Split Year Treatment UK: The Eight Cases and Who Qualifies

Split year treatment UK rules let HMRC divide one tax year into an overseas part and a UK part when you arrive in or leave the UK part way through the year, so that you pay UK tax on foreign income only for the part when you were living here. It sounds like a concession. It is really a set of eight narrowly defined cases, each with its own conditions and day limits, and if you fit one of them the treatment applies whether you want it or not.

This guide walks through why the rule exists, the three cases for leaving the UK, the five cases for arriving, the priority rules when more than one case fits, how to report it on the SA109 pages of your Self Assessment return, and the extra step Americans need because the US tax year does not split.

Why does the UK tax year need to be split at all?

The Statutory Residence Test decides your status for a whole tax year, 6 April to 5 April. HMRC's manual puts it directly: an individual "is either UK resident or non-UK resident for a full tax year, and at all times in that tax year". Without a further rule, someone who lands at Heathrow on 1 March and becomes resident for that year would owe UK tax on eleven months of income earned before they arrived.

Split year treatment is that further rule. Where the conditions of a case are met, the year is split into an overseas part, taxed as if you were non-resident, and a UK part, taxed as a resident. Foreign income arising in the overseas part is left out of the UK return. UK-source income, such as rent from a UK property, stays taxable throughout, because non-residents are taxed on UK income anyway.

Two threshold points before the cases. First, split year treatment can only apply in a year in which you are UK resident under the Statutory Residence Test. If you are non-resident for the whole year there is nothing to split. Second, GOV.UK is blunt about short absences: "You will not get split-year treatment if you live abroad for less than a full tax year before returning to the UK."

Leaving the UK: Cases 1 to 3

The departure cases share two conditions: you must have been UK resident for the previous tax year, and you must be non-UK resident for the following tax year. Each then adds its own test for what happened in the year of departure.

Case 1: starting full-time work overseas

You leave to work full time abroad and you will meet the third automatic overseas test in the following year. From the first day in the tax year on which you do more than three hours of work overseas until 5 April (the "relevant period"), you must satisfy the overseas work criteria, which include staying within a permitted number of UK workdays and UK days. Those limits shrink the later in the year you leave. HMRC's table at RFIG21070 allows, for example, up to 30 UK workdays and 90 UK days if the overseas part starts in April, 17 and 52 if it starts in September, and 7 and 22 if it starts in January.

Case 2: the partner of someone starting full-time work overseas

You move abroad to live with a partner whose circumstances fall within Case 1 for this year or the previous one, having lived together in the UK in one of those years. From your deemed departure day you must either have no UK home or, if you keep homes in both countries, spend more time in the overseas home, and you must stay within the permitted limit of UK days.

Case 3: ceasing to have a home in the UK

This is the case for people who leave without a full-time job to go to. You must "cease to have any home in the UK for the rest of the tax year", spend fewer than 16 days in the UK after that point, and within six months establish a sufficient link with another country by doing one of three things: becoming tax resident there, being present there at the end of each day for six months, or having your only home (or all your homes) there.

Arriving in the UK: Cases 4 to 8

The arrival cases all require you to have been non-UK resident for the previous tax year. Several also require you to fail the sufficient ties test for the overseas part of the year, judged against reduced day counts that scale with how late in the year the UK part begins. HMRC's table at RFIG21150 shows how sharply they shrink: if your UK part starts in September, the normal 15, 45, 90 and 120-day thresholds become 7, 22, 45 and 60.

Case 4: starting to have a home in the UK only

At the start of the year you do not meet the "only home test", meaning your only home, or all your homes, are in the UK. At some point in the year you do meet it and continue to until 5 April. You must not meet the sufficient ties test for the part of the year before that date, using the reduced limits.

Case 5: starting full-time work in the UK

You start to work full time in the UK and meet the third automatic UK test over a 365-day period, and you did not meet the sufficient ties test for the part of the year before the point at which you first met that test.

Case 6: ceasing full-time work overseas

This is the return-home case. You were non-resident for the previous year because you met the third automatic overseas test (full-time work abroad), you were UK resident in at least one of the four tax years before that, you will be UK resident in the following tax year, and you satisfy the overseas work criteria for the relevant period. The five-year look-back means Case 6 is for returning Brits and long-term residents, not first-time arrivers.

Case 7: the partner of someone ceasing full-time work overseas

You move to the UK on a day in the tax year to continue living with a partner whose circumstances fall within Case 6, you will be resident in the following year, and before your deemed arrival day you either had no UK home or spent the greater part of your time in the overseas home, within the permitted UK day limits.

Case 8: starting to have a home in the UK

You have no UK home at the start of the year, you start to have one during the year and keep it for the rest of that year and all of the following tax year, you are UK resident for the following year (and that year is not itself a split year), and you did not have sufficient UK ties in the period before the home was acquired. Case 8 differs from Case 4 in that you may keep a home abroad; what matters is acquiring and keeping a UK one.

