This publication is for visitors to the United States. If you have income from sources inside the United States, you may have to file a U.S. income tax return even if you are only visiting this country. For purposes of this publication, a "visitor to the United States" is a "nonresident alien." This publication summarizes the requirements of U.S. income tax law relating to nonresident aliens and is for nonresident aliens only.

You are a nonresident alien unless you are either a U.S. citizen or a resident alien of the United States. You are a resident alien of the United States if you meet either the substantial presence test or the green card test. Even if you do not meet either of these tests, you may be able to choose to be treated as a U.S. resident alien for part of the year. See First-Year Choice under Dual-Status Aliens in Publication 519, U.S. Tax Guide for Aliens.

You meet the substantial presence test if you are physically present in the United States for at least:

1. 31 days during 2010, and
2. 183 days during the period 2010, 2009, and 2008, using the following chart.

(a)	(b)	(c)	(d)
Year	Days of physical presence	Multiplier	Testing days (multiply (b) times (c))
2010		1.000
2009		.333
2008		.167
Total testing days (add column (d))

For more information about the substantial presence test, see Publication 519.

You meet the green card test if you are a lawful permanent resident of the United States. You generally have this status if you have been issued an alien registration card, also known as a "green card." You continue to be a resident under this test unless the status is taken away from you or is determined to have been abandoned. For more information about the green card test, see Publication 519.

You can be both a nonresident alien and a resident of the United States during the same tax year. This usually occurs in the year you arrive in or depart from the United States. Aliens who have dual status should see chapter 6 of Publication 519 for information on filing a return for a dual-status tax year.

We welcome your comments about this publication and your suggestions for future editions.

You can write to us at the following address:

 
Internal Revenue Service 
Individual Forms and Publications Branch 
SE:W:CAR:MP:T:I 
1111 Constitution Ave. NW, IR-6526 
Washington, DC 20224

We respond to many letters by telephone. Therefore, it would be helpful if you would include your daytime phone number, including the area code, in your correspondence.

You can email us at *taxforms@irs.gov. (The asterisk must be included in the address.) Please put "Publications Comment" on the subject line. You also can send us comments from www.irs.gov/formspubs/index. Select "Comment on Tax Forms and Publications" under "Information about." Although we cannot respond individually to each comment received, we do appreciate your feedback and will consider your comments as we revise our tax products.

Visit www.irs.gov/formspubs to download forms and publications, call 1-800-829-3676, or write to the address below and receive a response within 10 business days after your request is received.

 
Internal Revenue Service  
1201 N. Mitsubishi Motorway 
Bloomington, IL 61705-6613

If you have a tax question, check the information available on IRS.gov or call 1-800-829-1040. We cannot answer tax questions sent to either of the above addresses.

If you are a nonresident alien 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.

Table 1, shown later, can help you determine whether you have U.S. source income. Also, see What Income Is Taxed, later.

You must file a U.S. income tax return if you engaged or were considered to be engaged in a trade or business in the United States during 2010.

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.

Whether you are engaged in a trade or business in the United States depends on the nature of your activities. If you perform personal services (work) 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.

If you are in doubt whether or not you are engaged in a trade or business, see Trade or Business in the United States in chapter 4 of Publication 519.

Even 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 and not enough income tax was withheld to pay the tax that is due.

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, trade, or business in the United States, but you do have rental property 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.

You must furnish a taxpayer identification number on returns, statements, and other tax-related documents.

Generally, your identification number is a social security number (SSN).

If you do not have an SSN but are eligible to get one, you should apply for it. Get Form SS-5, Application for a Social Security Card, online at www.socialsecurity.gov, from your local Social Security Administration (SSA) office, or by calling the SSA at 1-800-772-1213.

If you do not have and are not eligible to get an SSN, you must enter your individual taxpayer identification number (ITIN) where an SSN is requested on your tax return.

For details on how to apply for an ITIN, see Form W-7, Application for IRS Individual Taxpayer Identification Number, and its instructions. Get Form W-7 online at IRS.gov. Click on "Individuals," then "Individual Taxpayer Identification Numbers."

An employer identification number (EIN) is required if you are engaged in a trade or business as a sole proprietor and have employees or a qualified retirement plan. To apply for an EIN, file Form SS-4, Application for Employer Identification Number, with the IRS. Information is available at IRS.gov. In the search box enter "Employer ID Numbers (EINs)." For more information, see Publication 519.