U.S.-abroad tax field guide
Moving to Spain: treaty and U.S. state-residency checklist
The U.S.–Spain treaty and protocol address categories of cross-border income, residence conflicts, and relief, while the saving clause preserves broad U.S. taxing rights over citizens.
Treaty status: In force
Treaty status is the beginning of the analysis, not the conclusion. Confirm residence under domestic law, identify the exact income article, read protocols and technical explanations, then test the saving clause and its exceptions.
What to examine in the treaty layer
- Classify each income stream before reading a treaty article; employment, pensions, business profits, and investment income are not interchangeable.
- Treat treaty residence and Spanish domestic tax residence as related but separate analyses.
- Do not assume a visa label controls tax residence or treaty eligibility.
The U.S. federal layer still exists
Worldwide-income filing
U.S. citizens generally file on worldwide income while abroad, subject to applicable exclusions, credits, deductions, and treaty provisions.
Foreign tax credit
A credit may relieve double taxation of qualifying foreign income taxes, but baskets, sourcing, carryovers, and limitations matter.
FEIE
The exclusion requires a foreign tax home plus the bona fide residence or physical presence test; moving abroad by itself is not enough.
Information reporting
FBAR, Form 8938, and entity, trust, gift, or pension forms are separate questions and can apply even when no U.S. income tax is due.
The state-residency layer
A U.S. treaty is federal. Your former state can apply its own domicile and statutory-residency rules. A flight, foreign visa, or federal foreign-residence claim does not automatically end state residence.
- Document intent and conduct: when you left, where you established a permanent home, and the facts showing where you intend to return.
- Inventory retained ties: homes, spouse or dependents, licenses, voting, vehicles, business interests, professional licenses, mail, and time in the state.
- Check a separate day/abode test: some states can treat a domiciliary nonresident as resident under a statutory test.
- Use filing-year instructions: part-year and nonresident filing, state-source income, and safe-harbor rules can change.
Spain pre-move questions
- 1Document days, home availability, work location, and center-of-economic-interest facts for the Spanish tax year.
- 2Map foreign accounts and assets early enough to ask about Spanish information-reporting rules.
- 3Coordinate the timing and sourcing of income before choosing between U.S. credit or exclusion strategies.
Official sources
Accessed October 1, 2026. Re-open the live source and current filing-year instructions before acting.
Official treaty text; consult the IRS treaty index for later protocols and technical explanations.
Spain Tax Agency — Individual tax residence in SpainOfficial English-language overview of Spanish individual residence criteria.
IRS — United States income tax treaties A to ZCurrent IRS index for treaty texts and related technical explanations.
IRS Publication 54 — Tax Guide for U.S. Citizens and Resident Aliens AbroadFederal filing, foreign earned income, housing, and residency overview for Americans abroad.
IRS — Foreign Tax CreditOfficial overview of the credit that may reduce double taxation of foreign-source income.
IRS — Foreign Earned Income ExclusionOfficial eligibility and filing overview; moving abroad alone does not qualify someone.
California FTB Publication 1031 — Guidelines for Determining Resident StatusOfficial California guidance on residency, domicile, temporary or transitory purpose, and safe-harbor concepts.
New York Department of Taxation — Definitions used to determine resident statusOfficial New York definitions for domicile and statutory residency.
Virginia Tax — Residency StatusOfficial Virginia explanation of domiciliary, actual, part-year, and nonresident status.
Educational only. This guide does not determine tax residence, treaty eligibility, domicile, filing status, or tax owed, and is not tax, legal, financial, or accounting advice. Use qualified advisers in the United States and Spain.