Missed UK Self Assessment: American Arrival-Year Guide

A missed UK Self Assessment in the arrival year is usually repairable. Split-year treatment applies by statute when a Schedule 45 case is met, so pre-arrival foreign income, gains and bonus can fall outside UK tax, but only a return with SA109 reports that result and recovers overcharged PAYE.

The usual fact pattern is simple. A US executive or founder lands in London, joins a UK payroll, sees 45% deducted from a bonus earned in New York, keeps a US brokerage account running, and assumes the employer has dealt with the UK. Nobody files. At Jungle Tax we see the consequence run in both directions: UK tax overpaid on the bonus and UK tax underpaid on the brokerage account, inside a single unfiled year.

Published guidance tends to explain the split-year cases or the first-year FIG regime as a forward-looking matter. What it rarely addresses is the year already gone: which penalty rules actually apply when no notice to file was issued, which claim clocks are running, and what a UK refund does to the US foreign tax credit. This guide is built around those three gaps. It concerns arrivals only; departure years follow different cases.

Why did PAYE seem to settle the arrival year?

PAYE taxes what passes through a UK payroll, at a code that knows nothing about your residence date or your foreign accounts. It cannot see a US dividend, a sale of stock or the months you spent in New York before the move. Three separate errors can sit behind a clean P60:

• Overcharge: a bonus for pre-arrival overseas duties taxed in full because it was paid after you joined the UK payroll.
• Undercharge: foreign income and gains arising in the UK part of the year that no employer reported.
• Silence: a split year that applied as a matter of law but was never reported, leaving HMRC to treat you as resident for the entire tax year if it ever reviews the record.

Under GOV.UK's Self Assessment rules, someone new to the system with a return to make must tell HMRC by 5 October after the tax year. For most relocating Americans with a live brokerage account, that deadline was the first thing missed.

Is split-year treatment automatic, or do I have to claim it?

Both statements found online are half right. Under Finance Act 2013 Schedule 45, Part 3, a tax year is a split year when you are UK resident for the year and your circumstances fall within one of the cases (paragraph 43). HMRC's manual at RFIG21010 is direct: the individual has no choice. You cannot opt in where a case is not met, and you cannot opt out where it is.

Reporting is a separate duty. The SA109 pages and notes for 2025-26 ask for:

• Box 3: a mark that your circumstances meet the split-year criteria.
• Box 3.1: a mark if more than one case applies.
• Box 6: the date from which the UK part begins.
• Box 10: UK midnights in the overseas part only.
• Box 12: UK ties in the overseas part, where Case 4 or Case 8 is relied upon.
• Box 54: which case applies, in free text.

The same notes say online filing of these pages requires commercial software or an agent. Box references change, so work from the form for the actual year being filed. The first threshold is also often skipped: you must be UK resident for the year under the Statutory Residence Test in RDR3, and non-resident for the prior year. No residence in the year means no split, and no arrival-year charge to split.

Which arrival case fits an American who moved to London?

Five cases cover arrivals. Before the UK part starts, Cases 4, 5 and 8 also require that you did not have sufficient UK ties, using day limits reduced by month as set out in the manual.

Case 4: only home in the UK

RFIG21150 requires that all your homes are in the UK from a point in the year through to 5 April. A retained Manhattan apartment that still counts as a home ordinarily defeats it.

Case 5: starting full-time work in the UK

Per RFIG21170 and paragraph 48, you need a 365-day period beginning on a day of more than three hours' UK work, with sufficient UK hours, no significant break and at least 75% of working days being UK days. Paragraph 9's hours test and the deductions it allows must be calculated, not assumed.

Case 6 and Case 7: returning workers and their partners

Case 6 needs non-residence under the third automatic overseas test in the prior year and UK residence in at least one of the four years before that. A first-time arrival cannot use it. Case 7 is confined to the partner of a Case 6 individual, so the spouse of a first-time Case 5 executive must qualify on their own facts.

Case 8: starting to have a home in the UK

RFIG21270 allows a US home to continue, but the UK home must then be kept for the rest of the year and the whole of the next, and the next year must be UK resident and not itself split.

