If you're moving from Spain to the United States and wondering how it will affect your taxes, you're not alone. Thousands of expats make this transition every year, and the tax implications can be significant — and surprisingly complex. Proper expat tax planning between Spain and the United States requires understanding both countries' tax systems, knowing when your obligations start and stop, and leveraging the US-Spain tax treaty to avoid being taxed twice on the same income.

This comprehensive guide walks you through everything you need to know about relocation tax planning for your move in the 2025/2026 tax year, including residency rules, filing requirements, key deadlines, and practical strategies to keep more of your hard-earned money.

Understanding Tax Residency: When Do Your Obligations Shift?

The single most important concept in international relocation tax planning is tax residency. Both Spain and the United States have their own rules for determining whether you're a tax resident, and it's entirely possible — and common — to be considered a tax resident of both countries during your year of transition.

Spanish Tax Residency Rules

Under Spanish law (Ley del IRPF), you are considered a tax resident of Spain if any of the following apply:

  • You spend more than 183 days in Spain during a calendar year (January 1 to December 31)
  • Your center of vital interests (primary economic activities or professional base) is in Spain
  • Your spouse and/or minor children reside habitually in Spain (unless you can prove otherwise)

If you leave Spain partway through 2025, you may still be treated as a Spanish tax resident for the entire year if you've already spent more than 183 days there before departing. Spanish tax residents are taxed on their worldwide income.

US Tax Residency Rules

The United States determines tax residency primarily through two tests:

  1. Green Card Test: If you hold a US permanent resident card (green card) at any point during the year, you are a US tax resident for that entire year.
  2. Substantial Presence Test: You are a US tax resident if you are physically present in the US for at least 31 days during the current year AND a total of 183 days over a three-year period using a weighted formula (all days in the current year + 1/3 of days in the prior year + 1/6 of days two years prior).

US tax residents — and, critically, US citizens and green card holders regardless of where they live — are subject to tax on their worldwide income.

The Overlap Problem

If you leave Spain in, say, June 2025 and establish residence in the US, you could potentially be a tax resident of both countries for the 2025 tax year. This is where the US-Spain Double Taxation Treaty becomes essential.

The US-Spain Double Taxation Treaty: Your Safety Net

The United States and Spain have maintained a Convention for the Avoidance of Double Taxation (signed in 1990 and updated through protocols). This treaty is your primary tool for preventing the same income from being taxed by both countries.

Key Treaty Provisions for Relocating Expats

  • Tie-Breaker Rules (Article 4): When you qualify as a tax resident of both countries, the treaty provides a hierarchy of tests to determine your residence for treaty purposes: permanent home → center of vital interests → habitual abode → nationality → mutual agreement between tax authorities.
  • Employment Income (Article 15): Generally, employment income is taxable in the country where the work is physically performed. If you work in the US after relocating, that income is typically taxable only in the US.
  • Pensions (Article 20): Private pensions are generally taxable only in the country of residence. Government pensions may follow different rules.
  • Capital Gains (Article 14): Gains from the sale of property are generally taxable in the country where the property is located. Gains from financial assets are typically taxable in the country of residence.
  • Foreign Tax Credits: Both countries allow credits for taxes paid to the other, preventing true double taxation.

Practical Example: Split-Year Scenario

Consider Maria, who leaves Barcelona for New York on July 1, 2025. She earns €40,000 from her Spanish employer (January–June) and $55,000 from her new US employer (July–December).

  • Spain: Since Maria spent 181 days in Spain (less than 183), she may argue she is not a Spanish tax resident for 2025 — though Spain could still claim residency based on her center of vital interests if her family remains in Spain. If she is treated as a non-resident for part of the year, only her Spanish-source income is taxed in Spain.
  • United States: If Maria meets the substantial presence test for 2025, she will be taxed on her worldwide income from her US residency start date (or for the full year if she elects the "first-year choice" under IRC §7701(b)).
  • Treaty relief: Any overlap is resolved by the treaty tie-breaker rules and foreign tax credits.

Use our Spain Income Tax Calculator to estimate your Spanish tax liability and our United States Income Tax Calculator to project your US federal obligations.

Spanish Tax Obligations When You Leave

Leaving Spain doesn't mean your Spanish tax obligations disappear overnight. Here's what you need to handle before and after departure.

Filing Your Final Spanish Tax Return

If you are a Spanish tax resident for 2025 (even for part of the year under the worldwide income regime), you must file a Declaración de la Renta by the standard deadline — typically late June 2026 for the 2025 tax year.

