When you leave the UK, the single biggest factor in your tax bill is whether HMRC still treats you as a UK tax resident. Residents are taxed on their worldwide income; non-residents are generally taxed only on UK-source income. The answer comes from the Statutory Residence Test (SRT) — the framework introduced in 2013 that replaced decades of vague case law.
This guide walks through how the test works, the day-count thresholds that catch most expats, and what to check before you go.
The three parts of the test, in order
The SRT runs through three stages. As soon as one gives a definitive answer, you stop — you don't move on to the next.
- The automatic overseas tests. Meet any one of these and you are non-resident, full stop. The most common for leavers: you spend fewer than 16 days in the UK in the tax year, or you work full-time overseas with limited UK workdays and fewer than 91 UK days.
- The automatic UK tests. If no overseas test applies, these can make you automatically resident — for example, spending 183 or more days in the UK, or having your only home in the UK.
- The sufficient ties test. If neither set settles it, your residence depends on how many days you spend in the UK combined with how many "ties" you keep here.
The day-count thresholds that catch expats
Most people who have genuinely left are decided by the ties test. The number of UK days you can spend before becoming resident falls sharply as you keep more ties (these are the thresholds for "leavers" — people who were UK resident in one or more of the previous three tax years):
| UK ties | Days before you're UK resident |
|---|---|
| 4 or more ties | 16 days |
| 3 ties | 46 days |
| 2 ties | 91 days |
| 1 tie | 121 days |
| 0 ties | 183 days |
A "day" in the UK generally means being here at midnight. Keep a careful count from the day you leave — the thresholds are unforgiving and a handful of extra visits home can flip your status for the whole year.
What counts as a "tie"?
There are five possible ties. Leavers can have all five; arrivers ignore the country tie:
- Family tie — a spouse, civil partner or minor child resident in the UK.
- Accommodation tie — a place to live available to you in the UK for a continuous period, and used during the year.
- Work tie — 40 or more days doing more than three hours of work in the UK.
- 90-day tie — 90 or more days in the UK in either of the previous two tax years.
- Country tie — the UK is the country where you spent the most midnights (leavers only).
Split-year treatment
The tax year isn't always all-or-nothing. If you leave (or arrive) partway through, split-year treatment can divide the year into a UK part and an overseas part, so you're only taxed as a resident for the portion before you left. There are strict cases that must be met — it isn't automatic.
Check your own position
The SRT rewards planning: the difference between 2 ties and 3 ties, or leaving on the right side of a day threshold, can decide whether a whole year of foreign income is taxable in the UK. Run your own numbers with our free Statutory Residence Test calculator, and keep a running tally with the UK Days Abroad counter so you never accidentally cross a threshold.