When more than one case applies

Under paragraph 55 and RFIG21030, the case with the earliest split-year date generally governs among Cases 4, 5 and 8. This is not a preference. It can move the start of the UK part to a date before your first day in the London office, and any stock sale in that gap falls on the UK side.

Decision table: arrival patterns we constructed

Illustrative arrival	Likely result	UK part starts	What to test
London lease from 20 August, payroll from 1 September, New York apartment retained	Cases 5 and 8; Case 4 fails	20 August (earliest date)	Case 8 needs the UK home kept through the following year
New York home sold, moves to a London home in June, no UK job	Case 4, possibly Case 8	Date the conditions are first met	Sale completion date, other homes, reduced ties limits
Serviced apartment and full-time UK role from 1 November; no real home until next summer	Case 5 if work tests pass	First day of qualifying period	Whether temporary accommodation is a home; 75% and hours tests
Founder works about 25 hours a week in London, keeps US home, rents only short lets	Possibly no case	None: whole year UK resident if SRT met	Hours calculation, home evidence, full-year worldwide exposure
Partner of a first-time executive follows four months later	Not Case 7; test 4, 5 and 8 separately	Partner's own date	Partner's own residence, ties and home facts
Former UK resident returns after one full US work year	Case 6 may compete with Case 5	Earlier date rule, otherwise Case 6	Prior-year third automatic overseas test, four-year look-back
Arrives in February with too little to become resident that tax year	No split year; not resident that year	Not applicable	SRT day count; next year may be the arrival year

What falls outside UK tax if the case is met?

Schedule 45 works through the charging provisions, head by head. Foreign employment earnings for the overseas part are excluded unless they relate to UK duties (paragraph 58). Income from savings and investments arising in the overseas part is treated as non-UK (paragraphs 83 and 84), and gains in the overseas part are generally not charged, subject to the statutory exceptions (paragraph 93). The SA109 notes summarise the outcome as paying tax on income arising in the UK part, but non-residents can still be charged on some UK-source income, so overseas-part UK income needs its own check.

If no case is met, none of this applies. Pre-arrival dividends and the entire tax year's gains are then in charge, subject to any treaty relief, and the remedy is a different analysis entirely.

The pre-arrival bonus

Attribution is the issue, not the payment date. HMRC's EIM40006 says split-year treatment cannot remove earnings that relate in substance to UK service, and a split between periods should not necessarily be made on a time basis. In practice that means obtaining the plan terms, the performance period, the deferral conditions and a letter from the employer. A bonus reflecting a London-related role, signing incentive or a performance period running beyond arrival needs a reasoned apportionment. Share awards need separate analysis. National Insurance is a separate regime and is not recovered through SA109.

How do FIG and the remittance basis change the UK part?

Do not transfer the current regime back to an earlier year. The relevant date is 6 April 2025.

Arrival year	Notify by	Online filing date	UK-part foreign income regime	Remaining FIG years	Key claim date
2022-23	5 Oct 2023	31 Jan 2024	Arising, or remittance basis claim	2025-26 only	Remittance claim: 5 Apr 2027
2023-24	5 Oct 2024	31 Jan 2025	Arising, or remittance basis claim	2025-26, 2026-27	Remittance claim: 5 Apr 2028
2024-25	5 Oct 2025	31 Jan 2026	Arising, or remittance basis claim	2025-26 to 2027-28	Remittance claim: 5 Apr 2029
2025-26	5 Oct 2026	31 Jan 2027	Arising, or FIG claim	2025-26 to 2028-29	FIG claim: 31 Jan 2028

Dates are derived from the rules cited below and should be confirmed against the taxpayer's own notice position. An arrival in 2025-26 has passed the notification date but is still within the online filing date at the time of writing, which makes it the cheapest year to correct.

Years before 6 April 2025

An American arriving in those years was commonly non-UK domiciled, but this should be evidenced rather than presumed. RDRM32030 confirms the general limit: no more than four years after the end of the tax year. A late claim can therefore still be available on a late return, but it costs the personal allowance and capital gains annual exempt amount and leaves remitted amounts chargeable. Transferring post-arrival brokerage proceeds to fund a London home is exactly the kind of movement to trace. The temporary repatriation facility may be relevant to pre-2025 remittance basis amounts; it requires its own designation.

