Which form must non-U.S. citizens who do not hold a green card use for tax purposes?

Non-U.S. citizens who do not hold a green card are classified as non-resident aliens for tax purposes. To report their income effectively, they need to use Form 1040-NR. This form is specifically designed for non-resident aliens to report their income earned from U.S. sources and calculate their tax liability accordingly.

In contrast, Form 1040 is exclusively for U.S. citizens and resident aliens. Form 1040-X is used for amending previously filed returns, and Form 1040-SR is tailored for senior citizens who are U.S. citizens or resident aliens. Therefore, using Form 1040-NR is essential for non-resident aliens as it allows them to comply with U.S. tax regulations while accurately reflecting their resident status and the specific income they are reporting.