US Tax Filing Deadlines for Americans Living in the UK (2025)

Americans in the UK get extra time to file their US tax return — but the deadlines differ from those in the US. This guide covers the automatic June extension, the October deadline, the FBAR due date, and estimated tax payment dates.

By Sam H., Founder & Lead Advisor

ACCA · ACA · Reviewed by Katie M. · 2026-07-30

As an American living in the UK, your US tax deadlines are not the same as those for people filing from inside the United States. An automatic extension applies to expats — but it only covers the filing itself, not any tax owed.

The short answer

Americans residing outside the US on 15 April get an automatic two-month filing extension to 15 June — no form required. A further extension to 15 October is available by filing Form 4868. Any tax owed still accrues interest from 15 April regardless of which extension you use.

The automatic June extension

If you are a US citizen or resident living and working outside the United States on 15 April, you automatically get two extra months to file your Form 1040, moving the deadline to 15 June. No form is needed. You attach a brief statement to your return confirming you qualified.

The extension is for filing only. If you owe US tax, interest begins accruing from 15 April. Paying any estimated balance by 15 April — even if you file later — limits the interest charge.

The October extension

Form 4868 extends the filing deadline to 15 October. File it by 15 June. The extension covers filing only — interest continues to run on unpaid tax from 15 April. A further discretionary extension to 15 December may be available by written request where overseas records prevent filing, but it is not automatic.

The FBAR deadline

The FBAR (FinCEN Form 114) is filed with FinCEN separately from the tax return. The deadline is 15 April with an automatic extension to 15 October — unlike the income tax extension, the FBAR October extension requires no form. If you have missed an FBAR, our Streamlined Filing guide explains the compliance routes available.

Estimated tax payments

Americans with income not subject to withholding — self-employment, UK rental income, investment income — generally need to make quarterly estimated payments to avoid an underpayment penalty. Payment dates: 15 April, 15 June, 15 September, and 15 January. The Foreign Tax Credit reduces US liability but is claimed on the return, not applied in advance, so the estimated payment calculation still applies during the year.

FATCA and Form 8938

Form 8938 is filed with Form 1040 and shares its deadline — 15 June for Americans abroad, extended to 15 October if Form 4868 is filed. Thresholds are higher for those living outside the US.

Penalties for missing deadlines

Failure-to-file: 5% of unpaid tax per month, capped at 25%. Failure-to-pay: 0.5% per month. Where reliefs reduce US tax to zero, percentage penalties are generally zero — but the return must still be filed. Flat penalties apply to missed information returns regardless of tax owed. Key expat dates are in our US expat tax deadlines tool.

A note on this guide

This reflects the 2025 tax year position. If you have outstanding returns or are uncertain whether the June extension applies, confirm your specific facts with a cross-border specialist before a deadline passes.

Frequently asked questions

Americans residing outside the United States on the regular 15 April deadline receive an automatic two-month extension to 15 June. No form is required. Any tax owed still accrues interest from 15 April — the extension is for filing, not payment.

Yes. Form 4868 extends the deadline to 15 October if filed by 15 June. A further discretionary extension to 15 December is available by written request. Extensions cover filing only — interest runs on unpaid tax from 15 April regardless.

The FBAR is due 15 April with an automatic extension to 15 October. No form is required for the FBAR extension. It is filed separately with FinCEN, not the IRS.

15 April, 15 June, 15 September, and 15 January. Americans with self-employment, rental, or investment income not subject to withholding typically need to make these payments to avoid an underpayment penalty.

No. The automatic extension applies to citizens residing outside the US on 15 April. If you had returned by that date, the standard April deadline applies.

The failure-to-file penalty is 5% of unpaid tax per month, capped at 25%. The failure-to-pay penalty is 0.5% per month. Where the Foreign Tax Credit reduces US tax to zero, percentage penalties are generally zero too — but the return must still be filed. FBAR penalties start at $10,000 per non-wilful violation.