Introduction: H-1B Visa Tax and the British Professional
H-1B visa tax rules catch senior British professionals in a way that no domestic American guide explains. Furthermore, the standard advice online is written for a different reader entirely. Most of it assumes you have no assets outside America. However, a British banker, lawyer or technologist arriving in New York keeps UK accounts, a UK pension and often a UK property. Consequently, your position looks nothing like the one those guides describe. The result is predictable. Clients arrive having read widely and still get the basics wrong. Furthermore, the mistakes compound, because an H-1B visa tax error in year one distorts every year that follows.
Why H-1B Visa Tax Differs for Britons
Two systems reach you at once during your move year. Britain taxes you until you break residence. Meanwhile, America starts counting your days from the moment you land. Therefore, H-1B visa tax planning is really a sequencing problem rather than a filing problem. Moreover, the sequencing decisions are largely irreversible once the year closes.
The Popular Advice Is Wrong
Many H-1B guides state that you become a US resident from day one. That is simply incorrect. Specifically, residency depends on a day-count test, and most arrivals fail it in their first calendar year. Consequently, following that advice produces the wrong return and the wrong H-1B visa tax bill.
When You Actually Become a US Tax Resident
Residency drives everything else, so establish it first. Notably, your H-1B visa tax residency turns on arithmetic rather than on your visa category.
The Substantial Presence Test Formula
You count all days in the current year, a third of last year's days, and a sixth of the year before. You are resident if the total reaches 183. Additionally, you must be present at least 31 days in the current year. The IRS explains the substantial presence test in detail. Broadly, 122 days in each of three consecutive years also meets it.
No Exempt-Individual Shelter
Students and certain scholars can exclude their days from the count. H-1B holders cannot. Specifically, IRS guidance on the taxation of H-1B aliens confirms that the exempt-individual rules do not apply to you. Therefore, every day counts from arrival. Importantly, this also means your H-1B visa tax residency can begin mid-year.
Counting Your Days Correctly
Not every day in America counts against you. Specifically, you exclude days when a medical condition prevented you leaving after arriving healthy. Additionally, you exclude days commuting regularly from Canada or Mexico. However, part days generally count as whole days. Therefore, a fortnight of interviews before your start date can pull your H-1B visa tax residency forward by a year. In our experience, clients routinely forget those earlier visits.
Your Dual-Status First Year
Arrive in September and you will accrue roughly 122 days. That falls short of 183, so you are a nonresident for that year. Arrive in March and you cross the line during the summer. Consequently, you become a dual-status filer, taxed as a nonresident for part of the year and a resident for the rest. The IRS sets out how dual-status individuals are taxed, and the practical sting is severe. A dual-status filer gets no standard deduction at all.
The FICA Exemption Most Britons Never Claim
Here sits the most valuable H-1B visa tax point in this article. Furthermore, almost no competing guide mentions it.
How the Totalisation Agreement Works
America and Britain have a social security agreement. Consequently, you should pay into one system rather than both. IRS guidance on totalization agreements confirms that a worker from an agreement country may claim exemption from US Social Security and Medicare tax. Notably, the IRS states this directly on its own H-1B page.
Secondment Versus Direct US Hire
The exemption is not automatic, and the distinction is structural. If your UK employer seconds you to a US affiliate, you can normally remain in UK National Insurance for up to five years. Accordingly, you apply to HMRC for a certificate of continuing liability on form CA9107. However, a direct hire by a US employer gets nothing. Instead, FICA applies from the first pay packet.
What the Exemption Is Worth
The numbers justify the paperwork. Social Security runs at 6.2% on wages up to $184,500 for 2026. Additionally, Medicare takes 1.45% on everything, plus 0.9% above $200,000. Therefore, an employee earning $285,000 pays $11,439, $4,133 and $765 respectively. That totals $16,337 in a single year. Consequently, structuring the move as a secondment can be worth more than any other H-1B visa tax decision you make.
