The Cross-Border Tax Guide to Returning to the US
Cross-border tax matters most in the months before you land, not after — the moment you re-establish US tax residency, FEIE proration, FBAR aggregation, PFIC exposure on UK funds, and Form 8938 thresholds all reset against you. Get the sequencing wrong, and a routine repatriation becomes a multi-year compliance headache.
By the TaxYork Cross-Border Tax Team — reviewed by a US-UK dual-qualified adviser (CPA / Enrolled Agent).
Cross-border tax returning to the US: what happens to my US taxes when I move back from the UK?
Your worldwide income becomes fully reportable again from the date you re-establish a US tax home, and the automatic overseas filing extension to 15 June disappears the moment you're physically resident. Several reliefs that made sense abroad — the Foreign Earned Income Exclusion chief among them — either shrink or stop applying entirely for the part of the year you're back on US soil.
The practical shift is less about new taxes and more about lost shelters. UK income you'd have excluded or credited against US tax while resident abroad now sits fully inside the US return, and accounts that were invisible below the higher "abroad" reporting thresholds can suddenly trigger disclosure once you're a US resident again — which is exactly why cross-border tax returning to the US questions tend to surface only after the move, when the reliefs have already narrowed.
The return-year filing deadline trap
The two-month automatic extension to 15 June only applies while your tax home and abode are outside the United States on 15 April, per the IRS FAQs on international individual tax matters. Once you've physically relocated, the standard 15 April deadline governs that return — filers who assume the June cushion still applies often discover it late, alongside a failure-to-file penalty clock already running.
Can I still claim the Foreign Earned Income Exclusion in my move year?
Yes, but only pro rata for the days you genuinely qualified while still abroad — you cannot claim the full annual figure in a year you relocate mid-year. The IRS prorates the exclusion by qualifying days under either the bona fide residence or physical presence test, so someone who returns on 1 September might only shelter a fraction of the 2026 maximum.
For 2026, the maximum Foreign Earned Income Exclusion is $132,900, up from $130,000 in 2025, as confirmed in the IRS's 2026 inflation adjustments release. The associated housing exclusion base limitation for 2026 sits at $39,870. Neither figure is available in full if your qualifying period abroad ends partway through the tax year — this is one of the most commonly miscited points in US cross-border tax return planning, with several competitor guides still quoting the stale $130,000 figure for 2026.
Item
2025
2026
FEIE maximum (full year)
$130,000
$132,900
FEIE housing exclusion base
$38,000 (approx.)
$39,870
US estate tax exclusion (per person)
$13,990,000
$15,000,000
Annual gift tax exclusion
$19,000
$19,000 (unchanged)
Gift to non-citizen spouse
$190,000 (approx.)
$194,000
Once the exclusion no longer covers your UK earnings for the US-resident portion of the year, the Foreign Earned Income Exclusion for wealthy dual filers explains how the same test interacts with the Foreign Tax Credit as a fallback, and how the two cannot be layered on the same dollar of income.
Do I still have to file an FBAR in the year I move back to the US?
Yes — the FBAR obligation is triggered by the highest aggregate balance of foreign accounts at any point during the calendar year, not by where you're living when you file. If your UK accounts crossed $10,000 in aggregate before you packed up, that year's FBAR is still due, and it doesn't matter that you were a US resident by the time FinCEN Form 114 falls due.
This catches out a lot of returning families who assume the reporting duty ends the moment they leave the UK. It doesn't, and it's one of the first things any proper cross-border tax checklist for returning to the US should flag before the moving trucks arrive. The FBAR obligations that follow you home cover the mechanics in more depth, including what happens if UK accounts are closed mid-year but still crossed the threshold earlier.
Form 8938 thresholds drop sharply on return.
While living abroad, the Form 8938 reporting thresholds are generous — up to $400,000/$600,000 for a married couple filing jointly. The moment you're a U.S. resident, those thresholds collapse to $100,000/$150,000 for the same couple, and single filers drop from $200,000/$300,000 to $50,000/$75,000. Accounts and UK investment holdings that never needed disclosure abroad can suddenly require it in your first US-resident year.
What happens to my UK ISA when I become a US resident again?
The ISA wrapper keeps its UK tax-free status with HMRC, but it gets zero recognition from the IRS — the US taxes what's inside the wrapper as if the ISA didn't exist. If the ISA holds UK unit trusts, OEICs or investment trusts, those holdings are almost always Passive Foreign Investment Companies for US tax purposes, and PFICs carry a punitive default tax regime under §1291.
PFIC elections and the ISA problem
A Qualified Electing Fund or mark-to-market election under Form 8621 can convert the default excess-distribution regime into something closer to ordinary annual taxation. Still, both elections generally need to be made from the first year you hold the PFIC — retrofitting them after several years of silent ownership is far messier and often more expensive. This is precisely the kind of wealth-specific trap that generic repatriation checklists skip, and it's a core reason why cross-border tax returns to the US require specialist review of the actual fund holdings, not just the account type.
