also pay taxes abroad:

🧠 The increase in international data cross-referencing

Here's what few explain well:

Europe and Spain are exchanging billions of tax data points through:

This means:

👉 The Tax Authority already knows what you have abroad, even before you declare it.

📌 Conclusion

Being a foreign resident in Spain is no longer the same as it was a few years ago.

Before:

Now:

👉 There are no grey areas

👉 The Tax Authority cross-references data automatically

👉 A tax advisor is no longer optional… it's essential

And the worst part:

👉 mistakes no longer fix themselves — they generate penalties.

Sources