All US citizens and Green Card holders must pay US income tax. Whole worldwide income is considered, not just income from the United States.
Anyone living and earning in the US may be required to file a US tax return, depending on source of income and tax filing status.
Groups of non-US citizens obliged to file the tax return
- non-resident alien individual engaged or considered to be engaged in a trade or business in the United States during the year
- non-resident alien individual who is not engaged in a trade or business in the United States and has U.S. income on which the tax liability was not satisfied by the withholding of tax at the source.
- representative or agent responsible for filing the return of an individual described in previous points
- fiduciary for a nonresident alien estate or trust, or
- resident or domestic fiduciary, or other person, charged with the care of the person or property of a nonresident individual may be required to file an income tax return for that individual and pay the tax
Still not sure? See the official questionnaire to find out if you need to file a US tax return.