Do Americans in the UK Have to File US Taxes?

The short answer: yes. If you are a US citizen or green card holder living in the UK and your income is above the filing threshold, you must file a US federal tax return every year. The US is one of the only countries that taxes by citizenship rather than residence, so the obligation follows you to London, Manchester, and everywhere else. The better news: once the return is prepared correctly, most Americans in the UK owe the IRS nothing.

Who has to file from the UK?

The filing requirement turns on status and income, not on where you live:

• US citizens, including dual citizens and people who have never lived in the US as adults.
• Green card holders, even ones living in the UK long term. The card keeps you in the US tax net until it is formally surrendered.
• Anyone above the threshold. For a single filer that is roughly $15,000 of worldwide income for 2025. For someone married filing separately, the threshold is just $5, which catches most Americans married to a non-US spouse. Students claimed as dependents have lower thresholds again, covered in our guide to American student UK tax.

Worldwide income means everything: UK salary, UK bank interest, dividends, rental income from a UK flat, self-employment income, and gains on UK investments. Paying UK tax on it first does not remove it from the US return; it just gives you credit to claim.

Why do most Americans in the UK owe no US tax?

Two mechanisms do the heavy lifting:

1. The Foreign Tax Credit (Form 1116). UK tax rates are generally higher than US rates, so the UK tax you already paid usually offsets the entire US bill on that income. Unused credits can carry forward for ten years.
2. The Foreign Earned Income Exclusion (Form 2555). As an alternative for earned income, you can exclude roughly $130,000 of wages from US tax if you meet the bona fide residence or physical presence test.

Which route saves more depends on your income mix, and the choice affects other things, such as IRA eligibility and the refundable child tax credit. It is worth modeling both every year rather than repeating whatever last year's return did. Our US tax return service does exactly that.

What else has to be filed besides the Form 1040?

The information reporting is where Americans abroad get caught out, because the penalties attach to the forms, not to any tax owed:

• FBAR (FinCEN Form 114), if your non-US accounts together exceeded $10,000 at any point in the year. That includes current accounts, savings, ISAs, and many pensions.
• Form 8938 (FATCA), at higher thresholds, filed with the return itself.
• Form 8621, for each PFIC you hold. Most UK funds and stocks-and-shares ISAs are PFICs, which is a problem worth reading about separately.
• Forms 3520/3520-A, for certain UK trusts and large gifts or inheritances from non-US persons.

For the full picture on both sides of the Atlantic, see our checklist of tax obligations for Americans living in the UK.

When are the deadlines?

Americans abroad get an automatic filing extension to June 15, and can extend to October 15 with Form 4868. Interest on any tax owed still runs from April 15. The FBAR is due April 15 with an automatic extension to October 15. The UK side runs on its own calendar: online Self Assessment is due 31 January after the 5 April tax year end, which is why the two returns need to be sequenced deliberately.

What if you have not been filing?

Do not panic, and do not file five years of returns cold. The Streamlined Foreign Offshore Procedures exist for exactly this situation: three years of returns, six years of FBARs, and a certification that the failure was non-willful, with all late-filing penalties waived. Most people who catch up this way owe little or nothing. The program is only available before the IRS contacts you first, so timing matters.

The bottom line

Filing from the UK is an obligation, not usually a bill. The risk is not the tax; it is unfiled information forms, mispriced investments like ISAs, and two accountants who each see only half the picture. One team preparing both returns removes most of the risk at the source.

Official sources

The rules described here come from the tax authorities themselves. Thresholds and procedures change, so check the current guidance before you file:

• IRS: Foreign Earned Income Exclusion
• IRS: Foreign Tax Credit
• GOV.UK: Self Assessment tax returns