Federal US tax deadlines and forms you need to consider

The following table provides American citizens with the key dates, deadlines and forms they must be aware of when living outside the United States.

Even if you owe no tax in the US, American citizens must still file annually due to the Foreign Earned Income Exclusion (FEIE) or Foreign Tax Credit (FTC) requirements – ignorance is not an excuse and will not help you avoid being penalised.

Date	Deadline/Event	Forms to be aware of and maybe completed
March 15	Deadline for declaring foreign trusts and partnerships	Form 3520-A Form 1065
April 15	Standard U.S. tax deadline if living in the U.S. or choose not to take extension. FBAR Deadline - for foreign financial accounts over $10,000. Tax payment deadline: Any tax owed is due even if you file later using extensions.	Form 1040 FinCEN Form 114
June 15 (moved to June 16 in 2025 due to June 15 being a Sunday)	Automatic expat filing extension deadline (automatic 2-month extension from April 15 for US citizens living outside the US) File Form 1040 or request a further extension (Form 4868).	Form 1040 Form 4868 (if filing a further extension)
October 15	Extended filing deadline if Form 4868 was submitted by June 16. Extended deadline for FBAR (FinCEN 114), if not filed by April.	Form 1040 FinCEN Form 114
December 31	Deadline to take Required Minimum Distributions (RMDs)

Important UK tax deadlines to be aware of

In addition to understanding US tax deadlines and forms, you will also need to understand and consider the key dates in the UK tax year. It’s also important to remember that the UK financial year begins on April 6^th, which brings a little bit of added complexity.

Date	Deadline/Event
April 6	Start of new UK tax year.
October 5	Deadline to register for Self Assessment with HMRC if you're a new filer.
October 31	Paper tax return filing deadline for previous UK tax year.
January 31	Online Self Assessment filing deadline and final payment due for previous tax year. First payment on account for current tax year is also due, if applicable.
April 5	End of the UK tax year.
July 31	Second payment on account for the current tax year.

American expats who are UK tax residents usually file both US and UK tax returns. Treaties and credits help avoid double taxation.

Optional/additional US tax forms to be aware of

Form	Purpose	Deadline
Form 8938 (FATCA)	Report foreign financial assets over thresholds ($50,000+)	With tax return
Form 2555	Claim Foreign Earned Income Exclusion (FEIE)	With tax return
Form 1116	Claim Foreign Tax Credit	With tax return
Form 3520/3520-A	Report foreign trusts or foreign gifts over thresholds	March 15 / April 15 (16 in 2025)

Get help with your US and UK tax obligations

Understanding and managing your tax obligations across the US and UK can be complex, especially if you try to do it yourself. While this article highlights what you need to do it and when you need to do it, it's possible to miss deadlines, completely forms incorrectly, and risk unnecessary double taxation.

If you're unsure about your filing or want peace of mind that you're fully compliant, we can help.

Request a free introduction and discovery call with a trusted, independent tax adviser who specialises in supporting American expats living in the UK. There’s no obligation following the discovery call, but it should help reduce your stress and give you the confidence that everything is taken care of.

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Key US and UK tax deadlines for American expats living in the UK

Federal US tax deadlines and forms you need to consider

Important UK tax deadlines to be aware of

Optional/additional US tax forms to be aware of

Get help with your US and UK tax obligations

Reducing the stress and complexity of living abroad