--- title: "Tax Implications of Moving to USA from UK: 2026 Guide | Portunus" description: "The tax implications of moving to USA from UK are decided before you land — what to sort with PFICs, ISAs and residency timing before your US tax clock starts." datePublished: 2026-07-22T00:00:00.000Z canonical: https://www.portunusai.com/blog/tax-implications-moving-usa-uk source: https://www.portunusai.com/blog/tax-implications-moving-usa-uk --- # Tax Implications of Moving to USA from UK: 2026 Guide | Portunus The tax implications of moving to USA from UK are decided before you land — what to sort with PFICs, ISAs and residency timing before your US tax clock starts. ## Tax implications of moving to USA from UK: the quick answer The most important tax implications of moving to USA from UK are decided before you land, not after. Once you cross either the US green card test or the substantial presence test, all your worldwide income — UK employment, rental, dividends and pension — becomes reportable on your US federal return from that residency start date [4]. So the playbook is a sequence, not a rulebook: map both the UK Statutory Residence Test and the US residency tests against the actual calendar year you move, then decide what to sell, restructure or claim before the US clock starts. Most double-taxation and PFIC headaches are timing errors, not gaps in the tax code. Get the order right and you avoid problems that are impossible to unwind later. ## What changes the day you become a US tax resident There's a specific date the IRS cares about: your **residency start date**. If you get a green card, it's the first day you're physically present in the US as a lawful permanent resident. If you don't, it's usually the first day you're present during the year you meet the substantial presence test (roughly 183 days, counting all of the current year, a third of last year's days and a sixth of the year before). From that date, the US taxes you on income arising anywhere on earth. Your Manchester rental flat, your SIPP, your Vanguard UK fund, the dividends from your ISA — all of it now belongs on a US 1040 [4]. The UK, by contrast, taxes on a residence basis, so its claim on your foreign income generally ends when your UK residence does. That asymmetry is the whole game. Before your residency start date, you're still operating under UK rules, where certain gains, wrappers and disposals carry favourable or neutral treatment. After it, the same assets can attract punitive US tax and a stack of forms. Everything in this guide hangs on which side of that date an action falls. ## UK and US tax residency rules compared for the year you actually move You will be tax-resident in both countries during your move year. That's normal, and the two systems have mechanisms to carve up the year so you're not taxed twice on the same slice of income. On the UK side, the **Statutory Residence Test** decides whether you're resident, and **split-year treatment** can then split the tax year into a UK-resident part and a non-resident part. Where it applies, foreign income and gains arising after you leave fall completely outside the UK net for that year, provided you meet one of the statutory cases — such as starting full-time work overseas or ceasing to have a UK home [4]. This matters enormously, and it's easy to get wrong. On the US side, the substantial presence and green card tests fix your residency start date. The year of arrival is typically a **dual-status year**: a non-resident period before the start date and a resident period after it. You're taxed as a US resident only from the start date forward. When both countries claim you as resident for overlapping periods, the **UK–US double taxation agreement** provides tie-breaker rules — based on where your permanent home, centre of vital interests and habitual abode sit — to allocate residence to one country [1][5]. A closer-connection claim can sometimes keep you non-resident in the US for a year even after meeting substantial presence, if your tax home and stronger ties remain in the UK. Here's the part competitors skate over: split-year treatment is a one-time, claim-it-correctly-or-lose-it opportunity for your move year. It isn't a standing status you can invoke later. If you file it wrong, or fail to line up your departure date with the statutory case you're relying on, you can end up with UK tax on post-departure income that should have been excluded [4][5]. Map the UK split and the US start date together, in the same planning session, using the same calendar. ## What to do before you become a US tax resident: the pre-move checklist This is where money is won or lost. Every action below is worth more before your residency start date, and several become impossible or costly afterwards. **Deal with OEICs, unit trusts and investment trusts first.** The IRS classifies most UK-domiciled collective funds as **Passive Foreign Investment Companies (PFICs)** [1][4]. PFIC taxation is deliberately punitive: gains and certain distributions can be taxed at the highest ordinary rate with an interest charge stacked on top, plus an annual Form 8621 for each holding. Selling these funds while you're still solely UK-resident realises the gain under UK rules, often within your annual allowances, and lets you rebuy into US-compliant holdings later without dragging a PFIC into your US filings. Sell after your start date and you've imported the problem. **Decide what to do with your ISA.** The US does not recognise the ISA's tax-free status [1][4]. Worse, the funds inside it are usually PFICs, so an ISA can be doubly bad: no shelter and punitive treatment on the underlying holdings. Some people unwind ISAs entirely before moving; others hold cash ISAs (which are less problematic than stocks-and-shares ISAs) while liquidating the fund holdings. Whatever you choose, decide it before the start date so any disposal happens under UK rules. **Review your UK pensions, but don't rush to touch them.** SIPPs and workplace pensions generally get reasonable treatment under the treaty and are not PFICs in the way retail funds are, so pensions are usually a keep-and-report asset rather than a sell-before-you-go one [3]. The action here is documentation and reporting readiness, not liquidation. **Consider crystallising gains on property and investments while UK-resident.