What Americans abroad need to know about the October 15th tax deadline

Thursday, October 15th, 2026, is the last day for Americans abroad who requested additional time to file your 2025 federal tax return. If you also need to file an FBAR, it's due on the same date.

What trips up many US expats is what the extension actually covers: it gives you more time to file, no more time to pay.

In this guide, we break down what Americans abroad need to know about the October 15th deadline for both your tax return and your FBAR, why filing matters even if you owe nothing, and what happens if you don't file in time.

What October 15th Covers

The October 15th tax deadline is about filing, and only filing.

As a US citizen living abroad, you get an automatic two-month filing extension to June 15th, with no paperwork required. Filing Form 4868 by that date added another four months, moving your due date to October 15th.

Your FBAR is due the same day, although it's a separate filing that doesn't go to the IRS at all (more on FBARs below).

Don’t leave it until the deadline: start your return today

What the October 15th extension doesn't cover 

Living abroad doesn't move the payment date. Whatever you owed on your 2025 return was due April 15th, 2026, and both interest and the late-payment penalty run from that date, not from June 15th or October 15th.

Interest is compounded daily and continues to accrue on any unpaid tax until the balance is paid in full. For example, at the current rate of 7 percent a year, a $6,000 balance carried from April 15th to October 15th works out to a little over $200 in interest, and that's before any penalties.

The late payment penalty is separate: 0.5 percent of the unpaid tax for each month or part of a month it goes unpaid, up to a maximum of 25 percent. Form 4868 puts it plainly: "Form 4868 doesn't extend the time to pay taxes."

If you haven't paid, paying now stops the interest from growing. Use IRS Direct Pay, or apply for a payment plan if you can't pay in full.

Still need to file? Get started before October 15th

October 15th is also the FBAR Deadline

If the combined value of your foreign financial accounts exceeds $10,000 at any point in 2025, you may need to file the Report of Foreign Bank and Financial Accounts (FBAR).

This can include accounts you have signature or other authority over but don’t own, such as certain business accounts, as well as accounts you closed during the year.

The FBAR is separate from your US tax return. It is filed electronically with the Financial Crimes Enforcement Network (FinCEN) through the BSA E-Filing System, rather than as part of your return to the IRS.

The good news is that the October 15th FBAR extension is automatic. If you missed the usual April 15th deadline, there’s no additional form to submit or extension to request.

Missing it is expensive. The maximum penalty for a non-willful violation is $16,536, and since the Supreme Court's decision in the 2023 case, Bittner v. United States, it applies per report rather than per account.

What happens if you miss the October 15th deadline?

Your return is late, and the failure-to-file penalty is 5 percent of any unpaid tax for each month, or part of a month, that it remains outstanding, up to 25 percent.

For most Americans abroad, that may come to nothing, because expat tax breaks like the Foreign Tax Credit and the Foreign Earned Income Exclusion can significantly reduce what you owe, and in many cases bring it to zero.

But those benefits only apply if you claim them, and to claim them, you must file, even if you expect your US tax bill to be zero.

If October 15th hasn't arrived yet and you know you won't make it, you may have one more option.

Americans abroad can request a further extension to December 15th by writing to the IRS with the reason. It's discretionary, and you'll only hear back if it's refused.

What if you didn't file Form 4868?

If you didn't file Form 4868, you can still file your return, and it's worth doing as soon as you can. Without the extension, your 2025 return was due June 15th, so it's already late, and if you have unpaid tax the failure-to-file penalty builds each month until it reaches 25 percent. Filing is what stop it.

Fortunately, you may not be charged at all. The IRS now applies penalty relief automatically through a programme called Automatic Exemption from Penalty, which is replacing the old First-Time Abatement process and applies to eligible 2025 returns.

If you meet the eligibility requirements, including filing and paying on time for the three prior years, the relief applies automatically without a separate request. It doesn't cover penalties for the FBAR or other international information returns, which have their own procedures.

If you're behind on several years rather than one, the Streamlined Filing Compliance Procedures may offer a route back. You file the last three years of returns and six years of FBARs, certify that your non-compliance was non-willful, and if you qualify, the penalties are waived.

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The bottom line

October 15th is manageable if you start now, and remember: filing is how you claim the expat tax benefits that could reduce or eliminate your US tax bill.

MyExpatTaxes was built by Americans living abroad, for Americans living abroad. You get the most affordable DIY expat tax software, plus flat-priced tax services with trusted tax professionals. File your return and your FBAR in one place.

See the plans and prices, or create a free account today to stay compliant and file your 2025 return without the stress.