Most people do not leave or return to the UK neatly on 6 April. They start a new job overseas in September, sell the family home in the spring, or come back for a role in the UK halfway through the year. That raises an obvious question: how is the tax year you move taxed?
The answer often lies in split year treatment. In a tax year when you are UK resident, split year treatment can divide that year into a UK part and an overseas part. The UK part is taxed as a UK resident. The overseas part is, for most purposes, taxed as if you were non-resident.
It is not something you choose or opt into. If your circumstances meet one of the cases set out by HMRC, split year treatment applies. If they do not, you are treated as UK resident for the whole year, even if you spent most of it abroad.
That is why it pays to understand the rules before you move, not after the tax year has ended.
Split year treatment only applies if you are UK resident for the year
Split year treatment does not decide whether you are UK resident. That question comes first, and it is answered by the Statutory Residence Test.
If the test shows you are non-resident for the whole tax year, split year treatment is not needed. It only becomes relevant when you are UK resident for the year but your circumstances changed partway through, because you left the UK or arrived here.
So the order is always the same. Work out your residence status for the year first, then check whether one of the split year cases applies.
The three cases for leaving the UK
HMRC sets out three cases for people leaving the UK in its split year treatment guidance. Each one also requires you to have been UK resident in the previous tax year and to be non-resident in the following tax year.
Case 1: Starting full-time work overseas. This is the case most relevant to Britons taking up overseas employment. You need to be non-resident in the following tax year under the Full Time Work Overseas Test, so your working hours, UK workdays and time spent in the UK all matter.
Case 2: The partner of someone starting full-time work overseas. This can apply if you move abroad to join a spouse, civil partner or partner who is starting full-time work overseas.
Case 3: Ceasing to have a home in the UK. This can apply if you stop having any home in the UK partway through the year. From that point, you must spend fewer than 16 days in the UK and, within six months, become tax resident in another country, be living there, or have your home there.
Each case has its own conditions, and small details can decide whether you qualify. If you are planning a move, our guide to the tax steps to take before leaving the UK covers what to sort out before you go.
The five cases for arriving in or returning to the UK
There are five cases for people coming to the UK or coming back after a period abroad. Each one requires you to have been non-resident in the previous tax year, and some also look at your position in the following year.
Case 4: Starting to have a home in the UK only. This can apply where your only home becomes a home in the UK.
Case 5: Starting full-time work in the UK. This applies where you start full-time work in the UK partway through the year.
Case 6: Ceasing full-time work overseas. This is often relevant to Britons returning after an overseas contract ends. It applies where you were non-resident the year before because you were working full-time abroad, and you are UK resident again the following year.
Case 7: The partner of someone ceasing full-time work overseas. This applies if you return to the UK with a spouse, civil partner or partner whose overseas work has ended.
Case 8: Starting to have a home in the UK. This can apply where you start to have a home in the UK partway through the year.
Returning Britons often assume the year they come back will simply be split at their arrival date. That is not always the case, which is why the specific conditions matter.
What happens if more than one case applies?
It is possible to meet the conditions of more than one case in the same year. HMRC sets an order of priority so that only one case decides where the year is split.
For people leaving the UK, Case 1 takes priority over Cases 2 and 3, and Case 2 takes priority over Case 3. For people arriving, the order depends on which case gives the earliest split year date.
The case that applies can change the date the overseas part of the year begins or ends. That date affects which income is taxed in the UK.
Coming back within five years: temporary non-residence
If you return to the UK after a short time abroad, there is another set of rules to be aware of. HMRC’s temporary non-residence rules can apply where your period of non-residence lasts five years or less, and you were UK resident in at least four of the seven tax years before you left.
Where these rules apply, certain income and gains from your time abroad can become taxable in the UK when you return. This catches some people out, because they assume that anything received while they were non-resident is permanently outside UK tax.
If you are planning a short overseas assignment, or thinking about coming home sooner than expected, it is worth checking how these rules could affect you. HMRC explains the rules in its Statutory Residence Test guidance.
Common split year mistakes
Split year treatment can look simple when you read about it at a high level. The difficulty is applying it to real life, where moves rarely happen on a single clean date. Some of the most common mistakes we see include:
- assuming the tax year automatically splits on the day you fly out or arrive
- treating split year treatment as something you can choose to claim
- forgetting that it only applies if you are UK resident for the year
- not checking which case applies when more than one could
- returning to the UK regularly without tracking UK workdays and days spent here
- keeping a UK home available without considering how it affects the leaving cases
- relying on rough estimates rather than accurate travel records
Any one of these can change the date your overseas part begins or ends, or mean split year treatment does not apply at all.
Good records matter more than people expect
If your position depends on when you left, when you started work overseas or when you came back, you need to be able to support it properly.
In many cases, that means keeping clear and consistent evidence of where you were, when you travelled, where you carried out your work and when your home situation changed. Employment contracts, travel records, tenancy or sale documents and payslips can all help.
Trying to reconstruct that later can be difficult, especially if HMRC asks questions after the event.
Not sure whether split year treatment applies to you?
The year you leave or return to the UK is often the most complicated tax year you will have. The dates, your working pattern and what happens to your UK home can all affect the outcome.
Our team of former HMRC officers can review your circumstances, confirm your residence position and explain how your tax year is likely to be treated. Find out more about our non residence tax advice, or speak to us before you file.
Need help with your tax situation? Get Advice on Your Tax Year