The Complete Guide to US Expat Taxes: Every Form, Deadline, and Obligation Explained

I've reviewed thousands of returns for Americans scattered across every continent except Antarctica, and the question I hear most often isn't about a specific form or deduction. It's some version of: "Wait — I actually have to file US taxes from here?" The answer catches people off guard because it runs against how every other country on earth handles this. Most tax systems are residence-based: you owe tax where you live and work, full stop. The US is not one of them, and not knowing that is the single most common reason honest people end up years behind without meaning to.

Do You Actually Have to File?

Yes, in almost every case — and this surprises even long-term expats who've paid tax faithfully to their country of residence for years. The US taxes citizens and green card holders on worldwide income, a policy called citizenship-based taxation, and it applies regardless of where you live, where you earned the money, or whether you've set foot on US soil in a decade. If your income exceeds the standard filing threshold for your filing status — a threshold that's identical to what applies domestically — you have a US filing obligation.

Self-employed expats have a lower bar: $400 in net self-employment earnings triggers a filing requirement even if your total income would otherwise fall under the standard threshold, because self-employment tax is calculated separately from income tax. Filing doesn't necessarily mean owing. Between the Foreign Earned Income Exclusion, the Foreign Tax Credit, and tax treaties, most expats end up owing little or no US income tax — but the return itself still has to be filed to claim those benefits in the first place.

Who This Applies To

• US citizens living anywhere abroad — including dual citizens who have never lived in the US, sometimes called "Accidental Americans."
• Green card holders — the obligation continues as long as the green card is held, even after moving away, until it's formally abandoned or revoked through the proper immigration and tax process.
• Digital nomads and remote workers — location-independence doesn't change citizenship-based taxation; you owe based on who you are, not where your laptop happens to be that week.
• Non-resident spouses of US citizens — not automatically required to file, but a joint election under IRC §6013(g) can change that calculation and is worth discussing with a CPA rather than assuming.

Deadlines You Need to Know

The deadlines expats actually deal with differ from the domestic April 15 date most Americans think of, and mixing them up is an easy, avoidable mistake:

Two details trip people up here. First, the June 15 extension is automatic for anyone whose tax home and abode are outside the US — you don't file anything to get it, it simply applies. Second, that extension covers filing, not payment: if you owe tax, interest technically starts accruing from April 15 even though your paperwork isn't due until later.

Every Form You Might Need, Explained

Most domestic filers deal with one or two forms. Expats routinely deal with several, and knowing which ones apply to your situation before you start is most of the battle:

Not every expat needs every form on this list — a salaried employee with a single foreign bank account might only ever touch the first four. The point isn't to overwhelm you; it's to make sure you know which boxes actually apply to your situation before you (or a piece of consumer software) accidentally skip one.

FEIE vs. Foreign Tax Credit — The Core Decision

This is the single most consequential choice on most expat returns, and it's genuinely not obvious which one wins for a given year. The Foreign Earned Income Exclusion lets you exclude up to $132,900 of foreign-earned income from US tax in 2026 — but it only applies to earned income (wages, self-employment income), not to dividends, capital gains, or rental income, and it does nothing to reduce self-employment tax. The Foreign Tax Credit instead gives you a dollar-for-dollar credit against US tax for income tax you've already paid abroad, and it can apply to a broader range of income types.

The short version of how we decide: if you live in a low-or-no-tax country, the FEIE usually wins because there's little or no foreign tax to credit against. If you live in a higher-tax country than the US — much of Western Europe, for example — the Foreign Tax Credit often outperforms the FEIE and can even generate carryover credits for future years. Self-employed expats need to run both scenarios specifically, because the FEIE's SE-tax blind spot changes the math considerably.

FBAR and FATCA — Two Different Things People Confuse Constantly

These get lumped together so often that many expats assume they're the same filing. They aren't. FBAR reports to the Treasury's FinCEN division, triggers at a $10,000 aggregate balance across all foreign accounts at any point in the year, and is filed separately from your tax return. FATCA's Form 8938 reports to the IRS itself, has a considerably higher threshold for taxpayers living abroad, and is attached directly to Form 1040. Depending on your balances, you may need to file one, both, or neither — and yes, it's entirely possible to owe an FBAR filing with no FATCA requirement, or the reverse.

The most common FBAR error I catch in second-opinion reviews: people report their average account balance for the year instead of the highest balance at any single point, which is what the form actually asks for. It sounds minor. It isn't — it's the kind of discrepancy that can trigger a mismatch notice years later.

Do You Own a Foreign Business? There's a Separate Layer Here

If you hold 10% or more of a foreign corporation, Form 5471 is very likely required — separately from your personal return, with an automatic $10,000 penalty per missed form and a statute of limitations on your entire return that stays open until it's filed. If instead you're a foreign entrepreneur with a US LLC, Form 5472 applies, carrying an even steeper $25,000 automatic penalty. Both are frequently missed because taxpayers assume their local accountant's filings in their home country cover the US side — they never do.

State Tax Residency — The Part Most Guides Skip Entirely

Moving abroad ends your federal filing complexity in some ways, but it doesn't automatically end a state filing obligation. A handful of states — California and New York among the most aggressive — apply a domicile test that looks at ties you've kept behind: a driver's license you never cancelled, a home you still own, a car still registered in your name. Simply living overseas doesn't sever that connection on its own; establishing non-residency generally requires affirmative steps taken before or around the time you leave, not after a state tax bill arrives.

If You're Already Behind, Read This Section Twice

A significant share of the clients I work with didn't fail to file on purpose — they simply didn't know the requirement existed, sometimes for a decade or more. If that's you, the path forward is almost always the IRS Streamlined Filing Compliance Procedures: three years of tax returns, six years of FBARs, and a signed certification that your non-compliance was non-willful, in exchange for every failure-to-file, failure-to-pay, and FBAR penalty being waived. It is not an audit and it is not a criminal proceeding — it exists specifically for people in exactly this situation. I've written a complete, step-by-step guide to how the program works, including the SFOP vs. SDOP distinction and what "non-willful" actually means to the IRS, which is worth reading in full if this applies to you.

Paying the IRS — or Getting a Refund — Without a US Bank Account

This is a question I get constantly from long-term expats who closed their last US account years ago. A few practical options: international transfer services like Wise can issue you a US routing and account number to send a payment or receive a direct-deposit refund in USD; the IRS also accepts wire transfers from foreign banks directly; and a paper check mailed to your foreign address remains an option, though it's the slowest route and carries its own risk of loss in transit. None of these require you to open or maintain a US-based account.

DIY Software vs. an Expat CPA — When Each One Makes Sense

For a genuinely simple return — one employer, no foreign accounts above the FBAR threshold, no business interests — consumer tax software can technically get the job done. The moment your situation includes FBAR, FATCA, a foreign corporation, self-employment abroad, PFICs, or multiple years of catch-up filing, general-purpose software wasn't built to handle these international forms correctly, and the penalties attached to getting them wrong (or skipping them entirely) are some of the steepest in the tax code. That gap — not general tax prep, but the specific international forms DIY tools weren't designed for — is where a specialist earns their fee.

One honest limitation before the FAQ: this guide covers federal obligations in depth, and touches on state residency, but every state's rules differ and some situations warrant a conversation with local counsel in your specific state — something we're glad to help you think through during a free consultation rather than guess at generically here.

Frequently Asked Questions