Filing a US tax return from abroad: who must file, and by when

Yes, you still file: Uncle Sam taxes his citizens on worldwide income wherever they live, but you get extra time and a couple of tools that can shrink the bill or wipe it out.

The short version

• US citizens and green card holders abroad file Form 1040 under the same income thresholds as people in the US. For tax year 2025, a single filer under 65 must file with gross income of at least $15,750 [3].
• Living abroad on April 15 gives you an automatic extension to June 15 to file and pay, with no form needed. Interest still runs from April 15 on unpaid tax [1][2].
• Need longer? File Form 4868 before June 15 to push the filing deadline to October 15 [1].
• Excluded foreign income still counts toward the filing threshold. Most expats who owe nothing still have to file to claim the exclusion or credit [3][5].
• The FBAR (FinCEN Form 114) is a separate report with its own deadline [6].

Who has to file

This one catches people off guard, even folks who left the States decades ago: US citizens and resident aliens are taxed on their worldwide income, and the IRS says the rules for filing income, estate and gift tax returns are "generally the same" whether you live in the US or abroad [1]. Green card holders are in the same boat until their permanent residence is formally given up.

Whether you must file comes down to gross income, filing status and age, same as back home. Gross income here means worldwide income before any exclusion. Publication 501 is explicit that income you can exclude under the foreign earned income exclusion still counts when you test whether you must file [3].

Filing thresholds for tax year 2025

These are the gross income levels that trigger a 2025 return, filed in 2026 [3]. The One Big Beautiful Bill Act raised the 2025 standard deduction mid-year, and the thresholds track it [4].

Two rows matter a lot more abroad than they do stateside. First, married filing separately: many Americans abroad are married to a non-American and file separately. At $5 of gross income, that's basically everyone. Second, self-employment: if you freelance or run a business abroad, $400 of net earnings triggers a return and possibly self-employment tax, even if the exclusion wipes out the income tax [3].

For tax year 2026, the IRS has set the standard deduction at $16,100 for single filers and married filing separately, $32,200 for joint filers and $24,150 for heads of household [4]. The 2026 filing thresholds will follow those figures for most filers under 65. Check Publication 501 for 2026 when it comes out.

The deadlines when you live abroad

Living abroad changes the April 15 drill you remember from back home. Here's the calendar for a tax year 2026 return, filed in 2027. When a date falls on a weekend or legal holiday, it moves to the next business day [1].

The June 15 automatic extension

You qualify if, on the regular due date, you are a US citizen or resident living outside the US and Puerto Rico with your main place of business or post of duty outside them, or you are in military service on duty outside the US [1][2]. You don't file a form. You attach a statement to your return explaining that you qualify.

Here's the fine print: it doesn't stop interest. The IRS is clear that you will pay interest on any tax not paid by April 15, even with the extension [1]. If you expect to owe, pay an estimate by April 15 through IRS Direct Pay or a debit or credit card, and settle the rest when you file.

The October 15 extension

If June 15 still feels tight (and for plenty of expats juggling two tax systems, it does), file Form 4868 before June 15. For people abroad, this adds up to 4 more months, to October 15 [1][2]. Form 4868 extends the time to file, not the time to pay [2]. You can file it online through IRS Free File or tax software.

Form 2350: waiting to qualify

Form 2350 is a different animal. Use it if you've just moved abroad and need more time to meet the bona fide residence test or the physical presence test for the foreign earned income exclusion [2]. It must be filed by the due date of the return [2]. It's common in your first year overseas, when you might not reach 330 days abroad until well into the following year.

What changes on the return

The return is still the same Form 1040 you filed stateside. What changes is the stack of schedules and forms you attach. Most Americans abroad use one or both of two tools to avoid paying tax twice on the same income.