Cash ISAs are simpler — they're just foreign bank accounts for US purposes, reportable on FBAR and Form 8938 but without the PFIC complication. The trouble sits specifically with stocks-and-shares ISAs holding UK-domiciled pooled funds.
What happens to my SIPP or UK pension when I move back to the US?
A UK SIPP generally keeps its treaty-protected pension status under Article 17/18 of the US-UK tax treaty, so periodic distributions are taxed in your country of residence rather than treated as a PFIC-style punitive vehicle. The wrinkle is the 25% UK tax-free pension commencement lump sum, which is not automatically tax-free for US purposes — treaty interpretation on this point is genuinely unsettled, and conservative advisers often treat the lump sum as US-taxable absent a clear treaty position.
Timing the lump-sum withdrawal before or after your return date can materially affect the US tax outcome, which is worth reading alongside planning pension withdrawals across the US-UK border before you touch the pot — pension timing is a recurring theme in cross-border tax returns, including US cases involving six-figure SIPPs.
Which US state should I move back to as a returning expat to avoid extra state tax?
States without an income tax — Florida, Texas, Nevada, Washington and a handful of others — sidestep the state residency question altogether and are the simplest landing points for returning expats. A small group of "sticky states," including California, New Mexico, New York, South Carolina, and Virginia, aggressively contest whether departing residents ever actually broke residency, and can attempt to claim back taxes on foreign-earned income from years you believed you'd left.
Ties that keep a sticky state interested
Retaining a driving license, a home, voter registration, or even a storage unit in a sticky state can be enough for that state's department of revenue to argue you never really left. Returning expats who plan to resettle in a different state should close out these ties deliberately before departure, not assume distance alone settles the question.
What if my UK tax affairs and FBARs weren't fully in order before I left?
Coming back onshore is the natural trigger to fix historical gaps, and the mechanics don't change just because you're now filing from a US address. Once you're physically resident, the non-residency track for Streamlined Filing closes, but the domestic version remains fully available.
Streamlined Domestic Offshore Procedures carry a 5% penalty on the single highest year-end aggregate value of unreported foreign financial assets across the relevant six years, alongside three years of amended returns and six years of FBARs, all requiring a non-wilful certification. Our walkthrough on catching up through Streamlined Filing Compliance Procedures sets out the Form 14654 mechanics in full, and for cases where a genuine reasonable-cause story exists rather than simple non-wilful conduct, reasonable cause as an alternative to streamlined is worth weighing against the 5% penalty route.
Do I have to pay UK tax after I leave the UK for the US?
HMRC applies split-year treatment automatically in your year of departure under the Statutory Residence Test, dividing the tax year into a UK part and an overseas part rather than taxing the whole year as UK-resident. Getting the qualifying Case right — full-time work abroad, accompanying a partner who qualifies, or ceasing to have a UK home — determines exactly where that split falls and which income lands in which part, as LITRG's guide to split-year treatment sets out.
Does moving back change my US estate and gift tax exposure?
Once you're a US citizen or domiciliary again, the US taxes your worldwide estate — not just US assets — at rates up to 40% above the exclusion. For 2026, that unified exclusion rises to $15,000,000 per person, up from $13,990,000 in 2025, following the permanent figure set under the One Big Beautiful Bill Act. The annual gift exclusion remains at $19,000 for 2026, unchanged from 2025, while gifts to a non-U.S. citizen spouse are subject to a separate $194,000 annual exclusion.
Anyone holding UK property, trusts or family wealth structured for UK IHT purposes should revisit that planning once US worldwide estate taxation applies again — a structure that made sense purely for UK inheritance tax can create unnecessary US exposure. For the details on how the exclusion interacts with jointly held UK-US assets, see how the US estate tax applies once you're back on US soil.
Case study: a mid-year return from London to New Jersey
A couple relocated from London to New Jersey on 1 September, having lived in the UK for six years. They had assumed their full $132,900 combined FEIE-equivalent shelter would apply for the year and hadn't realized the exclusion prorates to roughly 244 days abroad out of 365 — closer to $88,800 each, not the full annual figure. Their stocks-and-shares ISA held two UK OEICs that had never had a QEF election made, triggering a retroactive §1291 calculation stretching back three years, with interest charges layered on top of the tax. Their FBAR for the departure year was still outstanding because their UK joint account had briefly touched £14,000 in the spring before they'd started drawing it down for the move. Working through Streamlined Domestic Offshore Procedures, filing the prior three years of returns and six years of FBARs, and making a late (if imperfect) mark-to-market election on the OEICs going forward resolved the exposure at a fraction of the cost of ignoring it — but the retroactive PFIC calculation alone would have been avoidable with pre-departure planning.
Plan your return to the US before you pack the boxes.
The costliest mistakes in cross-border tax return planning for the US happen before the move, not after — PFIC elections that needed to be made years earlier, sticky-state ties left dangling, and FEIE proration nobody budgeted for. TaxYork's cross-border team builds a return-year tax plan around your actual accounts, pensions, and state destination, not a generic checklist. Get in touch before you set a moving date: hello@taxyork.com | 020 3488 8606 | taxyork.com