US Expat Tax Deadlines for 2026: 15 June, 15 October and the December Extension

The US expat tax deadlines for 2026 run past the April date everyone knows. Americans abroad get an automatic extension to 15 June, can extend to 15 October with Form 4868, and may request a final two months to 15 December by letter. Tax owed, though, was payable from 15 April.

That last sentence is the whole trap. Every extension listed here buys time to file, not time to pay, and interest has been running on any 2025 balance since April. The nearest live deadline as this is written is 15 October 2026.

US expat tax deadlines for 2026 at a glance

The automatic extension to 15 June

The IRS grants an automatic two-month extension to citizens and resident aliens who, on the regular due date, live outside the United States and Puerto Rico with a tax home abroad, or are on military duty abroad. There is nothing to file in advance: you attach a statement to the return explaining which situation qualifies you.

It is genuinely automatic, but it does not stop interest. The IRS is blunt about that on its page for US citizens and resident aliens abroad: interest runs on tax not paid by the regular due date, extension or no extension.

Form 4868 to 15 October

If June is not enough, Form 4868 extends filing to 15 October. File it by the extended due date that applies to you and tick the box confirming you are out of the country, so the IRS knows the request follows the automatic two months. Our walk-through of Form 4868 covers the mechanics.

Estimate the tax honestly on the form. An extension based on a wildly low estimate can be treated as invalid, which reinstates the late-filing penalty from the original date.

The discretionary extension to 15 December

Beyond the six months, taxpayers out of the country can request a further two months — to 15 December for calendar-year filers. There is no form. You send the IRS a letter explaining why you need the extra time, and it must be sent by 15 October.

The IRS has discretion, and it tells you only if the request is denied. It is the right route when a foreign tax figure genuinely is not available yet, and the wrong route for ordinary delay.

The FBAR runs on its own clock

FinCEN Form 114 is due on 15 April, with an automatic extension to 15 October that you do not have to request. The threshold is an aggregate of more than $10,000 across your foreign accounts at any point in the year — a peak balance, not a year-end one, as set out on the IRS's FBAR page.

Form 8938 is different again: it goes with the income tax return, on whatever extended date applies, with much higher thresholds for people living abroad. The two are compared in FBAR versus Form 8938, and both sit within FBAR and FATCA reporting.

Do not forget the UK dates

UK Self Assessment for 2025-26 is due by 31 October 2026 on paper or 31 January 2027 online, with the balancing payment and the first payment on account also due on 31 January. GOV.UK lists them on its Self Assessment deadlines page.

The interaction matters for the foreign tax credit. If UK tax is not settled until January, claiming the credit on the accrual basis lets the US return match UK tax to the income it relates to, rather than to the date the money left your account.

What to do with the time left

• Pay first. If a 2025 balance is outstanding, pay it now to stop interest growing.
• File Form 4868 before 15 June if you know June will be tight.
• Gather P60s, payslips and P11Ds early — the calendar-year figures take rebuilding, as explained in reporting a UK salary on a US return.
• Check the FBAR peak balances across every account, including pensions and joint accounts.
• Write the December extension letter by 15 October if UK figures genuinely will not exist in time.
• Check state filing too: some states keep taxing you after you leave, covered in state taxes for US expats.

If you are behind by years rather than months, extensions are the wrong tool — the Streamlined Foreign Offshore Procedures exist for that, and the penalties are waived for non-willful failures. Tranzesta files both the US and UK returns so the dates line up. Book a consultation before 15 October.

Frequently Asked Questions

When is the US tax deadline for Americans living abroad?

Payment is due 15 April, but filing is automatically extended by two months to 15 June for citizens and resident aliens whose tax home is abroad on the regular due date. Filing Form 4868 extends that to 15 October, and a written request can extend it again to 15 December.

Do I have to request the automatic two-month extension?

No. It applies automatically if you live outside the United States and Puerto Rico with a tax home abroad, or are on military service abroad, on the regular due date. You attach a statement to the return explaining which situation qualified you, but you do not file anything in advance.

How do I get the extension to 15 December?

Send the IRS a letter explaining why you need the additional two months, and send it by 15 October. There is no form for this discretionary extension. The IRS grants it at its own discretion and notifies you only if the request is refused, so do not treat the December date as guaranteed.

Is the FBAR deadline the same as my tax return deadline?

No. FinCEN Form 114 is due on 15 April with an automatic extension to 15 October that needs no request. It is not affected by extensions to your income tax return, so a return extended to 15 December still leaves the FBAR due on 15 October.

Do extensions stop penalties and interest?

They stop the late-filing penalty, not interest. Interest accrues on any unpaid tax from the regular due date of 15 April, whatever extension you have. A late-payment penalty can also apply, although it may be avoided where at least 90% of the tax was paid by the due date and the balance is settled with the return.

What are the deadlines for an American living in Dubai?

The US dates are identical: 15 April to pay, 15 June automatically, 15 October with Form 4868 and 15 December on request, with the FBAR due 15 October. There is no personal income tax return in the UAE, but a UAE company you own has its own corporate tax return, generally due nine months after the end of its tax period.