Apply Before You Move, Not After
Timing decides whether this works at all. Specifically, the certificate must be in place when your US work begins, because retrospective applications rarely succeed. Furthermore, your employer must genuinely second you rather than terminate and rehire you. Consequently, the H-1B visa tax saving depends on how your contract is drafted months earlier. We review the employment paperwork alongside the tax modelling for precisely that reason.
Your UK Accounts Become a US Reporting Problem
Residency does not merely change your rate. Rather, it switches on a reporting regime that most arrivals never see coming. This is where H-1B visa tax compliance becomes genuinely expensive to get wrong.
FBAR From Your First Resident Year
Once you are a US resident, the FBAR rules apply to your UK accounts. Specifically, you file once the aggregate maximum balance exceeds $10,000 at any point. That threshold is trivially low for a senior professional. Moreover, it captures current accounts, savings, ISAs and many pension arrangements. In our experience, a missed FBAR is the single commonest H-1B visa tax error among British arrivals.
Form 8938 and the Lower Domestic Thresholds
Form 8938 is separate, and living in America makes it worse. Americans abroad report above $200,000 at year end. By contrast, a taxpayer living in the United States reports above just $50,000 at year end, or $75,000 at any time. Joint filers report above $100,000 and $150,000. Consequently, the Form 8938 thresholds bite four times harder once you move.
Why Your ISA Stops Working
An ISA is tax-free in Britain and fully taxable in America. Furthermore, the United States does not recognise the wrapper at all. Therefore, your dividends and interest become ordinary US income. Additionally, a stocks and shares ISA holding UK funds can create punitive offshore fund treatment. We handle FBAR and FATCA reporting for exactly these situations.
Your UK Pension Needs Treaty Cover
A UK workplace pension raises its own questions once you move. Broadly, the treaty can protect the fund from current US tax on its growth. However, the protection is not automatic, and contributions made while you work in America receive only limited relief. Therefore, continuing to contribute after the move needs checking rather than assuming. Additionally, the pension may itself be reportable on both FBAR and Form 8938, which many arrivals overlook entirely.
What Happens on the UK Side
Britain does not release you automatically. Instead, you must break residence properly under the statutory residence test.
Split-Year Treatment and Form P85
Leaving mid-year usually gives you split-year treatment. Consequently, HMRC taxes your foreign income only for the resident portion. Case 1 covers those starting full-time work overseas, and HMRC sets out the conditions. Additionally, you should notify HMRC of your departure so your record is correct.
You Keep the UK Personal Allowance
British citizens retain the UK personal allowance as non-residents. That matters, because it shelters continuing UK income. Notably, this is not true for everyone. A US-only national in the opposite position gets no allowance at all. Therefore, your H-1B visa tax planning should account for UK income remaining sheltered.
UK Income That Still Gets Taxed
Leaving does not end your UK filing. Specifically, UK rental profits stay within the UK net, as do certain UK pension payments. Moreover, National Insurance treatment when you work abroad needs checking separately from income tax. Consequently, many arrivals file in both countries for several years.
Timing Your Departure Date
The UK and US tax years do not align, which creates planning room. Britain runs to 5 April, while America runs to 31 December. Consequently, a departure in the spring produces a very different H-1B visa tax outcome from one in the autumn. Specifically, leaving after 5 April starts a fresh UK year with a full personal allowance available against continuing UK income. Meanwhile, arriving late in the American year keeps you below the day-count threshold. Therefore, the gap between the two calendars is worth exploiting deliberately.
The Elections and the State Tax Trap
Two elections can transform your first-year bill. However, each carries a cost that guides rarely quantify.
The First-Year Choice
You may elect to be treated as a resident from your arrival date. Broadly, you must be present 31 consecutive days, and 75% of the days from that date to year end. Additionally, you must meet the substantial presence test in the following year. Consequently, the election converts a nonresident year into a dual-status year.
Electing Full-Year Residence With a Spouse
A married arrival has a stronger option. Specifically, you and your spouse can elect to be treated as US residents for the whole year, as IRS guidance on a nonresident alien spouse explains. That unlocks the joint standard deduction, which reaches $32,200 for 2026 under the IRS inflation adjustments. Furthermore, joint brackets are considerably wider.
