Before completing the form W-4, you need to determine your residency status for tax purposes (see discussion, charts and exercises below). If you are a resident for tax purposes, you may complete the W-2 in the same manner as U.S. citizens. However, if you are a nonresident for tax purposes, you must complete the form using the following specific rules:

• You must check the "single" box on the W-4, even if you are married,
• You may claim only one withholding allowance, even though you may have dependents, unless you are from Canada, Mexico, or the Republic of Korea; and
• write "Nonresident Alien" or "NRA" above the dotted line on line 6.

The W-4 does not need to be updated each year, but you should update it if your tax residency status changes.