** If you hold assets sitting on large gains, realising them before the US start date can reset your cost basis for US purposes and use up UK allowances. This is highly fact-specific, but it's a lever that closes once you're taxed on worldwide gains as a US resident. Which of these close permanently? PFIC cleanup and ISA restructuring are effectively one-way doors. Once your residency start date passes, disposing of a PFIC is itself a taxable PFIC event, and the ISA wrapper gives you nothing. Sequence these first. If you're still costing out the whole move, the [cost of moving from UK to USA broken down by visa type](/blog/cost-of-moving-uk-to-usa) is worth reading alongside this, because tax restructuring costs belong in the same budget. ## What happens after you're a US tax resident: ongoing UK income and double tax Some UK income keeps flowing after you move, and it stays taxable in both countries in specific ways. UK **rental income** remains UK-taxable because UK-situated property is always within the UK net for non-residents. You report it to HMRC and again to the IRS, then use the **foreign tax credit** and the treaty to avoid paying twice on the same income [1][2][5]. UK **pensions** are generally taxed under treaty rules that usually give primary taxing rights to your country of residence, though government pensions differ. UK **dividends and interest** are reportable in the US, with treaty and credit mechanics reconciling the bill. Foreign tax credits do heavy lifting, but they don't erase double taxation. Timing mismatches between the UK tax year (April to April) and the US calendar year, plus PFIC income that gets taxed in ways the UK doesn't mirror, mean credits often fall short of full relief [4][5]. The US federal rate tops out at 37% on income over roughly $500,000, and a state like New York can add around 9% on top for high earners [3]. A UK credit computed against UK rates won't always cover a combined federal-plus-state US bill. Then there's the reporting layer, which is where the pre-move checklist pays off again. You must file an **FBAR** if the aggregate value of your non-US financial accounts exceeds $10,000 at any point in the year [1]. A single UK current account, an ISA and a pension together breach that easily, and dormant accounts count even if you never touch them. **FATCA Form 8938** adds a separate asset-reporting obligation with higher thresholds. The accounts you consolidated or closed before moving are accounts you no longer report or risk penalties on. One piece of good news on payroll: the **US–UK totalisation agreement** coordinates social security so you generally contribute to only one system at a time, avoiding double National Insurance and FICA on the same earnings [2]. That protects both your take-home pay and your long-term benefit entitlements. ## How your visa route changes the tax residency clock: E-2, L-1, O-1, EB-5, EB-2 NIW Nonimmigrant status does not pause the substantial presence count. This is the single biggest misconception among transferees. An **L-1** intracompany transferee or an **E-2** investor arriving mid-year will often trip substantial presence within that same year and become a US tax resident without meaning to [1][5]. The visa says "temporary"; the tax rules count days regardless. If you land in March on an L-1, you're very likely a US tax resident for that calendar year, and your pre-move window has already closed unless you planned around it. **O-1** holders face the same day-counting reality. Green-card-track applicants sit in a different position, and it's an advantage if used well. **EB-5** investors and **EB-2 NIW** self-petitioners typically have a longer runway between deciding to move and actually acquiring permanent residence. That extra time makes early PFIC and ISA cleanup more valuable, because you can stage disposals across UK tax years, use multiple annual allowances, and rebuild a US-compliant portfolio before the residency start date ever arrives [1]. If you're weighing which route fits, the [US visa guide for UK citizens](/blog/us-visa-uk-guide) breaks down the trajectories, and an [O-1 visa cost breakdown for UK applicants](/blog/o1-visa-cost) covers the numbers for that specific path. Look further ahead, too. If you take a green card and later surrender it after eight years or more, you can become a **covered expatriate** and face a US **exit tax** on unrealised gains. That's a reason to keep your investment structure clean throughout your time in the US, not just at entry [5]. An immigration attorney and a cross-border tax adviser should agree your timeline together — see this [guide to US immigration lawyers for UK residents](/blog/us-immigration-lawyer) if you're still choosing representation. ## Tax implications of moving to USA from UK: frequently asked questions ## Next steps: building your move-year tax sequence Fix your move date last, not first. Line up a UK/US cross-border tax adviser and your immigration attorney before you commit to a departure day, so the split-year claim, the PFIC and ISA cleanup, and the residency start date all fall in the right order. The errors that cost the most — an ISA sold too late, a fund disposed of after the start date, a split-year case that doesn't quite fit your departure — are the ones you cannot reverse once the calendar turns. Coordinating your movers, tax adviser and legal team around a single timeline is the cheapest insurance you'll buy on the whole relocation. And if plans change, the same discipline applies in reverse when [moving from the USA back to the UK](/moving-from-usa/uk). ### Sources ### Ready to Start Your E2 Application? Use our AI-powered platform to check your eligibility and begin your application process. [Check E2 Eligibility](/check-eligibility) ### Related Resources - /blog/cost-of-moving-uk-to-usa - Cost of Moving from UK to USA - The real cost of moving from UK to USA, broken into visa, shipping, arrival and first 90 days costs by visa route. - /blog/us-visa-uk-guide - US Visa Guide for UK Citizens - A complete map of the US visa categories available to UK citizens, from investor to work to family routes. - /blog/moving-to-usa-from-uk-complete-guide - Moving to the USA from the UK: Complete Guide - The full relocation playbook covering visas, shipping, housing, healthcare, and settling in. Disclaimer: For informational purposes only. Not legal or tax advice. Immigration outcomes are determined by the U.S. government, and tax treatment depends on individual circumstances. Consult a qualified cross-border tax adviser before making decisions about your move.