Filing your federal tax return when your spouse is not a U.S. citizen starts with one question: does the IRS treat your spouse as a resident alien or a nonresident alien? That classification decides which filing statuses are open to you, whether your spouse’s foreign income lands on your return, and whether foreign bank accounts have to be disclosed. For 2026, choosing between Married Filing Jointly and Married Filing Separately is the difference between a $32,200 standard deduction and a $16,100 one, so the stakes are real.1Internal Revenue Service. Rev. Proc. 2025-32
Is Your Spouse a Resident or Nonresident Alien?
A resident alien is taxed like a U.S. citizen: worldwide income from every source goes on Form 1040.2Internal Revenue Service. Reporting Foreign Income and Filing a Tax Return When Living Abroad A nonresident alien generally owes U.S. tax only on U.S.-source income.3Internal Revenue Service. Taxation of Nonresident Aliens
Your spouse qualifies as a resident alien by passing either of two tests set out in 26 U.S.C. § 7701(b).4Office of the Law Revision Counsel. 26 U.S. Code 7701 – Definitions
- The Green Card Test. Holding a green card at any point during the calendar year makes your spouse a resident alien for that entire year.
- The Substantial Presence Test. Your spouse must be physically present in the United States for at least 31 days in the current year, and the weighted total of days over a three-year window must reach 183. The formula counts every day in the current year at full value, one-third of each day in the prior year, and one-sixth of each day in the year before that.5Internal Revenue Service. Substantial Presence Test
Some days don’t count. Days on an F or J student visa, as a foreign government diplomat, or under a handful of other exempt categories are excluded from the calculation. A “closer connection” exception can also apply: if your spouse was present fewer than 183 days in the current year and can show a tax home in a foreign country with stronger ties than to the U.S., they can avoid resident status even if the weighted formula technically crosses 183.
If your spouse arrives or leaves mid-year and becomes resident partway through, they are a dual-status alien, with worldwide income taxable only for the resident portion of the year.6Internal Revenue Service. Taxation of Dual-Status Individuals The dual-status mechanics are usually unnecessary because the joint election below treats your spouse as a resident for the whole year, which is simpler and often better.
Your Filing Status Options
Once you know how the IRS classifies your spouse, three paths open up:
- Married Filing Jointly, available only if you elect to treat a nonresident spouse as a resident under Section 6013(g).
- Married Filing Separately, the default when you don’t make that election.
- Head of Household, available in some situations even though you’re married, with a $24,150 standard deduction for 2026 and wider brackets than MFS.1Internal Revenue Service. Rev. Proc. 2025-32
The joint election gives you the biggest standard deduction and the most generous brackets but drags your spouse’s worldwide income onto your return. The default separate status keeps foreign income out but costs you half the standard deduction and blocks or limits a long list of credits. Head of Household sits in between, if you qualify.
Making the 6013(g) Election to File Jointly
Married Filing Jointly is normally off-limits when one spouse is a nonresident alien. Section 6013(g) of the Internal Revenue Code creates an exception: the U.S. citizen or resident alien spouse can elect to treat the nonresident spouse as a resident alien, which unlocks joint filing.7Office of the Law Revision Counsel. 26 USC 6013 – Joint Returns of Income Tax by Husband and Wife
How to Make the Election
Both spouses attach a signed statement to a joint Form 1040 for the first tax year the election takes effect. The statement includes the names, addresses, and Social Security numbers or ITINs for both spouses and a clear declaration that the nonresident spouse agrees to be treated as a U.S. resident for all federal income tax purposes. Both spouses sign.
The election is generally due with the return (including extensions) for the first applicable year. A late election is possible if you can show reasonable cause and good faith. If you missed the election in the first year you qualified, you can elect in a later year and file amended returns on Form 1040-X for any earlier open tax years.8Internal Revenue Service. Instructions for Form 1040-X
What You Give Up
Once the election is in place, your spouse’s worldwide income from every country goes on the joint return.9Internal Revenue Service. Foreign Earned Income Exclusion If that income is substantial, the extra U.S. tax can wipe out the benefit of joint rates. Tools for softening the hit are below.
