If you are a U.S. citizen or resident but your spouse is not, you can use the married filing jointly status on your U.S. federal income tax return if you elect to treat your spouse as a resident for tax purposes. By filing a joint return you would pay a lower tax rate than if you use the married filing separately status. Whether you should make this election depends on your income and your nonresident spouse’s income.
According to the IRS, if you elect to treat your nonresident spouse as a resident for tax purposes, you would both be subject to U.S. income tax on your worldwide income. Usually a nonresident is subject to U.S. income tax only on U.S. source income.
To determine whether it is to your advantage to treat your spouse as a resident for tax purposes, you could calculate your taxes both ways before you file your return: married filing separately including only your income, and married filing jointly including both your worldwide incomes. If your spouse has considerable income outside the U.S., it may not be to your advantage to file jointly, even though the rates are lower.
To make the choice to treat your nonresident spouse as a resident for tax purposes, you attach a statement to the joint tax return you file. The statement must be signed by both spouses and must indicate that on the last day of the tax year, one spouse is a nonresident and the other is a U.S. citizen or resident and that you choose to be treated as residents for the entire year. And you must indicate your names, addresses, and identification numbers.
When you make this choice and file a joint return, you would need to request an individual taxpayer identification number (ITIN) for your nonresident spouse, unless your spouse has a social security number. You can apply for an ITIN by filing Form W-7.
After you make the choice to treat your nonresident spouse as a resident for tax purposes and file a joint return, in later years you could file either a joint return or separate returns.
If you do not choose to file a joint return, you might qualify to file as head of household. This would generally result in a lower rate of tax than if you file as married filing separately. And you can claim a higher standard deduction.
To file as head of household you must be considered unmarried. According to the IRS, you are considered unmarried for head of household purposes if your spouse was a nonresident alien at any time during the year and you do not choose to treat your spouse as a resident for U.S. income tax purposes.
To qualify to file as head of household, you must have paid more than half the cost of keeping up a home for the year. And you must have a qualifying person living with you for more than half the year. Your spouse is not a qualifying person for head of household purposes. You would need to have another qualifying person, who could be a child or other relative.
If you do not elect to treat your spouse as a U.S. citizen or resident, and you do not qualify to file as head of household, you would have to file as married filing separately. You could not file as single if you are married.
