Do I Still Have to File US Taxes if I Live in the UK?

The rule nobody tells you before you move

The United States is nearly unique in taxing by citizenship rather than residence. A US citizen — or a Green Card holder, whose card keeps them a US tax resident until it is formally surrendered — remains inside the US filing system no matter where in the world they live, and no matter where their income arises. Moving to the UK changes which country you live in; it changes nothing about the IRS's view of you.

So the honest answer to the question in the title is: yes, almost certainly, if your income is above the normal filing thresholds. Those thresholds are modest, and two of them are startling: a US citizen who is married to a non-American and files separately must file with income of just $5, and anyone with net self-employment earnings of $400 or more must file on that basis alone. A freelancer's first serious month in London can be enough.

Filing is not the same as paying

Here is the part that deflates the panic. The US system contains two main mechanisms that prevent Americans abroad from being taxed twice: the foreign tax credit, which offsets US tax with the UK tax you have already paid, and the foreign earned income exclusion, which removes earned income up to an inflation-adjusted cap (see the current IRS figures) from US tax entirely.

Because UK rates on most income are at least as high as US rates, the foreign tax credit alone frequently reduces the US bill on UK salary to zero — often with credits left over. The typical American in Britain files a return showing little or no tax due. The return still matters, though: these mechanisms are claimed on it, not granted automatically, and an unfiled year protects nothing.

The genuine US tax exposures for UK-based Americans come from mismatches, not from salary — income the UK shelters but the US does not. ISAs are the emblematic case: invisible to HMRC, fully taxable to the IRS, and often holding investments the US taxes punitively. If a UK-based American ends up writing a real cheque to the IRS, something in this category is usually why.

The deadlines, which are kinder than you think

Americans abroad get more time than Americans at home:

Interest can still run from April on any tax actually due, so the extensions buy time to file more than time to pay. Meanwhile your UK obligations run on their own calendar entirely — a tax year ending 5 April and online Self Assessment due 31 January — which is one reason cross-border filers benefit from having both returns prepared by the same hands.

The FBAR: the other annual obligation

Separate from the tax return sits the FBAR — a report of your non-US financial accounts filed with FinCEN. It is triggered when the combined highest balances of all your non-US accounts exceed $10,000 at any point in the year, a threshold that has never been adjusted for inflation and that an ordinary salary account crosses easily. It costs nothing to file and creates no tax; the risk sits entirely in ignoring it, because FBAR penalties are among the harshest in the US system. A second disclosure, Form 8938, is filed with the return itself under FATCA at higher thresholds — it overlaps the FBAR without replacing it, so many expats report the same accounts twice.

If you have already missed years

Discovering the filing obligation years late is so common that the IRS built a dedicated route for it. The Streamlined Foreign Offshore Procedures generally allow non-wilful taxpayers abroad to catch up with three years of returns and six years of FBARs, penalties waived, provided they come forward before the IRS raises the issue. Most people who use it owe far less than they feared — frequently nothing.

What consistently makes things worse is improvisation: quietly filing a stack of late returns, or starting fresh this year and hoping the past goes unnoticed. The defined routes exist; use one.

And one more American layer: your former state

Federal filing is not always the end of it. Most US states release residents who genuinely leave, but a few are known for clinging — continuing to expect returns until ties like driving licences, voter registration and in-state property are affirmatively severed. State obligations sit entirely outside the federal reliefs: the foreign tax credit and the exclusion are federal mechanisms, and a state that still considers you a resident is unmoved by either. If you moved to the UK from one of the stickier states, an hour spent confirming your state exit was clean is an hour well spent.

Where that leaves you

If you are American and living in the UK, assume you have a US filing obligation until someone qualified confirms otherwise. Assume the FBAR applies. Then take the larger reassurance: for most people this is an administrative burden, not a financial one — and with both returns prepared together, a fairly light administrative burden at that. If your filing history has gaps, or you have never filed at all, a consultation will tell you exactly how small the fix can be.