Your spouse also becomes a “U.S. person” for foreign account reporting. If the combined value of foreign accounts tops $10,000 at any point in the year, your spouse must file FinCEN Form 114, the FBAR.10Internal Revenue Service. Report of Foreign Bank and Financial Accounts (FBAR) Penalties run up to $10,000 per non-willful violation and up to the greater of $100,000 or 50% of the account balance for willful ones. Ordinary bank accounts in your spouse’s home country count, and this requirement surprises many couples.
The One-Election Rule
The election stays in effect every year after it is made. It terminates if either spouse revokes it, if you legally separate or divorce, or if either spouse dies. The IRS can also end it for inadequate recordkeeping or non-cooperation.
Here is the trap: once the election ends for any reason, the same two individuals can never make a 6013(g) election again. Revoking is permanent. Think carefully before pulling the plug.
If Your Spouse’s Country Has a Tax Treaty
Some U.S. income tax treaties contain tie-breaker provisions that let an individual claim nonresident status for treaty purposes even after a 6013(g) election. Using one requires attaching Form 8833, Treaty-Based Return Position Disclosure.11Internal Revenue Service. About Form 8833, Treaty-Based Return Position Disclosure Under Section 6114 or 7701(b) Skipping the form can trigger a $1,000 penalty.12Internal Revenue Service. Form 8833 – Treaty-Based Return Position Disclosure Under Section 6114 or 7701(b) Claiming nonresident status through a treaty may also disqualify your spouse from certain refundable credits, including the Additional Child Tax Credit, so weigh the treaty benefit against those lost credits before you commit.
Filing Separately or as Head of Household
If you don’t make the election, your default is Married Filing Separately. You report only your own income on Form 1040 and claim the $16,100 standard deduction.1Internal Revenue Service. Rev. Proc. 2025-32 If your nonresident spouse has U.S.-source income, they file their own Form 1040-NR. U.S. trade or business income is taxed at graduated rates; other U.S.-source income such as dividends, rents, and royalties is generally subject to a flat 30% withholding rate unless a treaty reduces it.13Internal Revenue Service. Fixed, Determinable, Annual, or Periodical (FDAP) Income
Head of Household is often a better alternative if you qualify. The IRS treats you as “unmarried” for this purpose if your spouse was a nonresident alien at any time during the year and you did not elect to treat them as a resident.14Internal Revenue Service. U.S. Citizens and Residents Abroad – Head of Household You still need a separate qualifying person (your nonresident spouse cannot be that person), typically a dependent child who lives with you for more than half the year, and you must pay more than half the cost of maintaining the household. Without a qualifying person, Married Filing Separately is your only option.
One caution for the nine community property states (Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin): when you file separately, state law may require you to split community income in half on each spouse’s return, regardless of who earned it.15Internal Revenue Service. Publication 555 (12/2024), Community Property A narrow exception in Section 66 of the Internal Revenue Code lets separated spouses who live apart for the entire year report only their own earned income if they meet all the statutory conditions.16Office of the Law Revision Counsel. 26 U.S. Code 66 – Treatment of Community Income Couples living together can rarely use it.
If Your Spouse Needs an ITIN
Your spouse needs a tax ID number to appear on your return. If they don’t have a Social Security number, they’ll apply for an Individual Taxpayer Identification Number (ITIN) on Form W-7.17Internal Revenue Service. About Form W-7, Application for IRS Individual Taxpayer Identification Number
The W-7 asks why the ITIN is needed (electing to file jointly, in this case) and requires identity documents proving both identity and foreign status. A passport is the one document that satisfies both on its own. Without one, your spouse needs at least two other documents with a photograph. Originals or copies certified by the issuing agency are required; notarized photocopies won’t be accepted.
Three ways to submit:
- By mail to the IRS ITIN Operation office in Austin, Texas, with the W-7, your tax return, and the identity documents. Slowest, and risky if you’re mailing an original passport.
- Through a Certifying Acceptance Agent, who reviews originals in person and certifies copies for the IRS so your spouse keeps the documents. Private fees vary.
