Two systems with a claim on you
Here is the situation in plain terms. The United States taxes its citizens on their worldwide income, no matter where they live. Spain taxes its tax residents on their worldwide income too. If you live in Spain as an American, both governments have a claim on the same euros.
The US–Spain tax treaty and a set of IRS tools exist to keep you from paying full tax twice — but using them correctly means understanding how the pieces fit together. This guide walks through what makes you a Spanish tax resident, how the IRS expects you to file while abroad, the two main tools for avoiding double taxation, and the reporting obligations that trip people up. It also flags where the complexity spikes: freelancers, LLC owners, and Digital Nomad Visa holders especially.
Understanding this framework before you arrive is one of the most valuable things you can do for yourself. For the Spanish side of the picture — IRPF brackets, wealth tax, regional differences — pair this with our Legal & Taxes overview.
First: are you a Spanish tax resident?
Before worrying about double taxation, you need to know whether Spain considers you a tax resident. The main rule is straightforward.
Spend 183 days or more in Spain during a calendar year and you are a Spanish tax resident — liable for IRPF on your worldwide income, with progressive rates reaching 47% at the top bracket. The clock starts from day one, not from the date your visa is issued or the date you register.
Once you become a resident, the Agencia Tributaria(AEAT — Spain's equivalent of the IRS) treats you as liable for IRPF (Impuesto sobre la Renta de las Personas Físicas), personal income tax, on income earned anywhere in the world. Spain also has a secondary test based on economic interests: if the nucleus of your economic activity or interests sits in Spain, you can be treated as a resident even without 183 days. For most people, the day-count test is the one that matters.
The practical implication: on a Non-Lucrative Visa, a Digital Nomad Visa, or any other long-stay visa, spend more than 183 days in Spain during your first year and you become a Spanish tax resident for that year — and owe Spanish income tax on your worldwide income.
The US side: you still file
US citizens living in Spain are still required to file a US federal income tax return every year. This is not optional, and it does not depend on whether you owe any US tax — the requirement exists on citizenship alone. You are taxed on worldwide income: wages, self-employment, rental income, investment income, and more.
Key deadlines for Americans abroad
April 15 — standard deadline
The same date domestic filers face. Any US tax you owe is due now — interest accrues from here regardless of when you actually file.
June 15 — automatic extension
A two-month extension granted automatically to citizens living outside the US — no form required. It is an extension to file, not to pay.
October 15 — further extension
Available by filing Form 4868 before June 15. Again, an extension to file, not to pay.
The two primary tools for reducing or eliminating US tax while living in Spain are the Foreign Earned Income Exclusion and the Foreign Tax Credit. They are covered next.
The Foreign Earned Income Exclusion
The FEIE lets qualifying Americans abroad exclude a portion of their foreign earned income from US taxable income. For 2023, the exclusion was $120,000 per person; the figure adjusts annually for inflation — check the current year's amount at irs.gov before filing.
To claim it, you must
Most Americans in Spain on a long-stay visa for more than a year meet the Bona Fide Residence Test. The Physical Presence Test is useful before you've completed a full tax year abroad.
The self-employment trap
The FEIE reduces your US income tax on the excluded amount — but it does not reduce US self-employment tax (Social Security and Medicare). Exclude $100,000 of self-employment income and you still owe roughly 15.3% on the first $168,600 of net earnings. This catches many freelancers off guard — though the Totalization Agreement below may change the picture.
The Foreign Tax Credit
The Foreign Tax Credit lets you credit taxes paid to Spain against your US tax liability, dollar for dollar (up to certain limits). The logic: if Spain taxed income at 30% and the US would tax the same income at 30%, the credit eliminates the US tax — you've already paid it. You aren't double-taxed; you effectively pay the higher of the two rates.
FEIE vs. Foreign Tax Credit — which is better?
You cannot apply both tools to the same dollars — but you can use one for some income and the other for the rest. If you elect the FEIE, you cannot then apply the Foreign Tax Credit to the excluded income. This is one of the decisions that genuinely requires a dual-qualified professional; getting it wrong, or missing the election deadline, can cost far more than the accountant's fee.
The US–Spain tax treaty
The two countries have a tax treaty in force — the Convention for the Avoidance of Double Taxation, signed in Madrid on February 22, 1990, later updated by a Protocol that brought it closer to current tax-treaty policy. Its provisions matter most for cross-border business and investment income.
Treaties reduce or eliminate taxation at the sourcefor specific income categories — they don't replace the FEIE/FTC analysis for most Americans in Spain. The treaty is directly relevant if you receive royalties, dividends from a US company, or income from a US business entity while living in Spain. In those cases, consult a specialist.
FBAR: reporting foreign bank accounts
Separate from your income tax return, US citizens with foreign bank accounts have an annual reporting obligation under the Bank Secrecy Act. You must file an FBAR (FinCEN Form 114) if the aggregate value of all your foreign financial accounts exceeded $10,000 at any point during the year. It is a report, not a tax — but non-compliance carries serious civil and criminal penalties.
Penalties are severe. Willful violations can reach the greater of $100,000 or 50% of the account balance per violation. If you have foreign accounts and have never filed, the IRS offers a streamlined compliance procedure with reduced or waived penalties for certain taxpayers — talk to a professional before attempting it.
