The United States and Spain have a comprehensive income tax treaty and a social security totalization agreement in force. For most US citizens living in Spain, this framework, combined with the US Foreign Tax Credit, typically eliminates double taxation on most income. However, US tax compliance remains complex due to specific rules for Spanish pensions, investments, and business ownership.
US filing basics every American abroad must know
US citizens and green-card holders are taxed on worldwide income wherever they live, and usually must file Form 1040 once gross income exceeds the IRS threshold (roughly $15,000 to $30,000 depending on filing status for recent years), even when no tax is ultimately due. The tools that prevent double taxation are the Foreign Earned Income Exclusion (FEIE, up to $130,000 for 2025 under IRC §911) and the Foreign Tax Credit.
Two reporting rules catch most filers in Spain: the FBAR (FinCEN Form 114), required when foreign financial accounts exceed $10,000 in aggregate at any point in the year, and Form 8938 (FATCA) for specified foreign assets above the applicable threshold. Both can carry penalties even when no tax is owed. If you are behind, the Streamlined Filing Compliance Procedures are the usual penalty-free path back for non-willful taxpayers.
US tax treaty with Spain
The current US-Spain income tax treaty consists of the original agreement signed in 1990 and a subsequent protocol that entered into force in 2019. The treaty's primary function for most US citizens is to reduce withholding taxes on cross-border income and provide rules to determine tax residency. It contains a 'saving clause' (Article 1, Paragraph 4) which reserves the right for the US to tax its citizens as if the treaty did not exist. Therefore, US citizens in Spain must still report their worldwide income to the IRS and rely on mechanisms like the Foreign Tax Credit, rather than the treaty itself, to avoid double taxation.
Article 10 (Dividends).
Reduces the withholding tax on dividends paid from a source in one country to a resident of the other. The general cap is 15%, with lower rates for certain corporate and pension fund owners.
Article 11 (Interest).
Eliminates source-country withholding tax on interest payments, meaning interest flowing between the US and Spain is generally only taxable in the recipient's country of residence.
Article 12 (Royalties).
Eliminates source-country withholding tax on royalties, allowing royalties to be taxed only in the recipient's country of residence.
Article 1(4) (Saving Clause).
The saving clause allows the US to tax its citizens and residents on their worldwide income according to its domestic laws, regardless of most treaty provisions. This is a standard feature in US tax treaties and is the reason US citizens abroad must still file US tax returns.
| Income type | Treaty rate | Statutory rate | Notes |
|---|---|---|---|
| Dividends | 15% | 30% | 5% for companies owning at least 10% of the paying company's voting stock; 0% for qualifying pension funds or corporate parents with at least 80% ownership for 12+ months. |
| Interest | 0% | 30% | |
| Royalties | 0% | 30% |
Because of the saving clause, a US citizen generally cannot use the treaty to exempt income from US tax; it mainly supports reduced withholding on investment income and supplies tie-breaker rules for determining tax residency.
Spanish Pensions and US Tax
Spain's pension system has three pillars, and the US tax treatment of occupational (Pillar 2) and private (Pillar 3) plans is highly complex. From a US perspective, Spanish plans like planes de pensiones are not 'qualified' in the same way as a 401(k).
This non-qualified status has several critical consequences for US persons:
- Reporting Requirements: The value of these pension accounts must be included when determining filing obligations for the FBAR (FinCEN Form 114) if aggregate foreign financial accounts exceed $10,000, and for FATCA (Form 8938) if specified foreign financial assets exceed thresholds (e.g., $200,000 for a single filer abroad).
- Foreign Trust Treatment: The IRS may treat these plans as foreign trusts, which could trigger annual reporting on Form 3520 and 3520-A. While Revenue Procedure 2020-17 provides a reporting exemption for certain employment-based plans, the conditions must be carefully reviewed.
- PFIC Issues: The underlying investments within Pillar 2 and 3 plans, such as foreign mutual funds, are almost always considered Passive Foreign Investment Companies (PFICs) by the IRS. This triggers a burdensome and potentially punitive tax regime, requiring annual filing of Form 8621 for each individual PFIC investment.
Investments, property, and capital gains in Spain
US persons investing in Spanish funds, such as mutual funds or ETFs, will almost certainly hold Passive Foreign Investment Companies (PFICs). This requires filing Form 8621 for each fund and navigating a complex and often punitive tax regime. Under the treaty, capital gains from the sale of personal property like stocks are generally taxable only in the country of residence. For a US citizen resident in Spain, this means Spain has the primary right to tax gains from the sale of US stocks, though the gain must still be reported on the US return where the Foreign Tax Credit can be used to prevent double taxation.
Ownership of a Spanish limited liability company (Sociedad Limitada or S.L.) also has major US tax implications. If US persons own more than 50% of the company, it becomes a Controlled Foreign Corporation (CFC). A US shareholder in a CFC must file Form 5471 annually and may be subject to current US tax on the company's profits under the Global Intangible Low-Taxed Income (GILTI) regime, even if no profits are distributed. While Spain's 25% corporate tax rate may be high enough to qualify for the GILTI high-tax exception, the complex reporting on Form 5471 is still required.
Self-employment and companies in Spain
A US-Spain Social Security (Totalization) Agreement is in force, which is highly beneficial for self-employed US citizens in Spain (known as autónomos). This agreement prevents double social security taxation. An autónomo who is properly registered and paying into the Spanish social security system can obtain a Certificate of Coverage from the Spanish authorities. This certificate serves as proof of exemption from paying US self-employment taxes (both the Social Security and Medicare portions) on their self-employment income. The income itself is still subject to US income tax, against which Spanish income taxes paid can be credited.