Spanish income tax (IRPF) for residents in 2025 uses progressive rates:

Taxable Income (EUR) Marginal Rate (State + Regional*)
Up to €12,450 19%
€12,451 – €20,200 24%
€20,201 – €35,200 30%
€35,201 – €60,000 37%
€60,001 – €300,000 45%
Over €300,000 47%

*Regional rates vary by autonomous community. These are approximate combined rates for 2025.

Spain's Exit Tax (Impuesto de Salida)

Since 2015, Spain has had an exit tax that applies to individuals who have been Spanish tax residents for at least 10 of the last 15 years and who own:

  • Shares or participations in any entity with a total market value exceeding €4 million, OR
  • A stake of at least 25% in an entity with shares valued above €1 million

The exit tax treats these assets as if they were sold at market value on the date you cease Spanish residency, generating a deemed capital gain taxed at Spain's savings tax rates (19%–28% in 2025). However, if you're moving to the US (a non-EU/EEA country), you generally must pay this tax upfront — unlike moves within the EU, where deferral is possible.

Common mistake: Many expats are unaware of the exit tax and fail to plan for it. If you hold significant equity positions, consult a tax advisor well before your departure date.

Notifying the Tax Authorities

You should file Modelo 030 with the Agencia Tributaria to notify them of your change of tax residency. This is an administrative step, but it's important to ensure Spain stops treating you as a resident in subsequent years.

Ongoing Spanish Tax Obligations

Even after you leave, you may still owe Spanish taxes on:

  • Rental income from Spanish property
  • Capital gains from selling Spanish real estate
  • Pensions sourced from Spain (subject to treaty rules)
  • Income from a Spanish permanent establishment

Non-resident income tax (IRNR) rates apply to these items, typically at a flat 24% for non-EU/EEA residents (which includes US residents).

US Tax Obligations: What to Expect After Arrival

The US tax system is famously comprehensive and applies to worldwide income once you become a tax resident. Here's what to anticipate.

Federal Income Tax Rates for 2025

The US uses a progressive federal income tax system. For the 2025 tax year (filing in 2026), the brackets for a single filer are approximately:

Taxable Income (USD) Marginal Rate
Up to $11,925 10%
$11,926 – $48,475 12%
$48,476 – $103,350 22%
$103,351 – $197,300 24%
$197,301 – $250,525 32%
$250,526 – $626,350 35%
Over $626,350 37%

These are federal rates only. Most US states also impose their own income tax (notable exceptions include Florida, Texas, and Nevada, which have no state income tax).

Key US Filing Requirements

  • Filing deadline: April 15, 2026 for the 2025 tax year (with extensions available to October 15)
  • Standard deduction (2025): Approximately $15,000 for single filers
  • Social Security and Medicare taxes: 7.65% for employees (matched by employers), or 15.3% for self-employed individuals
  • Foreign Bank Account Report (FBAR): If your aggregate balance in foreign (Spanish) bank accounts exceeds $10,000 at any point during the year, you must file FinCEN Form 114 by April 15 (with automatic extension to October 15)
  • FATCA (Form 8938): If your foreign financial assets exceed $50,000 on the last day of the tax year (or $75,000 at any point), you must report them on your tax return

The Foreign Tax Credit (Form 1116)

The Foreign Tax Credit is typically the most valuable tool for expats who have paid taxes to Spain on the same income the US wants to tax. You can claim a dollar-for-dollar credit against your US tax liability for income taxes paid to Spain, subject to certain limitations.

Practical example: If you earned €30,000 in Spain during the first half of 2025 and paid €5,500 in Spanish income tax, you can claim approximately $5,900 (at current exchange rates) as a foreign tax credit on your US return, reducing your US tax on that same income.

The Foreign Earned Income Exclusion (FEIE) — Does It Apply?

The Foreign Earned Income Exclusion (FEIE) under IRC §911 allows qualifying US taxpayers to exclude up to $130,000 (2025 estimate) of foreign earned income from US taxation. However, this applies mainly to US citizens or green card holders living abroad. If you're moving to the US and will be living and working there, the FEIE generally does not apply to your US-source income. It may apply to income earned in Spain before your move if you were a US tax person at that time.

