Expat tax rules: a guide for US citizens living overseas
US citizenship, not residence, is what creates the filing obligation. If you are American and your income clears the threshold, you file a return every year — whatever country you live in, whatever tax you already paid there. Most people abroad end up owing nothing; the return is still required.
Who has to file
The United States taxes its citizens and permanent residents on worldwide income. Living abroad does not change that. The filing threshold tracks the standard deduction for your filing status, and self-employment is stricter — net self-employment earnings of $400 or more require a return regardless of anything else.
Filing is not the same as owing. Between the Foreign Earned Income Exclusion and the foreign tax credit, most Americans abroad settle at zero US tax. The return is what proves it.
The deadlines that actually apply to you
15 April. The ordinary due date, and the date any tax owed starts accruing interest — an extension of time to file has never been an extension of time to pay.
15 June. An automatic two-month extension if you were living outside the United States on the ordinary due date. You do not apply for it; you attach a statement saying you qualify.
15 October. Available by filing Form 4868. I file these at no charge, because a request that takes two minutes should not carry a fee.
The FBAR runs on its own clock: due 15 April, with an automatic extension to 15 October that requires no request at all.
The forms that attach
Which forms travel with your return depends on the facts, not on a standard expat bundle. The table below is the short version of what usually attaches, and why.
The two mistakes I see most
The first is assuming that paying tax in the host country ends the US obligation. It does not — the return still has to be filed, and the relief is claimed on it rather than assumed.
The second is treating the exclusion as automatic. The Foreign Earned Income Exclusion is an election made on a filed return, and it depends on passing either the physical presence test or the bona fide residence test. Miss the qualifying period and the election is simply not available for that year.
IRC §911, §901 and §6012; IRS Publication 54; 31 CFR 1010.350; Form 4868 instructions. Dollar figures are stated for tax year 2025. Checked 13 September 2026.
Not sure which of these actually apply to you?
Twenty minutes, no obligation, with an Enrolled Agent rather than a salesperson.