- At an IRS Taxpayer Assistance Center, where an employee verifies originals in person. Appointments can be hard to get during filing season.
The W-7 must be submitted together with the tax return. On the return itself, write your spouse’s name and put “ITIN APPLIED FOR” in the SSN field. ITINs lapse if they aren’t used on a return for three consecutive years, expiring on December 31 of that third year.18Internal Revenue Service. How to Renew an ITIN A lapsed ITIN has to be renewed on the same Form W-7 before it can be used again.
Avoiding Double Tax on Foreign Income
Once your spouse is treated as a resident and reports worldwide income, foreign governments may have already taxed the same money. Two tools help.
Foreign Tax Credit
The Foreign Tax Credit offsets your U.S. tax dollar-for-dollar against income taxes your spouse paid to another country. You claim it on Form 1116.19Internal Revenue Service. Foreign Tax Credit It covers income taxes, war profits taxes, and excess profits taxes paid to a foreign government, and it applies to wages, investment income, and business profits alike. The credit can’t exceed the U.S. tax attributable to the foreign income, so a higher foreign rate leaves excess credits, which you can carry forward for up to ten years. For most couples, this is the more flexible choice.
Foreign Earned Income Exclusion
The Foreign Earned Income Exclusion lets your spouse exclude up to $132,900 of foreign wages or self-employment income from U.S. tax for 2026.20Internal Revenue Service. Figuring the Foreign Earned Income Exclusion To qualify, your spouse must have a tax home in a foreign country and either be a bona fide resident of that country for an entire tax year or be physically present abroad for at least 330 days in a 12-month period. The exclusion covers earned income only, not investment income, pensions, or government pay.
You can’t use both tools on the same income. If your spouse excludes $132,900 of foreign wages, no credit is available for foreign taxes on that excluded portion. Many couples pair the exclusion with the credit on income the exclusion doesn’t reach, but running the numbers both ways before filing is worthwhile.
How You Actually File the Return
If you’re making the 6013(g) election or applying for an ITIN with the return, you generally can’t e-file. The election statement and W-7 identity documents require manual processing. The paper package should contain:
- The completed and signed Form 1040.
- The signed Section 6013(g) election statement.
- Form W-7 with required identity documents, if applying for an ITIN.
- Form 8833, if claiming a treaty-based position.
Everything goes to the IRS ITIN Operation office in Austin, Texas, so the W-7 and the return are processed together. A missing document triggers rejection and restarts the clock.
Returns filed with a W-7 take roughly seven weeks under normal conditions and nine to eleven weeks during peak season (January 15 through April 30) or when sent from overseas.21Internal Revenue Service. Individual Taxpayer Identification Number (ITIN) Any refund waits until the ITIN is assigned and the return is fully processed, so filing before the peak window can save weeks.
Looking ahead, your spouse may need to make quarterly estimated tax payments in future years if foreign income isn’t subject to U.S. withholding. The general rule: estimated payments are required if you expect to owe at least $1,000 after withholding and refundable credits, and withholding won’t cover at least 90% of the current year’s tax or 100% of last year’s (110% if adjusted gross income exceeds $150,000).22Internal Revenue Service. Topic No. 306, Penalty for Underpayment of Estimated Tax Underpayment penalties accrue quarterly.
A Note on Estate and Gift Taxes
Income tax is only part of the picture. The unlimited marital deduction that lets citizen spouses leave each other everything estate-tax-free does not apply when the surviving spouse is not a U.S. citizen. Lifetime gifts to a non-citizen spouse are capped at $194,000 for 2026 before gift tax applies, versus unlimited for citizen spouses.1Internal Revenue Service. Rev. Proc. 2025-32 Preserving the marital deduction at death generally requires assets to pass into a Qualified Domestic Trust under 26 U.S.C. § 2056A.23Office of the Law Revision Counsel. 26 USC 2056A – Qualified Domestic Trust The 2026 federal estate tax exemption is $15,000,000 per person, so smaller estates aren’t affected, but anyone above that threshold with a non-citizen spouse should talk to an estate planning attorney well before it matters.