Spain-US Tax Treaty: What American Expats in Spain Need to Know

Americans living in Spain face a unique and complex tax position. Unlike citizens of most other countries, US citizens are taxed by the United States on their worldwide income regardless of where they live — this is citizenship-based taxation, one of only two countries in the world (along with Eritrea) that applies this system. The Spain-US Tax Treaty of 1990 (with a 2013 Protocol) provides some relief, but its scope for US citizens is significantly limited by the treaty's "saving clause."

Treaty Overview: The 1990 Convention + 2013 Protocol

The Convenio entre el Reino de España y los Estados Unidos de América para Evitar la Doble Imposición (CDI España-EEUU) was signed in 1990 and substantially amended by a 2013 Protocol (see BOE full text). The treaty follows the OECD model but includes important departures, most notably in the estate tax article (Article 22) — one of the few US tax treaties to address inheritance and estate taxes.

The Saving Clause: Why the Treaty Helps Less Than You Think

Article 1(4) of the treaty contains the saving clause: the United States reserves the right to tax its citizens as if the treaty had not come into force. This means the treaty's benefits — particularly exemptions from tax or reduced withholding rates — generally apply to Spanish residents who are not US citizens. For US citizens resident in Spain, most treaty benefits are overridden by the saving clause.

The saving clause does not eliminate the treaty's usefulness for Americans, but it means that treaty protection must be evaluated article by article to determine whether a specific provision survives the saving clause. Treaty provisions for which the US specifically carves out saving clause exceptions (i.e., the treaty expressly says the saving clause does not override) remain available to US citizens.

US Citizenship-Based Taxation: The Fundamental Principle

Every US citizen — wherever they live — must file an annual US federal tax return (Form 1040) reporting worldwide income. This obligation exists regardless of whether any US tax is ultimately due. For Americans in Spain, the result is a dual filing obligation: both a Spanish IRPF return and a US Form 1040 are required each year.

The Foreign Earned Income Exclusion (FEIE — Form 2555)

The Foreign Earned Income Exclusion (IRC §911) allows qualifying Americans abroad to exclude foreign earned income — salary, wages, self-employment income — from US federal income tax, up to an annual limit. For 2024, the exclusion amount was $126,500 (indexed for inflation). To qualify for the FEIE, the taxpayer must meet either the bona fide residence test (established foreign residence) or the physical presence test (330 days outside the US in a consecutive 12-month period). Most Americans resident in Spain qualify under the bona fide residence test.

The FEIE reduces the US taxable income but does not reduce the Spanish IRPF liability. It is a US-side relief only. Income above the FEIE threshold remains subject to US tax (at the rates applicable to the taxpayer's marginal bracket above the exclusion amount).

The Foreign Tax Credit (FTC — Form 1116)

For income not excluded by the FEIE, the Foreign Tax Credit allows US citizens to credit Spanish IRPF paid against their US federal tax liability on the same income. The FTC is calculated separately by income category (general limitation basket, passive income basket, etc.) and is subject to complex limitation rules. In broad terms:

• Spanish IRPF paid on employment income (above the FEIE exclusion) offsets US tax on that income
• Spanish tax on investment income offsets US tax on the same income
• Excess FTCs can be carried back 1 year and forward 10 years
• The FEIE and FTC cannot both be applied to the same income — a taxpayer must choose which to use for earned income

Spain's high IRPF rates generally mean that Spanish tax exceeds the US tax liability on most income types for Americans in Spain. For many Americans in Spain, the net US federal tax after the FTC is zero — but the filing obligation remains.

Employment Income (Article 15)

Article 15 of the treaty allocates employment income to the country of work. For a US citizen employed in Spain, the salary is primarily taxable in Spain. The US taxes it too (under the saving clause), but the FTC eliminates most or all US liability on Spanish employment income above the FEIE amount.

The PFIC Problem

Passive Foreign Investment Companies (PFICs) under IRC §1297 are a serious concern for Americans in Spain. Any non-US collective investment vehicle — Spanish fondos de inversión, Irish-domiciled ETFs, Luxembourg SICAVs, and even the Spanish UCITS funds that offer the Art. 94 switching advantage — is likely a PFIC for US purposes. PFICs are subject to a punitive US tax regime:

• Excess distributions (distributions exceeding 125% of the prior 3-year average) are subject to interest charges calculated on a deferred tax basis
• Gains on PFIC shares are treated as excess distributions — also subject to the interest charge regime
• Annual reporting on Form 8621 is required for each PFIC held
• A QEF (Qualified Electing Fund) election or mark-to-market election can ameliorate the regime but requires the PFIC to provide annual PFIC Annual Information Statements — which most European funds do not

The practical result: Americans in Spain are effectively restricted to US-domiciled investment vehicles (US ETFs, US mutual funds) to avoid PFIC consequences. EU PRIIPs regulations, however, restrict the availability of US funds to European investors, creating a significant practical problem. Professional advice is essential.

Social Security Totalization Agreement

Separately from the tax treaty, the US and Spain have a Social Security Totalization Agreement that prevents workers from being required to pay into both the US Social Security system and the Spanish Social Security system simultaneously. Under the agreement, employees generally pay into the system of the country where they work. Self-employed individuals may elect into one system based on their circumstances.

Estate Tax: Article 22 — One of the Few US Treaties Covering Estates

The Spain-US treaty includes an estate and gift tax article (Article 22) — one of a relatively small number of US tax treaties to cover inheritance and estate taxes. The article provides for the reduction of double taxation on estates where the decedent was a US citizen resident in Spain. The US estate tax applies to the worldwide assets of US citizens regardless of domicile; Spain's ISD applies on assets of Spanish-domiciled decedents. Article 22 provides credits and allocation rules to reduce double taxation, though the interaction is complex.

FBAR and FATCA: The Reporting Obligations

Beyond tax filing, Americans in Spain face two additional reporting obligations:

• FBAR (FinCEN Form 114): Filed annually with the US Treasury (not IRS) if the aggregate value of all foreign financial accounts exceeds $10,000 at any point during the year. Spanish bank accounts, brokerage accounts, and UCITS fund accounts held at Spanish institutions all count. Penalties for non-filing are severe ($10,000 per non-wilful violation; up to $100,000 or 50% of account value for wilful violations).
• Form 8938 (FATCA): Filed with the IRS as part of Form 1040 if specified foreign financial assets exceed $200,000 at year-end (or $300,000 at any point during the year) for Americans living abroad. Higher thresholds than FBAR, but broader asset coverage (includes foreign entity ownership, foreign insurance policies with cash value, foreign pension plans).