Years from 6 April 2025

Under RFIG44000, split-year treatment and treaty non-residence are disregarded in testing the regime. Two consequences follow. The split arrival year counts as a full residence year for the 10-year test and starts the four-year window, whenever in the year you landed. And for an arrival before April 2025, the window has already been running: relief is unavailable for income arising before 6 April 2025.

Per HS266, the claim for 2025-26 must be made by 31 January 2028, year by year, on SA109 boxes 28 and 29. It removes the personal allowance and annual exempt amount, removes foreign tax credit relief on relieved income, and does not cover relevant foreign earnings. Overseas Workday Relief has its own SA109 election. A person who waits for 2025-26 to be chased could lose a valuable claim simply through elapsed time.

Worked example: London from August 2024 (illustrative)

All names, dates and figures are illustrative. A US citizen executive, non-resident for the preceding 10 years, has these facts for 2024-25:

• Works in New York from 6 April until the move; retains the New York apartment as a home.
• Moves into a two-year London lease on 20 August 2024; starts a full-time London role on 1 September 2024.
• Receives a £240,000 bonus through UK payroll in September, for a performance period wholly before arrival and wholly on US duties. PAYE at 45%: £108,000.
• UK salary 1 September to 5 April: £210,000, fully through PAYE.
• US dividends: £22,000 before 20 August; £48,000 after.
• US stock gains: £310,000 on 12 June 2024; £180,000 on 25 August 2024.

Cases 5 and 8 both apply. The earliest date governs, so the UK part starts on 20 August, not 1 September. The 25 August gain, realised before the first working day in London, falls in the UK part. The return shows box 3, box 3.1, box 6 as 20 August 2024, and both cases in box 54.

Item, UK tax before foreign tax relief	If no case met	Split year, arising basis	Split year, remittance claim, nothing remitted
Bonus £240,000 at 45%	£108,000	£0	£0
Dividends before 20 Aug, £22,000 at 39.35%	£8,657	£0	£0
Dividends after 20 Aug, £48,000 at 39.35%	£18,888	£18,888	£0
June gain, £310,000 at 20%	£62,000	£0	£0
August gain, £180,000 less £3,000 at 20%	£35,400	£35,400	£0
Total on these items	£232,945	£54,288	£0
PAYE paid on bonus	£108,000	£108,000	£108,000
Further tax or (repayment)	£124,945	(£53,712)	(£108,000)

The salary is unaffected in all columns, the personal allowance is nil in all columns at this income, and the calculation is simplified to the 2024-25 rates shown. The spread between the first two columns, about £179,000 before any foreign tax relief, turns on evidence of a home and working dates rather than on any election. In the third column, any money later brought to the UK would be taxed under the remittance rules. For 2025-26, this taxpayer is in year two of the window and must separately decide whether a FIG claim belongs on that return by 31 January 2028.

What are the penalties when nobody filed?

The penalty analysis turns on one document many clients have never checked: whether HMRC ever issued a notice to file.

• Notice issued: the GOV.UK late-return scale applies: £100, then £10 a day for up to 90 days after three months, then the greater of 5% of tax due or £300 at six months and again at twelve. Reasonable excuse appeals are heard only once the return is in.
• No notice issued: a notice given after 31 October following the tax year generally sets the filing date three months later under section 8 TMA 1970, so late-filing penalties should not have started running. The exposure is instead failure to notify under FA 2008 Schedule 41.
• Failure to notify: charged on tax still unpaid after 31 January following the year. Where PAYE already exceeds total liability, that base may be nil. Otherwise behaviour and disclosure matter: up to 30% for non-deliberate failures and up to 100% for deliberate and concealed ones, before reductions for unprompted disclosure, with possible uplifts for some offshore matters.
• Late payment: 5% at 30 days, six months and twelve months where it applies, plus interest. Interest runs on underpaid tax regardless of penalties.

