The UK Statutory Residence Test (SRT) explained: ties, days, and automatic tests
The UK SRT is a complex three-stage test: automatic non-resident tests, automatic resident tests, then a sufficient-ties test. Here's how to count days, ties, and what triggers UK tax residency.
The UK Statutory Residence Test (SRT) is the most complex residency test in the developed world. It has three stages: automatic non-resident tests, automatic resident tests, and a sufficient-ties test. Day counts matter at every stage, and the tax year runs 6 April to 5 April, not the calendar year.
The three stages of the SRT
HMRC applies the SRT in this order. Stop at the first one that applies:
- Stage 1, Automatic non-resident tests: if any apply, you're definitely non-resident.
- Stage 2, Automatic resident tests: if any apply (and stage 1 doesn't), you're definitely resident.
- Stage 3, Sufficient ties test: if neither stage 1 nor 2 settles it, count your UK ties and compare against your UK day count.
Stage 1: Automatic non-resident tests
You are automatically non-resident if any of these apply for the tax year:
- You spent fewer than 16 days in the UK and were UK resident in one or more of the previous 3 tax years.
- You spent fewer than 46 days in the UK and were not UK resident in any of the previous 3 tax years.
- You worked full-time overseas, spent fewer than 91 days in the UK, and worked fewer than 31 UK working days.
Stage 2: Automatic resident tests
You are automatically resident if any of these apply (and you didn't qualify under stage 1):
- You spent 183 or more days in the UK during the tax year.
- Your only home is in the UK (with various conditions on duration).
- You worked full-time in the UK for any 365-day period that overlaps the tax year.
183 is HMRC's hard line: cross it and the SRT is over, you're a UK resident, no ties analysis needed. The other tests can still catch you below 183, so day count alone isn't enough.
Stage 3: The sufficient-ties test
If neither stage settles your status, count your UK ties:
- Family tie: spouse, civil partner, or minor children resident in the UK.
- Accommodation tie: a place to live in the UK that's available for at least 91 consecutive days, used for at least one night.
- Work tie: 40 or more UK working days (3+ hours of work).
- 90-day tie: 90+ days in the UK in either of the previous 2 tax years.
- Country tie (only for 'leavers'): the UK is the country where you spent the most days.
Then check the day-and-tie matrix:
| Days in UK | Arrivers (≤3 yrs UK history) | Leavers (UK resident in any of last 3 yrs) |
|---|---|---|
| 0–15 | Always non-resident | Always non-resident |
| 16–45 | Always non-resident | Resident if 4+ ties |
| 46–90 | Resident if 4 ties | Resident if 3+ ties |
| 91–120 | Resident if 3+ ties | Resident if 2+ ties |
| 121–182 | Resident if 2+ ties | Resident if 1+ tie |
| 183+ | Always resident | Always resident |
What counts as a UK day?
A 'day' for SRT purposes is a day where you were physically present in the UK at midnight. There are exceptions:
- Transit days: if you arrive and depart on the same calendar day and don't engage in non-transit activities, the day doesn't count.
- Exceptional circumstances: illness or events beyond your control may exclude up to 60 days.
- Deeming rule (90-day tie): if you have a 90-day tie and 30+ qualifying days, additional days can count even if you weren't there at midnight. Watch out.
The deeming rule is what catches frequent flyers. If you had a 90-day tie in either of the last 2 years, days you were in the UK but not at midnight (a one-day visit) can still count toward your day total. The math is hairier than it looks.
The UK tax year (6 April – 5 April)
The UK tax year runs from 6 April to 5 April the following year. If you're tracking against the SRT, you must count days within that window, not the calendar year. This catches Americans and Europeans whose tax software defaults to calendar years.
Split-year treatment
If you arrive in or leave the UK during a tax year, you may qualify for split-year treatment, the year is split into a UK-resident part and a non-resident part for income tax. There are 8 cases (5 for arrivers, 3 for leavers), each with specific conditions on home, work, and family. This is where most people benefit from professional advice.
How to track for the SRT
Manual SRT tracking is brutal because of the deeming rule, midnight rule, and tax-year boundary. Tax Days handles all three: configure your SRT profile (arriver vs. leaver, ties), and the app counts days against the UK tax year, applies transit-day exceptions, and projects when you'd cross each tie threshold.
If you're an American or Brit moving back and forth, the SRT and the US Substantial Presence Test compete. You can be a tax resident of both countries and rely on the US/UK treaty's tie-breaker. That requires a documented day count for both jurisdictions, exactly what Tax Days produces.
Frequently asked questions
How many days in the UK make me automatically resident under the SRT?
Spending 183 or more days in the UK during the tax year makes you automatically resident, with no ties analysis needed. You can also be automatically resident below 183 days if your only home is in the UK or you work full-time in the UK, so the day count alone doesn't settle it.
What counts as a day of presence for the UK SRT?
Generally a day counts if you were physically present in the UK at midnight. Same-day transit without non-transit activities doesn't count, up to 60 days of exceptional circumstances such as illness can be excluded, and a deeming rule can count some non-midnight days for people with a 90-day tie.
What are the five UK ties in the sufficient-ties test?
The family tie (a UK-resident spouse, civil partner, or minor children), the accommodation tie (a place to live available 91+ consecutive days and used at least one night), the work tie (40 or more UK working days), the 90-day tie (90+ UK days in either of the previous two tax years), and, for leavers only, the country tie (the UK is where you spent the most days).
What is the difference between an arriver and a leaver?
A leaver was UK resident in any of the previous three tax years; an arriver was not. Leavers face stricter thresholds: for example, at 121 to 182 UK days a leaver is resident with just one tie, while an arriver needs two or more.
Does the UK SRT use the calendar year?
No. The UK tax year runs from 6 April to 5 April of the following year, so SRT day counts must be measured over that window. This regularly trips up Americans and Europeans whose tracking defaults to the calendar year.