Worked examples
Salaried employee in Madrid (2025)
Maria, a US citizen, works as a marketing manager for a Spanish company in Madrid, earning a salary of €90,000 (approximately $99,000). She pays Spanish income and social taxes totaling around €25,000. On her US tax return, she reports her salary and can claim a Foreign Tax Credit for the €25,000 in Spanish taxes paid. Since her Spanish tax liability is significantly higher than the US tax would be on the same income (e.g., roughly $15,000), the credit reduces her US tax liability to zero. Alternatively, she could use the Foreign Earned Income Exclusion to exclude her $99,000 salary, also resulting in zero US income tax.
Self-employed consultant in Barcelona (2025)
John, a US citizen, is a self-employed graphic designer (autónomo) living in Barcelona. He earns €75,000 (approximately $82,500) in net self-employment income. Because he is fully integrated into Spain's social security system, he obtains a Certificate of Coverage from the Spanish authorities. This certificate exempts him from paying the 15.3% US self-employment tax on his earnings, saving him approximately $12,622 for the year. He still must file a US income tax return to report the income and uses the Foreign Tax Credit to offset his US income tax liability with the Spanish income taxes he paid.
Business owner of a Spanish S.L. (2025)
David, a US citizen, owns 100% of a Spanish S.L. that provides IT consulting. The company earns a profit of €150,000 and pays the Spanish corporate tax rate of 25% (€37,500). Because David owns more than 50% of the company, it is a Controlled Foreign Corporation (CFC). He must file Form 5471 with his US tax return. The company's profit could be subject to the GILTI regime. However, because the Spanish corporate tax rate (25%) is greater than 90% of the US corporate rate (18.9%), he can likely make a high-tax exception election to eliminate any current US tax liability under GILTI. Despite no tax being due, the Form 5471 filing is mandatory and highly complex.
Common mistakes for Americans in Spain
- Assuming the US-Spain tax treaty eliminates the need to file a US tax return.
- Forgetting to report Spanish pension accounts on the FBAR (FinCEN Form 114) and Form 8938.
- Treating Spanish mutual funds or pension investments as simple stocks, thereby failing to file Form 8621 for PFICs.
- US business owners failing to file Form 5471 for their Spanish S.L., mistakenly believing it's only for large corporations.
- Self-employed individuals (autónomos) unnecessarily paying US self-employment tax because they didn't obtain a Certificate of Coverage from Spain.
- Assuming a Spanish 'plan de pensiones' is a 'qualified' retirement plan like a US 401(k), leading to incorrect reporting of contributions and growth.
- Misinterpreting the saving clause and believing treaty articles on income sourcing will automatically reduce their US tax bill.
- Ignoring potential GILTI income from a Controlled Foreign Corporation (CFC), even if no dividends were paid out.
Spain tax FAQ
As a US citizen in Spain, do I still have to file US taxes?
Yes. US citizens are taxed on worldwide income and must file a US tax return annually, regardless of where they live. However, tools like the Foreign Tax Credit and Foreign Earned Income Exclusion usually prevent double taxation.
What does the US-Spain Social Security Agreement do?
It prevents double social security taxation. A worker, including a self-employed autónomo, generally pays into only one country's system. A US citizen covered by Spain's system can get a Certificate of Coverage to prove their exemption from US Social Security and Medicare taxes.
Is my Spanish pension taxable in the US?
Yes, it is generally subject to US tax. Spanish pension plans are not 'qualified' under IRS rules. The underlying investments are often PFICs, requiring complex reporting on Form 8621. The account value must also be considered for FBAR and Form 8938 reporting.
I own a small Spanish company (S.L.). Are there special US reporting rules?
Yes. If you are a US person who owns 10% or more of a Spanish S.L. that is majority-owned by US persons, it is likely a Controlled Foreign Corporation (CFC). This requires filing the complex Form 5471 annually and may subject you to US tax on the company's profits under the GILTI rules, even if you take no distributions.
What is a PFIC and why is it a problem for expats?
A Passive Foreign Investment Company (PFIC) is a foreign corporation with mostly passive income or assets. Most non-US mutual funds, ETFs, and investment funds inside Spanish pensions are PFICs. The default US tax rules for PFICs are extremely punitive, and annual reporting on Form 8621 is required for each one.
How does the tax treaty reduce withholding tax on my US investments?
The treaty lowers the default 30% US withholding tax on payments to foreign residents. For a resident of Spain, the rate on dividends from US stocks is reduced to 15% (or less in some cases), and the rate on interest is reduced to 0%.
Can I use the treaty to say my Spanish salary is not taxable in the US?
No, due to the 'saving clause.' The treaty allows the US to continue taxing its citizens on their worldwide income. You cannot use the treaty to exempt your earned income from US tax. Instead, you must use the Foreign Tax Credit or the Foreign Earned Income Exclusion on your US tax return.
What is the difference between the FBAR and Form 8938?
Both forms report foreign financial assets, but they are filed with different agencies and have different thresholds. The FBAR (FinCEN Form 114) is filed with the Treasury's Financial Crimes Enforcement Network if the aggregate value of foreign accounts exceeds $10,000. Form 8938 is filed with the IRS as part of your tax return if your specified foreign assets exceed higher thresholds (starting at $200,000 for a single filer abroad). An asset may need to be reported on both forms.
Sources and last reviewed
- IRS, Spain tax treaty documents (verified 2026-06-07)
- SSA, US-Spain totalization agreement (verified 2026-06-07)
- IRS, Comparison of Form 8938 and FBAR Requirements (verified 2026-06-07)
- Agencia Tributaria (Spanish Tax Agency) (verified 2026-06-07)
Last reviewed 2026-06-07.