US Expat Taxes in Spain: FBAR, Treaty, and Totalization (2026)

The Double-Filing Reality for US Citizens

The United States is one of only two countries on earth (the other is Eritrea) that taxes its citizens on worldwide income regardless of where they live. If you are an American or green-card holder in Spain, you file a US federal tax return every year for the rest of your life, on top of whatever you owe Hacienda. The question is never "US or Spain?" — it is always both, and the craft lies in making sure you do not end up paying full freight to each.

The good news is that Spain and the US have a double-taxation treaty (1990, updated by a 2013 protocol that finally came into force in 2019), a totalization agreement for social security, and a well-developed credit mechanism. The bad news is that the treaty contains a savings clause that neutralises most of its protections for US citizens, leaving you to rely primarily on the Foreign Tax Credit and on careful account structuring.

Residence, the Treaty, and the Savings Clause

Once you meet Spain's domestic tax residency tests— 183 days, centre of economic interests, or family presumption — Spain taxes you on worldwide income. The treaty's residence tie-breaker (permanent home, centre of vital interests, habitual abode, nationality) resolves conflicts when both countries claim you. For most expats who have physically moved, the tie-breaker comes out Spanish.

But the treaty's savings clause (Article 1(3)) explicitly reserves the US right to tax its citizens as if the treaty did not exist, with a short list of carve-outs. The practical result: even if the treaty says Spain has the primary right on, say, your pension, the US still taxes you on it, and you rely on the Foreign Tax Credit to avoid paying twice. The treaty becomes a tool for determining which country gets the credit and which keeps the tax — not a tool for switching off US filing.

FBAR and FATCA: What Americans in Spain Must File

Two reporting regimes run alongside your US tax return and are the cause of more panic than the tax itself. FBAR— FinCEN Form 114 — must be filed every year if the aggregate value of your foreign financial accounts exceeded $10,000 at any point during the calendar year. "Foreign" means non-US; your Spanish bank account, your BBVA brokerage, a joint account with a Spanish spouse — all count. The threshold is aggregate and the test is "any point," so a single day above $10,000 triggers the full filing.

FATCA — Form 8938, attached to your 1040 — covers broadly the same accounts but at higher thresholds ($200,000 / $300,000 end-of-year / highest-point for a single filer resident abroad, doubled for joint filers). Penalties for non-filing are per-form, not per-account, and they are steep: civil penalties start at $10,000 for non-willful FBAR failures and escalate fast. Amnesty programmes (Streamlined Foreign Offshore Procedures) exist for people who missed years in good faith, and they are usually the right entry route if you have been in Spain for several years without filing.

Modelo 720 and 721: Spanish Side of the Same Problem

Spain has its own mirror regime. Once you are Spanish resident, Modelo 720 requires you to declare foreign accounts, foreign securities, and foreign real estate when any asset group exceeds €50,000, with Modelo 721 doing the same job for crypto held abroad. Your US Fidelity brokerage, your Vanguard IRA, your Bank of America checking account — all feed into Modelo 720 the same way they feed into FBAR and FATCA.

The practical implication is that Americans in Spain run three parallel informative regimes on the same underlying accounts. They do not substitute for each other. A failed Modelo 720 filing is punished on the Spanish side; a failed FBAR is punished on the US side; and the post-2022 Spanish penalty regime, while tamed by the CJEU ruling, is still real. Build one master spreadsheet of every foreign account and re-use it across all three.

FEIE vs Foreign Tax Credit: Picking the Right Tool

The US offers two main mechanisms to avoid double tax on earned income. The Foreign Earned Income Exclusion (FEIE, Form 2555) lets you exclude up to roughly $130,000 of foreign earned income per person per year, if you meet either the physical presence test (330 days abroad in a 12-month window) or the bona fide residence test. The Foreign Tax Credit (FTC, Form 1116) instead credits the foreign tax you actually paid against your US tax on the same income.

For Americans in Spain, FTC is almost always the better choice. Spanish income tax rates on earned income are materially higher than US federal rates, so the FTC typically wipes out the US bill and leaves you with unused credits you can carry forward ten years. FEIE, by contrast, is a deduction not a credit: it excludes income but does not generate credits, and stacking it with investment income often increases the US rate on the latter through the "stacking rule." For Beckham Law participants, the calculus can flip — Beckham's 24% flat rate on Spanish income is below US rates on higher earnings, and the FTC alone may not be enough.