1. Form 2555, the foreign earned income exclusion. It excludes foreign earned income up to $130,000 for tax year 2025 and $132,900 for tax year 2026, plus a housing amount for some people [5]. It covers wages and self-employment income only, not pensions, rent, interest or dividends.
2. Form 1116, the foreign tax credit. It credits income tax you paid abroad against the US tax on the same income. It covers both earned and unearned income.
3. Schedule SE. It covers self-employment tax for freelancers, unless a totalization agreement certificate exempts you.
4. Form 8938. It reports foreign financial assets above much higher thresholds for people living abroad.
5. Form 8833. It discloses a treaty-based return position when you rely on a tax treaty to change your US tax.

Choosing between the exclusion and the credit is the big call on most expat returns. We cover it in its own guide (see Keep reading). The short answer is that the credit often wins in high-tax countries, and the exclusion often wins in low-tax ones.

Both tools need a filed return. The IRS says expat benefits such as the exclusion and the credit can only be claimed by filing [1]. That's why "I didn't earn enough to owe anything" doesn't get you off the hook.

Practical details that differ from filing in the US

• Report in dollars. Convert foreign income to US dollars. Use a consistent, documented exchange rate. Many filers use the IRS yearly average rates for regular income.
• An SSN or ITIN for everyone on the return. A non-American spouse or child needs an ITIN to be claimed. The IRS requires an SSN or ITIN for each person on the return [1].
• E-filing works from abroad. Most of the TurboTax-style software you know accepts a foreign address. Some states and some forms still force a paper return, which goes to the IRS address listed in the Form 1040 instructions for filers with a foreign address.
• Your foreign tax year may not match. Australia, New Zealand and the UK use non-calendar tax years. Your US return still runs January to December, so you may need to split foreign payslips or assessments across two US years.
• State returns. Some states keep treating you as a resident after you move abroad. That's a separate question with its own guide.

The FBAR rides alongside

The FBAR (FinCEN Form 114) isn't part of your tax return, and it's a different agency entirely. You file it online with FinCEN through the BSA E-Filing System if your foreign accounts together exceeded $10,000 at any point in the year [6]. It's due April 15 and automatically extended to October 15, with no request needed [6]. You can owe zero tax and still have an FBAR to file. Missing it carries far heavier penalties than most people expect, so don't let it slide.

If you're behind

If this is all news to you, you're in good company: many Americans abroad learn about it years after they left. If you never filed, or skipped some years, the IRS has a program for non-willful filers living abroad: the Streamlined Foreign Offshore Procedures. They generally mean three years of returns and six years of FBARs. We cover them in a separate guide. A US expat tax preparer can check your situation before you file anything.

A step-by-step for a first expat return

1. List every source of income for the calendar year: salary, freelance fees, rent, interest, dividends and pensions, in the US and abroad.
2. Count your days abroad and note when your foreign residence started. This decides whether you qualify for Form 2555 now or need Form 2350.
3. Gather your foreign tax assessments and payslips so you can claim the foreign tax credit.
4. Find the highest balance of each foreign account during the year. You'll need it for the FBAR and maybe Form 8938.
5. By April 15, pay a ballpark estimate of any tax due.
6. By June 15, file the return with your "living abroad" statement, or file Form 4868 to move to October 15.
7. File the FBAR online by April 15, or use the automatic extension to October 15.
8. Keep copies of everything for at least the IRS and FinCEN record-keeping periods. For FBAR records, that's five years from the due date [6].

Sources

1. IRS: US citizens and resident aliens abroad
2. IRS: Publication 54 (12/2025), Tax Guide for US Citizens and Resident Aliens Abroad
3. IRS: Publication 501 (2025), Dependents, Standard Deduction, and Filing Information
4. IRS: Tax inflation adjustments for tax year 2026, including amendments from the One Big Beautiful Bill
5. IRS: Figuring the foreign earned income exclusion
6. IRS: Report of Foreign Bank and Financial Accounts (FBAR)

Keep reading

• Foreign earned income exclusion vs foreign tax credit
• FBAR: reporting your foreign bank accounts
• Catching up on missed US tax returns: the Streamlined procedures
• Rental income from a US property: taxes for Americans abroad