FATCA: Form 8938
FATCA imposes a separate — and higher-threshold — reporting requirement for foreign financial assets. Unlike the FBAR, Form 8938 is filed with your federal income tax return. For US citizens living abroad and filing single, the thresholds are:
For married couples filing jointly, these thresholds double to $400,000 and $600,000.
FATCA covers a broader range of assets than the FBAR — not just bank accounts, but foreign stocks, bonds, interests in foreign entities, and foreign-issued insurance and annuity contracts. The IRS publishes a side-by-side comparison of the two requirements worth reviewing if you hold anything beyond a basic account.
The Beckham Law and US taxes
If you hold a Digital Nomad Visa and elect Spain's special expatriate regime (the Régimen Especial de Impatriados, the Beckham Law), your Spanish position shifts significantly: instead of progressive IRPF up to 47% on worldwide income, eligible holders pay a flat 24% on Spanish-source income up to €600,000. That changes how you should use your US tools.
FEIE interaction
Under the Beckham Law, foreign-source income is taxed differently — often at lower rates or exempt in Spain. That reshapes the FEIE and Foreign Tax Credit calculus, and the optimal mix becomes genuinely case-specific.
Foreign Tax Credit interaction
If your Spanish rate under the Beckham Law is lower than your US rate, the Foreign Tax Credit may not fully offset your US liability. The FEIE can fill the gap — but, again, not on the same dollars.
Bottom line: a Beckham Law election makes your US filing noticeably more complex than under the standard Spanish regime. This is not a situation for DIY software or generic expat guides. For the Spanish-side mechanics and the six-month election window, see our Digital Nomad Visa guide.
The Single-member US LLC situation
A significant number of Americans arrive as Digital Nomad or NLV holders while continuing to operate a single-member US LLC — common among freelancers who set up a US entity before moving. The tax picture here is genuinely complex, and I want to be direct about the limits of what an article can responsibly tell you.
US treatment
A single-member LLC is a “disregarded entity” for US federal tax. Its income flows straight to your Form 1040 as self-employment income. The FEIE is potentially available on earned income from services you perform in Spain.
Spanish treatment
Spain's AEAT may look through your US LLC and treat its income as personal income subject to IRPF. Whether it's characterized as employment, professional, or business income affects which withholding and reporting rules apply.
How the FEIE applies when income flows through a US LLC to a Spain-resident citizen working in Spain can go several ways — depending on the nature of your work, your clients, your invoicing, and how AEAT characterizes the income. There are also implications for whether the Totalization Agreement applies and whether your LLC needs to register as a permanent establishment in Spain.
A bad assumption here is expensive
Get specialist advice — from someone who handles both US and Spanish tax — before you arrive, or very shortly after. See How to Become Autónomo for how self-employment status layers on top.
Social Security: the Totalization Agreement
The US and Spain have a Social Security Totalization Agreement in force, addressing situations where workers could otherwise owe Social Security taxes in both countries at once.
US employees working in Spain
For a US employer, generally covered by US Social Security for the first five years, after which Spanish rules apply.
Self-employed, registered as autónomo
If you reside in Spain and register under RETA, you're generally covered by Spanish Social Security — not US. Spanish RETA contributions replace US self-employment tax on Spanish-source income.
For most Americans registered as autónomo, this can reduce total Social Security liability versus paying both — but the analysis is fact-specific. Note the agreement applies to Social Security taxes, not income taxes; it doesn't affect the FEIE/FTC analysis.
Key filing deadlines: a cheat sheet
Miss the Beckham Law window and it's gone for that year. When April 15 or 15/20 dates fall on a weekend or holiday, deadlines shift to the next business day.
Where to find professional help
The best professionals for this situation specialize specifically in US expat taxation and have direct experience with Spain. Look for two — often coordinated together.
US expat CPA or Enrolled Agent
With an international tax specialty — FBAR, Form 8938, the Foreign Tax Credit, FEIE, and the US–Spain treaty. Not a job for a general US tax preparer.
Spanish asesor fiscal
Who can coordinate with your US CPA — handling Beckham elections, Modelo 720, and how AEAT characterizes your income.
Free-standing resources
American Citizens Abroad and the IRS Taxpayer Advocate Service can help you navigate the system when you're stuck.
Ask before you engage
Ask every professional specifically about their experience with US expats and LLC owners. The interaction of two tax systems is exactly where general practitioners get it wrong.
Sources
Frequently asked questions
Do I have to file a US tax return if I don't owe any US tax?
Can I use tax software like TurboTax to file as an expat in Spain?
I arrived mid-year. Am I a Spanish tax resident for my first year?
Does US tax apply to income I earn from Spanish clients?
What happens if I have both a US LLC and autónomo status in Spain?
Are IRA and 401(k) contributions affected by living in Spain?
This is not legal or tax advice. US and Spanish tax law are both complex, change frequently, and interact in ways that vary significantly by individual situation. Consult a qualified Spanish lawyer or accountant — and a US expat CPA — for your specific situation before making any filing decisions. If you have a US business entity such as an LLC, that consultation is particularly important.