Self-Employment and the Totalization Agreement

Self-employment is where Americans in Spain get blindsided. The FTC covers income tax, not self-employment tax (15.3% for Social Security and Medicare). Absent relief, a US freelancer in Spain would pay Spanish autónomo contributions and US SE tax on the same income. The Spain-US Totalization Agreement (1986) fixes this: it assigns social-security coverage to one country only, normally the country where you work.

In practice, if you are autónomo in Spain, you obtain a Spanish certificate of coverage and attach it to your US return, which exempts you from the 15.3% SE tax. The inverse — US-based contractors sent temporarily to Spain — works the same way in reverse, with a US CoC keeping them in the US system for up to five years. Get this wrong in either direction and you are paying social security twice with no credit path.

US Retirement Accounts: 401(k), IRA, Roth

Spain's treatment of US retirement accounts is one of the least settled areas of the treaty. Traditional 401(k) and IRA distributions are generally taxed in Spain when you are Spanish resident, at savings-base rates, with US tax creditable via the treaty. Pre-retirement withdrawals face the same Spanish tax plus any US early-withdrawal penalty, which is not creditable in Spain — the penalty is not a tax, so you eat it fully.

Roth IRAs are the harder case. The US treats qualifying Roth distributions as tax-free; Spain does not mirror the deferral and, depending on the interpretation, may tax the gain component of distributions as it accrues or as it is withdrawn. The position is unresolved enough that Spanish residents with large Roths sometimes delay distributions until returning to the US, or convert strategically before establishing Spanish residence. Do not assume "tax-free in the US" means "tax-free in Spain."

US Social Security in Spain

US Social Security benefits paid to Spanish residents are taxable in Spain under the treaty (Article 20), not in the US. The US stops its 25.5% default withholding on non-residents once you file Form W-8BEN with the Social Security Administration and receive a certificate of Spanish tax residence (Hacienda Modelo 2028). Spain then taxes the benefit at ordinary IRPF rates as pension income.

For those who have worked in both systems, totalization allows credits from one country to count toward qualifying for benefits in the other, without changing who pays. Nobody loses a pension by moving; people occasionally lose a portion of it by forgetting to switch off US withholding for two or three years.

The PFIC Trap: Why Non-US Funds Are Toxic

Any non-US pooled investment fund — a Spanish fondo, a UCITS ETF, most European mutual funds — is classified as a Passive Foreign Investment Company (PFIC) under US tax law. PFIC rules impose punitive taxation on distributions and gains (ordinary rates plus an interest charge), demand complex Form 8621 filings, and make annual mark-to-market or QEF elections the only paths to anything resembling normal treatment.

The practical rule for Americans in Spain: do not buy non-US funds. Hold US ETFs through a US brokerage that will still serve you as a non-US-resident address (Interactive Brokers, Schwab International, Fidelity International), or hold direct securities. Arriving in Spain with a portfolio of Spanish funds built "locally" by a well-meaning advisor is how many US expats discover PFIC the hard way — after years of compound damage.

State Taxes: The One You Cannot Treaty Away

US state taxes sit outside the federal treaty. California, New Mexico, Virginia, and South Carolina are the states most aggressive about continuing to claim residents who have moved abroad; ties like a driver's license, voter registration, a physical address, or a professional license can all keep you on the hook for state income tax even when you have been in Spain for a decade.

Before moving, it is worth formally breaking residence with your former state — registering to vote in a no-income-tax state (Florida, Texas, Nevada, Washington), changing your driver's license, closing in-state bank accounts — because state tax authorities do not accept the Spain-US treaty as a defense. The treaty is federal; state tax is a separate system.

Gift and Estate Tax: Two Regimes, No Treaty

The US and Spain do not share a gift or estate tax treaty (there was historically a limited estate-tax agreement that no longer applies). This means that on death, a US citizen resident in Spain can face US estate tax on worldwide assets and Spanish Inheritance and Gift Tax on the same assets, with only limited credit on the Spanish side for US tax paid. For high-net-worth binationals, this is the single largest reason to involve a cross-border estate planner before moving, not after.

How Noburo Helps

Noburo files the Spanish side — Modelo 100 with all treaty credits properly computed, Modelo 720 and 721, Modelo 210 for any lingering US-source items treated as non-resident — and coordinates with your US CPA so that the FTC numbers match on both returns. We flag the PFIC exposure before you make it worse, handle the Totalization certificate for autónomos, and set up Roth and 401(k) distribution timing before residency clocks over.

If you are still in the US and planning the move, the highest-value work happens in the last six months before you board the plane: state residency, account restructuring, pre-move Roth conversions, and a clean documentary trail for every foreign account that will show up on FBAR, FATCA, and Modelo 720 from day one. Everything we can do for you afterwards is easier if those pieces are right on arrival.