Tax
Tax Treaty
Also known as: Double Tax Treaty, DTT, Income Tax Treaty, Bilateral Tax Treaty
Tax treaties (formally Income Tax Treaties or Double Tax Conventions) are the bilateral framework for resolving cross-border tax conflicts. Each treaty has its own text but most follow the OECD Model Tax Convention (developed countries) or the UN Model Tax Convention (with developing countries) as their base structure. Key articles in a typical treaty:
• Article 4 (Residency) — defines who is a resident of each country, and provides tie-breaker rules for dual residents (permanent home → centre of vital interests → habitual abode → nationality → competent-authority decision).
• Articles 6-22 (Allocation rules) — assign primary or exclusive taxing rights for specific income types: business profits (Art. 7), shipping/aviation (Art. 8), associated enterprises and transfer pricing (Art. 9), dividends (Art. 10, often with reduced withholding rates of 5-15%), interest (Art. 11), royalties (Art. 12), capital gains (Art. 13), employment income (Art. 15, the 183-day rule for short-term assignees), directors' fees (Art. 16), pensions (Art. 18), government service (Art. 19).
• Article 23 (Elimination of Double Taxation) — defines whether the residence country uses the Exemption Method (foreign income excluded from residence-country tax) or the Credit Method (foreign tax credited against residence-country tax), or a combination.
• Article 25 (Mutual Agreement Procedure) — competent-authority dispute resolution between the two tax administrations when treaty interpretation differs.
• Article 26 (Exchange of Information) — modern treaty article enabling automatic and on-request exchange of taxpayer data, the legal scaffold underneath FATCA IGAs and CRS.
For expats, treaty positions are commonly used to: (a) reduce dividend withholding from a US-source dividend paid to a non-resident from 30% to 15% under most treaties, (b) treat a pension as taxable only in the residence country (US-Canada treaty, US-UK treaty), (c) claim the Closer Connection Exception equivalent under treaty residency tie-breakers, and (d) avoid double taxation when both countries claim taxing rights.
Notable treaty issues: the US-Italy treaty's pension provisions favor Italian residents over US residents; the US-Switzerland treaty's residency tie-breaker has been reinterpreted multiple times by competent authorities; the new US-Croatia treaty (signed 2022, ratified 2025) was the first US treaty in over a decade.
Sources
Last factual review: 2026-05-08.
Related terms
Double Taxation
Double taxation occurs when the same income or capital is taxed twice — typically once by the source country (where the income arises) and once by the residence country (where the recipient is tax resident). It's prevented by tax treaties (which allocate taxing rights) and by domestic relief mechanisms like the foreign tax credit and the foreign earned income exclusion. Unrelieved double taxation is rare in modern tax systems but can still occur with non-treaty-partner countries.
Foreign Tax Credit (FTC)
The Foreign Tax Credit lets US citizens and resident aliens reduce their US tax liability dollar-for-dollar by income taxes already paid to foreign governments on the same income. Claimed on IRS Form 1116, it prevents double taxation on income above the FEIE ceiling and on passive income that FEIE doesn't cover. The credit is per-category, capped at the US tax otherwise due on the foreign-source income, with 10-year carryforward and 1-year carryback for unused credits.
Tax Residency
Tax residency determines which country has primary right to tax your worldwide income. Each country sets its own tests — typically based on physical presence (often 183+ days/year), domicile, primary economic interests, or family ties. Holding a residence permit does not automatically establish tax residency, and tax residency does not require a residence permit. Dual tax residency is resolved by tax-treaty tie-breaker rules.
FEIE (Foreign Earned Income Exclusion)
FEIE lets US citizens and resident aliens exclude up to $132,900 (2026) of foreign-earned income from US federal income tax — but not from Social Security/self-employment tax. To qualify, the taxpayer must meet either the Bona Fide Residence Test (full-year tax residence in a foreign country) or the Physical Presence Test (330 full days abroad in any 12-month period). Claimed on IRS Form 2555 attached to Form 1040.