Step-by-Step Relocation Tax Planning Checklist

To ensure a smooth tax transition from Spain to the United States, follow these steps:

  1. Determine your departure date carefully: Leaving Spain before day 183 of the calendar year (around July 2) can help you argue for non-resident status for the full year.
  2. Assess exit tax exposure: Review your equity holdings and determine if Spain's exit tax applies. If so, plan liquidity accordingly.
  3. File Modelo 030: Notify the Agencia Tributaria of your change of address and tax residency.
  4. Gather all Spanish income documentation: Collect payslips, tax withholding certificates (certificados de retención), and records of Spanish assets.
  5. Establish US tax residency: Keep records of your arrival date, lease agreement, Social Security number (or ITIN application), and employment start date.
  6. Choose your first-year residency election: If you arrive mid-year and meet the substantial presence test, you may elect to be treated as a US resident from your arrival date rather than the full year.
  7. Inventory all foreign financial accounts: Prepare for FBAR and FATCA reporting by listing all Spanish bank accounts, investment accounts, and pensions.
  8. Engage a cross-border tax advisor: A professional experienced in both US and Spanish tax law can save you thousands in avoided penalties and optimized credits.
  9. File all returns on time: Submit your final Spanish tax return and your first US tax return by their respective deadlines.
  10. Consider state tax implications: Research the tax rules for your specific US state of residence — this can significantly affect your total tax burden.

Common Mistakes and Misconceptions

Expats relocating from Spain to the United States frequently fall into these traps:

  • "I left Spain, so I don't owe Spanish taxes anymore." Wrong. You may still owe taxes on Spanish-source income, and your final year of residency requires a full return.
  • "The tax treaty eliminates all double taxation automatically." The treaty provides mechanisms (like foreign tax credits and tie-breaker rules), but you must actively claim these benefits on your returns. They are not applied automatically.
  • "I don't need to report my Spanish bank accounts to the US." The FBAR and FATCA requirements are separate from your income tax return and carry severe penalties for non-compliance — up to $100,000 or 50% of account balances for willful violations.
  • "I can use the Foreign Earned Income Exclusion for my US salary." The FEIE excludes foreign earned income. Once you live and work in the US, your US salary is domestic income and does not qualify.
  • "Spanish pensions aren't taxable in the US." Under the treaty, most private pensions are taxable in your country of residence — which, after your move, is the United States.
  • "I can just figure it out myself." International tax compliance involves the intersection of two countries' laws, a bilateral treaty, currency conversion rules, and overlapping deadlines. The cost of professional advice is almost always less than the cost of errors.

Frequently Asked Questions

Will I be taxed twice on my income during the year I move?

Not if you plan correctly. The US-Spain tax treaty and the Foreign Tax Credit mechanism are designed to prevent double taxation. You will need to file returns in both countries, but taxes paid to one country generally offset your liability in the other.

When should I file my last Spanish tax return?

Your final Spanish tax return (Declaración de la Renta) for the 2025 tax year is due during the standard filing period, typically April to June 2026. This applies even if you left Spain in early 2025.

Do I need to report my Spanish property on my US tax return?

Owning foreign real estate itself does not create a reporting obligation (beyond FATCA if held through a financial account). However, any rental income from Spanish property must be reported on your US return, and you must report the sale of Spanish property as a capital gain. Use the Foreign Tax Credit to offset any Spanish taxes paid on that income.

What happens to my Spanish social security contributions?

The US and Spain have a Totalization Agreement that prevents double social security taxation and allows you to combine work credits from both countries when qualifying for retirement benefits. If you've contributed to Spain's Social Security system, those credits may count toward US Social Security eligibility.

How do exchange rates affect my tax filings?

The IRS requires you to convert all foreign income, deductions, and credits to US dollars. You should generally use the yearly average exchange rate published by the IRS for income received throughout the year, or the spot rate on the date of specific transactions. Keep detailed records of the rates used.

Conclusion: Plan Early, Save More

Relocating from Spain to the United States is an exciting life change, but the tax implications demand careful attention. The intersection of Spanish and American tax law creates both challenges and opportunities — from timing your departure to maximize residency benefits, to leveraging the US-Spain tax treaty and Foreign Tax Credits to minimize double taxation.

Here are your key takeaways:

  • Timing matters: Your departure date from Spain can determine whether you're treated as a resident or non-resident for the full tax year.
  • Both countries will want to hear from you: Expect to file tax returns in Spain and the United States during your transition year.
  • The tax treaty is powerful but not automatic: You must actively claim treaty benefits and foreign tax credits on your returns.
  • Reporting obligations go beyond income: FBAR, FATCA, and the Spanish exit tax are areas where expats frequently make costly mistakes.
  • Professional advice pays for itself: A qualified cross-border tax advisor can help you navigate these complexities and potentially save you thousands.

Start by estimating your obligations using our Spain Income Tax Calculator and United States Income Tax Calculator, and consult a tax professional who specializes in US-Spain expatriate tax matters.

This article is for informational purposes only and does not constitute tax advice. Tax laws change frequently; consult a qualified tax professional for advice specific to your situation.