The Effect of Tax Treaties
The rules given to determine if you are a U.S. resident do not override tax treaty definitions of residency.
If your residency is determined under a treaty and not under the rules discussed here, you must file a fully completed Form 8833, Treaty-Based Return Position Disclosure Under Section 6114 or 7701(b) (PDF) if the payments or income items reportable because of that determination are more than $100,000.
If you are a dual resident taxpayer, you can still claim the benefits under an income tax treaty. A dual resident taxpayer is one who is a resident of both the United States and another country under each country's tax laws. The income tax treaty between the two countries must contain a provision that provides for resolution of conflicting claims of residence.
If you are treated as a resident of a foreign country under a tax treaty, you are treated as a nonresident alien in figuring your U.S. income tax. For purposes other than figuring your tax, you will be treated as a U.S. resident. For example, the rules discussed here do not affect your residency time periods.
If you are a dual resident taxpayer and you claim treaty benefits, you must timely file a return (including extensions) using Form 1040NR, U.S. Nonresident Alien Income Tax Return (PDF) or Form 1040NR-EZ, U.S. Income Tax Return for Certain Nonresident Aliens With No Dependents (PDF), and compute your tax as a nonresident alien. You must also attach a fully completed Form 8833, Treaty-Based Return Position Disclosure Under Section 6114 or 7701(b) (PDF).
Treasury Regulation 301.6114-1
Note: This page contains one or more references to the Internal Revenue Code (IRC), Treasury Regulations, court cases, or other official tax guidance. References to these legal authorities are included for the convenience of those who would like to read the technical reference material. To access the applicable IRC sections, Treasury Regulations, or other official tax guidance, visit the Tax Code, Regulations, and Official Guidance page. To access any Tax Court case opinions issued after September 24, 1995, visit the Opinions Search page of the United States Tax Court.