The eight cases at a glance

Case	Direction	Trigger	Key extra condition
1	Leaving	Start full-time work overseas	Within permitted UK workdays and UK days for the rest of the year; non-resident next year
2	Leaving	Join a partner who meets Case 1	No UK home, or more time in overseas home; UK day limit
3	Leaving	Cease to have any UK home	Fewer than 16 UK days after; link to new country within 6 months
4	Arriving	Start to have your only home in the UK	Fail sufficient ties (reduced limits) before the split date
5	Arriving	Start full-time work in the UK	Meet third automatic UK test; fail sufficient ties before
6	Arriving	Stop full-time work overseas and return	UK resident in 1 of the 4 years before departure; resident next year
7	Arriving	Join a partner who meets Case 6	Resident next year; no UK home or mostly abroad before arrival
8	Arriving	Start to have a UK home	Keep it for the rest of this year and all of next; resident next year

What if more than one case applies?

It is common for an arriver to fit two cases, for instance starting a UK job (Case 5) a month after buying a UK home (Case 8). HMRC's priority rules at RFIG21030 settle it:

• Departure year: Case 1 has priority over Cases 2 and 3, and Case 2 has priority over Case 3.
• Arrival year, Cases 6 and 5 both met: the case with the earliest split date applies, otherwise Case 6.
• Arrival year, Cases 7 and 5 both met (but not 6): the case with the earliest split date, otherwise Case 7.
• Arrival year, two or more of Cases 4, 5 and 8: the case with the earliest split date.

The split date matters because it fixes how much of the year is "overseas". An earlier split date for an arriver means a shorter overseas part and more income inside the UK net, so the priority rule can cost real money. It is worth checking the dates of each trigger event before assuming the most convenient case applies.

How do you claim split year treatment on your tax return?

Although the treatment applies automatically in law, HMRC only learns about it from your return. The SA109 "Residence, remittance basis etc." supplementary pages are where it goes, and the 2025 to 2026 notes set out the mechanics:

1. Do not put an X in box 1 (non-resident). Split year treatment is only due if you are resident for the year.
2. Put an X in box 3 to say your circumstances meet the criteria for split year treatment.
3. Enter in box 6 the date from which the UK part of the year begins or ends.
4. State which case applies in the "Any other information" box, box 54. If you think more than one case applies, also tick box 3.1 and explain.
5. In box 10, enter only the days spent in the UK during the overseas part of the year. Cases 4 and 8 also need the number of UK ties in the overseas part in box 12; Cases 1 and 6 need UK workdays in the overseas part in box 13.

If you have not filed before, you will need a Unique Taxpayer Reference first, and the registration deadline for a new Self Assessment record is 5 October after the end of the tax year. Our guides on whether you need to file and registering by 5 October cover that step.

The US complication: only one side of the year splits

For an American moving to the UK, or a US citizen leaving it, split year treatment fixes the UK position but leaves the US position untouched. The US taxes citizens and green card holders on worldwide income for the calendar year, wherever they live, and there is no US equivalent of a split year for citizens. Three consequences follow.

• Different income lands in different years. Salary earned in the overseas part of a UK split year is outside the UK return but fully inside the US return for that calendar year. The reverse happens on departure.
• Foreign tax credits have to be matched. UK tax on the UK part of the year is what is available for credit on Form 1116, and the UK tax year straddles two US years. The allocation needs to be done deliberately, not by copying the P60 figure.
• Relief choices interact. A new arriver who qualifies for the UK's four-year Foreign Income and Gains regime can claim relief on foreign income in the UK part of the year, but the claim is made on the same SA109 pages and removes the personal allowance for that year. Whether it is worth it depends on how much US tax you are already paying on that income.

Our moving abroad tax checklist sets out the sequence for a US-UK move, and the moving abroad service handles both returns together so the split date, the credits and any FIG claim are decided once.

Illustrative example: a US citizen moves from New York to London and starts a full-time UK job on 1 September 2026, having had no UK home or UK ties before that. She meets Case 5, so 6 April to 31 August 2026 is her overseas part and her US salary for those months stays out of the UK return. Her US return for calendar 2026 still reports all twelve months of salary. UK tax paid on September to December 2026 earnings is claimed as a credit on her 2026 Form 1116, and UK tax on January to April 2027 earnings is claimed on the 2027 form. This is illustrative only; the right answer depends on the actual dates and facts.

Where people get split year treatment wrong

• Assuming a short posting qualifies. The departure cases need non-residence in the following tax year, so a nine-month secondment that ends in the next tax year usually fails.
• Forgetting the day limits shrink. The permitted UK days for Case 1 and the reduced ties thresholds for Cases 4, 5 and 8 are scaled to the month of the split. A few extra UK trips late in the year can break the case.
• Keeping a UK home in a Case 3 departure. Case 3 requires having no UK home for the rest of the year. Renting your house out on a proper tenancy is different from leaving it available for your use.
• Filing without the SA109 pages. Ticking nothing means HMRC taxes you as resident for the whole year. The split has to be reported.
• Reconciling only one return. Americans need the UK split date carried into the Form 1116 allocation, or credits are lost or double counted.

The bottom line

Split year treatment is a rules-based test, not a discretionary relief. Identify which of the eight cases fits your move, check the day limits and the following-year condition, work out the split date under the priority rules, and report it on the SA109 pages. If you are also filing in the US, treat the split date as an input to the American return rather than a UK-only detail. Getting the date right once is far cheaper than amending two years of returns in two countries.