Who Must File an Income Tax Return If you are a nonresident alien individual visiting the United States only for pleasure, receive no income from U.S. sources, and are not engaged or considered to be engaged in a trade or business in the United States, you do not have to file a U.S. income tax return. If, in 2001, you are a nonresident alien and you work or are engaged or considered to be engaged in a trade or business in the United States, you must file a U.S. income tax return even if: Your income did not come from a trade or business conducted in the United States, You have no income from U.S. sources, or Your income is exempt from U.S. income tax. If you perform personal services in the United States at any time during the tax year, you usually are considered engaged in a trade or business in the United States. For an exception to this rule, see Employees of foreign persons, organizations, or offices, next. Employees of foreign persons, organizations, or offices. Income for personal services performed in the United States as a nonresident alien is not considered to be from U.S. sources and is tax exempt if you meet all three of the following conditions. You either: Perform personal services as an employee of or under a contract with a nonresident alien individual, foreign partnership, or foreign corporation, not engaged in a trade or business in the United States, or Work for an office or place of business maintained in a foreign country or possession of the United States by a U.S. corporation, a U.S. partnership, or a U.S. citizen or resident. You perform these services while you are a nonresident alien temporarily present in the United States for a period or periods of not more than a total of 90 days during the tax year. Your pay for these services is not more than $3,000. If you do not meet all three conditions, your income from personal services performed in the United States is U.S. source income and is taxed according to the rules found in chapter 4 of Publication 519. Others who must file. If you are not engaged in a trade or business in the United States, you must file a return if you have U.S. income on which the tax liability was not satisfied by the withholding of tax at the source. You must file a return if you are claiming a refund of overwithheld or overpaid tax. Also, you must file a return if you want to claim the benefit of any deductions or credits. For example, if you do not have a job or trade or business in the United States, but you do have rental or royalty income from an interest in U.S. real property, you may choose to treat that activity as a U.S. trade or business. To claim a deduction for any allowable expenses related to that business, you must timely file a true and accurate return. With certain exceptions, you must file a return when you take the position that a U.S. tax treaty overrules or modifies a U.S. tax law. You must provide special information with the return, including a statement of facts supporting your position. For details, see Reporting Treaty Benefits Claimed in chapter 9 of Publication 519. Identification number. You must furnish a taxpayer identification number on returns, statements, and other tax related documents. You can get a taxpayer identification number by filing Form W-7, Application for IRS Individual Taxpayer Identification Number, with the IRS.