Time limits run in both directions. Recovery of overpaid tax is generally limited to four years after the tax year under Schedule 1AB TMA 1970, so a 2022-23 repayment needs attention before 5 April 2027. HMRC's assessing windows are longer, reaching 20 years where deliberate behaviour or failure to notify is involved. Where UK-part foreign liabilities exist, compare a late return route with the Worldwide Disclosure Facility before contacting HMRC, particularly as US-held accounts may be visible to HMRC under the reciprocal US-UK reporting arrangements.

How does the same year look on the US Form 1040?

For a citizen, there is no arrival year. The IRS explains that dual status concerns residency for US purposes, not citizenship. A US citizen remains taxable on worldwide income from 1 January to 31 December, so articles about a part-year US return do not apply, whichever date HMRC accepts for the UK part. See our US tax services for how the return is assembled.

Point	UK / HMRC	US / IRS (citizen)
Year	6 April to 5 April, may be split	Calendar year, never split for a citizen
Pre-arrival bonus	Excluded to the extent the case and attribution permit	Fully reportable on Form 1040
Brokerage income before UK part	Generally outside charge	Fully taxable
Brokerage income in UK part	Arising; pre-2025 remittance claim; or FIG claim from 2025-26	Fully taxable either way
Double tax relief	Foreign tax credit relief, not on FIG-relieved income	Form 1116, or Form 2555 for qualifying earned income
Newly opened accounts	Reported where income arises	FBAR and Form 8938 where thresholds are met

Three interactions deserve attention, none of which appears on either form in isolation:

• Refund meets credit. If the 2024 Form 1116 credited the £108,000 of PAYE, recovering it is a foreign tax redetermination under section 905(c): the US credit falls and additional US tax may follow. A UK refund should never be calculated alone.
• New UK tax meets old return. Tax now assessed on UK-part dividends and gains can support amended US credits, subject to the sourcing and treaty re-sourcing rules and the section 6511 limit for credit claims. The UK gain on US stock is where this needs care, and the net investment income tax may not be reduced by the same credit.
• Calendar mismatch. UK 2024-25 straddles the 2024 and 2025 Forms 1040. Income must be mapped to both, and the accrual or cash credit method followed consistently.

A FIG claim produces its own result: no UK tax on relieved income means no UK tax to credit, so the US charge is borne in full. UK accounts opened on arrival can also create the first missed FBAR, whose exposure can be gauged using our FBAR penalty calculator. Where US filings are also behind, IRS streamlined procedures may be relevant, but that eligibility should be assessed in parallel with the UK repair, since inconsistent facts between the two filings are costly.

How do you repair the year? A practitioner's sequence

1. Establish the record. Check the HMRC personal tax account and any correspondence for a UTR or notice to file, then determine the true filing date.
2. Rebuild the chronology. Passport stamps, flight data, lease start and keys, sale completion of the US home, payroll start, and work calendars for the hours test.
3. Test residence first, cases second. Confirm the SRT result for the year and the prior year, then test all of Cases 4 to 8, as RDR3 requires, not just the obvious one. Consider next-year conditions, including Case 8.
4. Attribute bonus and share income. Get plan documents and employer confirmation before asserting a repayment.
5. Cut brokerage statements by date. Use the UK part start date, convert to sterling and keep the workings.
6. Choose the claims the year permits. Compare arising, remittance basis (before April 2025) or FIG (from April 2025) against the US result, with both countries modelled together.
7. File, then amend. Register, file with SA109 and supporting detail, then correct Form 1116 and the 1040 for any UK movement, followed by later UK years that assumed the wrong position.

For larger balance sheets, our high-net-worth team usually assembles the two-country file first, so that the HMRC and IRS positions are consistent on the day of submission. This work is return preparation and compliance catch-up, not investment or wealth advice.

A confidential review of your arrival year

If you moved to London, assumed PAYE had dealt with the year and have since seen a US brokerage statement that gives you pause, the position is rarely as bad as it first appears, and it is often partly a refund. The dates above do run, though. Please contact our cross-border team for a confidential consultation; we will establish your notice position, test each arrival case and prepare the UK and US returns together.