Filing obligations and deadlines

Generally yes — the US taxes citizens and most green card holders on worldwide income no matter where they live, so living abroad doesn't end the filing requirement if your gross income meets the threshold for your filing status. Many expats owe little or no actual tax after claiming the Foreign Earned Income Exclusion or Foreign Tax Credit, but those benefits are claimed on the return itself, which is why the filing obligation remains even when the tax bill shrinks. TFX's citizenship-based taxation guide explains why this applies abroad.

For the 2025 tax year, you generally must file if your gross income meets or exceeds $15,750 as a single filer, $31,500 for married filing jointly (both spouses under 65), or $23,625 as head of household — while married filing separately has a threshold of just $5. Separately, net self-employment earnings of $400 or more trigger a filing requirement regardless of these amounts, since self-employment tax is calculated apart from income tax. TFX's US expat tax filing guide lists these thresholds by filing status.

Unearned income is money that doesn't come from working — interest, dividends, capital gains, rent and royalties, pensions and annuities, unemployment compensation, and gambling winnings — and it generally still counts toward your adjusted gross income and taxable income even though it isn't subject to payroll taxes. For expats the distinction matters because the Foreign Earned Income Exclusion only covers earned income from services performed abroad, so unearned income can't be excluded that way and is usually handled with the Foreign Tax Credit instead. TFX's guide to unearned vs. earned income covers each category in more detail.

Yes — if you're a US citizen or green card holder, having only foreign income doesn't remove the filing requirement, because the US taxes worldwide income and doesn't distinguish between income earned at home and income earned abroad. What changes is how you reduce the tax: foreign-source wages can often be sheltered with the Foreign Earned Income Exclusion, and foreign taxes you've already paid can generate a Foreign Tax Credit, which is why many foreign-income-only filers end up owing $0 but still need to file to claim those benefits. 

Yes — the threshold is measured against your worldwide gross income, and that includes income you plan to exclude later: income removed with the Foreign Earned Income Exclusion still counts toward whether you've met the filing threshold. Gross income for this purpose spans wages, self-employment income, dividends, interest, capital gains, rental income, and retirement distributions wherever they're paid, and unearned income like dividends and capital gains counts too since the exclusion doesn't cover investment income. 

Yes, and often you should — the Foreign Earned Income Exclusion and Foreign Tax Credit are only available when you file, so without a return you lose the very tools that could bring your US tax down to zero. Filing also starts the clock on the statute of limitations: once a valid return is filed, the IRS generally has three years to assess additional tax, whereas if no return is filed that period generally doesn't begin and assessments can stay open indefinitely. TFX's guide to not filing while abroad covers why filing matters even at $0 owed.

Yes — any refund of tax you overpaid or had withheld comes back only through a filed return, even if your income was below the filing threshold and you weren't required to file. There's a deadline too: refunds for years whose original due date passed more than three years ago are generally forfeited permanently, and refundable credits such as the Additional Child Tax Credit (up to $1,700 per qualifying child for 2025, subject to eligibility) are likewise only paid on a filed return. 

US citizens and resident aliens whose tax home and main place of business are outside the US and Puerto Rico on April 15 get an automatic extension to June 15 to file — but any tax owed is still due on April 15. No form is needed to claim this extension, though you should attach a brief statement to your Form 1040 saying you lived and worked abroad on the April 15 due date, and interest accrues on unpaid tax from April 15 regardless of the extra filing time. TFX's June 15 tax deadline guide covers the details.

Yes — beyond the automatic June 15 date, filing Form 4868 by June 15 extends your filing deadline to October 15, and in exceptional circumstances you can write to the IRS before October 15 to request a discretionary extension to December 15. A separate option, Form 2350, applies if you expect to meet the bona fide residence or physical presence test only after your filing deadline, and it must be filed on or before the regular deadline; none of these extensions stretch the time to pay, so tax owed is still due April 15 and accrues interest meanwhile.