The Cost of Electing
Nothing here is free. Electing full-year residence pulls your entire UK salary into the American return. Additionally, it triggers FBAR and Form 8938 for the whole year rather than part of it. Therefore, the election only wins where the standard deduction and joint rates outweigh the tax on your pre-arrival UK income. We model both outcomes before choosing, using the statutory residency definitions as the starting point.
State Tax Ignores the Treaty
Federal planning does not bind the states. Specifically, New York and California apply their own rules. California grants no foreign tax credit, no foreign earned income exclusion and no treaty relief whatsoever. Consequently, a Californian arrival can face state tax on income the treaty protects federally. New York applies its own residency tests too, including a statutory rule based on days and a permanent place of abode. Therefore, your H-1B visa tax planning must run at both federal and state level. Above all, choose your arrival state deliberately, because the difference reaches five figures for a senior professional.
A Worked Case Study With Real Numbers
Consider Rowan, a British quantitative analyst who moved from London to New York on an H-1B visa. Notably, they started work on 1 September 2026.
The Facts
Rowan earns $285,000 with a $60,000 signing bonus. Additionally, they hold UK accounts totalling £340,000, including an ISA and a workplace pension. Their 2026 US presence ran to 122 days. Consequently, they failed the substantial presence test for 2026 and were a nonresident for that year.
What Went Wrong
Rowan's UK adviser applied for a certificate of continuing liability. However, Rowan had been hired directly by the New York entity rather than seconded. Therefore, HMRC refused, and FICA applied in full. On 2027 wages of $285,000, that cost $16,337. Meanwhile, nobody mentioned FBAR. Rowan became a US resident in 2027 and missed the filing entirely.
The Resolution
We corrected both problems together. First, we filed the missed FBAR before any enquiry began, which kept the outcome penalty-free. Second, we reviewed the 2026 return, where Rowan had wrongly claimed a standard deduction as a nonresident. Furthermore, we modelled the full-year residence election and found it lost money, because the UK salary carried little creditable UK tax after allowances. Ultimately, correct sequencing before the move would have saved roughly $16,000 through a secondment structure. Two lessons stand out. First, the H-1B visa tax position had to be settled before the contract was signed, not afterwards. Second, the reporting obligations began the moment residency did, and nobody had diarised that date. Accordingly, we now fix both points at the outset of every inbound engagement.
How TaxYork Can Help
We prepare American and British returns together, which is what an H-1B visa tax position genuinely requires. Specifically, we model your residency start date before you book flights. Additionally, we test whether a secondment structure can preserve your National Insurance record and remove FICA. We then handle the reporting that follows, including US tax returns for expats and any catch-up filings. Our team at TaxYork covers both sides, so nothing falls between two sets of advisers. Additionally, we coordinate the UK departure position, including split-year treatment and any continuing UK filing. Where accounts have already gone unreported, we handle the catch-up through our offshore disclosure work. Consequently, an H-1B visa tax problem discovered late is still fixable on sensible terms.
Conclusion
H-1B visa tax outcomes for Britons turn on three decisions. First, your arrival date determines whether you file as a nonresident, a dual-status filer or a full-year resident. Second, the employment structure decides whether you pay $16,337 of FICA or nothing. Third, your UK accounts trigger reporting that begins the moment residency does. Ultimately, all three are cheap to plan and expensive to fix. Therefore, take advice before the move rather than in the following April. Above all, treat your H-1B visa tax position as part of the relocation package itself. The negotiating moment is when the offer is on the table, not once the first payslip arrives.
Contact Us
Plan the move before it happens. To model your residency date, your FICA position and your UK reporting together, book a consultation with our cross-border team. Email hello@taxyork.com or call 020 3488 8606. Furthermore, professional guidance from the ICAEW, the Chartered Institute of Taxation and AICPA and CIMA underpins how we work.
Disclaimer
This article provides general information about H-1B visa tax matters and related US-UK issues. It does not constitute tax or immigration advice for any specific situation. Thresholds, rates and published guidance change, and the correct treatment depends entirely on your own circumstances. Accordingly, you should obtain professional advice before acting. TaxYork accepts no liability for action taken in reliance on this material.