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The short answer
If you leave the UK for Nigeria part-way through a tax year, split year treatment can divide that year so you are taxed as UK resident only up to your departure. There are three leaving cases: Case 1 if you start full-time work overseas, Case 2 if your partner does and you go with them, and Case 3 if you stop having a UK home. Each needs you to be UK resident in the year before and non-resident in the year after.
Without split year treatment, a person who is UK resident for a tax year is taxed on their worldwide income for the whole year, from 6 April to 5 April. For someone moving to Lagos in October, that would mean the UK taxing Nigerian salary for the last six months. Split year treatment is how the UK avoids that, but it is not automatic: you have to fit one of the cases.
First, are you UK resident for the year?
Split year treatment only applies if you are UK resident for the tax year under the Statutory Residence Test. If you are non-resident for the whole year, for example because you meet an automatic overseas test, the question does not arise. HMRC's RDR3 guidance sets out the tests; one automatic overseas test is full-time work abroad with fewer than 91 UK days and fewer than 31 days working more than three hours in the UK. For the full test, see the Statutory Residence Test for Nigerians.
The three leaving cases
LITRG's guide (updated 6 April 2026) describes them in order of priority. Case 2 applies only if Case 1 does not; Case 3 applies only if neither does.
| Case | Who it fits | Where the split falls | Key conditions |
|---|---|---|---|
| Case 1 | You start full-time work overseas | The day the overseas work starts | UK resident in the previous year; non-resident the next year because of full-time work abroad; meet the full-time work conditions from start of work to year end, with day limits apportioned |
| Case 2 | Your partner falls within Case 1 and you go too | The later of the day you join them to live overseas and the start of their overseas part | UK resident previous year, non-resident next year; further conditions in HMRC's manual |
| Case 3 | You stop having a UK home | The day you cease to have a UK home | No more than 15 UK days in the overseas part; within six months, tax resident in the new country, or present there every day, or your only home(s) there; UK resident previous year, non-resident next year |
LITRG warns that the rules should be worked through in detail as they can give an unexpected result. A common surprise is Case 1's apportioned day limit: a shorter overseas part of the year means fewer permitted UK days.
Example (illustrative)
Example: Kemi has lived and worked in Birmingham for eight years. She accepts a full-time job in Lagos starting 1 November 2026, leaves the UK on 25 October, and expects to stay in Nigeria for at least two years. Case 1 could apply, with the UK part of 2026-27 ending on 31 October and the overseas part starting 1 November. Her husband, who resigns and joins her on 10 December, could look at Case 2 from 10 December. If Kemi instead had moved without a job, selling her UK flat on 30 September, Case 3 could split the year from 30 September, provided she spent no more than 15 days in the UK afterwards and met the six-month test in Nigeria.
Reporting the split
HMRC's SA109 notes for 2026 say split year treatment is claimed on the residence pages of the Self Assessment return: tick that you were UK resident, state the case that applies and give the date the split starts. Keep evidence of the date: an employment contract and start date for Case 1, completion statements or a tenancy end for Case 3.
The P85 for employees
If you were employed and do not file Self Assessment for the year you leave, GOV.UK's P85 guidance applies. The form is for people who lived and worked in the UK and want to claim back tax; you need your P45, and the form asks about your UK home, full-time work abroad and how much time you expect to spend in the UK over the next three years. If you have not yet left, you must print the form and post it rather than use the online version. GOV.UK says refunds are paid into a bank account in your or a nominee's name, and HMRC does not cover conversion or overseas fees, so keeping a UK account open is sensible. If you are filing Self Assessment for the year, you do not need the P85. See the P85 when returning to Nigeria.
Gains and later returns
HMRC's HS278 helpsheet says CGT normally applies only to gains in the UK part of a split year, and that leavers are generally not charged on gains in the years after leaving, apart from UK land and some business assets. But if you come back within five years, gains made while away can be taxed on return; read temporary non-residence before selling anything large. On the Nigerian side, residence can start as soon as you have a home there; see when Nigerian tax starts.
Questions people ask
Can I be non-resident in the UK from the day I leave for Nigeria?
Yes, if split year treatment applies. The year is divided into a UK part and an overseas part from the date set by the case you meet.
What is split year Case 1?
It applies when you leave to start full-time work overseas and are non-resident the next tax year because of it. The split is from the day the overseas work starts.
How many days can I spend in the UK after leaving under Case 3?
No more than 15 days in the overseas part of the year, per LITRG's description of Case 3.
Do I need a P85 if I file Self Assessment?
No. GOV.UK says the P85 is not needed if you are filing a Self Assessment return for the year you leave.
Sources
- LITRG: Split year treatment, leaving the UK (updated 6 Apr 2026) · accessed Oct 2026
- HMRC RDR3: Statutory Residence Test guidance note (updated 11 Jun 2026) · accessed Oct 2026
- GOV.UK: Get your Income Tax right if you're leaving the UK (P85) · accessed Oct 2026
- HMRC HS278: Temporary non-residents and Capital Gains Tax (2026) · accessed Oct 2026
This article is general information, not financial, legal or tax advice. Products described are provided under the terms on this site and are subject to regulation and eligibility.