There is no single day count that tells you whether you are UK tax resident - and that surprises a lot of people. Since 6 April 2013, the UK Statutory Residence Test (SRT) has decided your residence for each tax year through a fixed sequence of tests, and the number of days you can safely spend in Britain slides anywhere between about 16 and 183 depending on your ties and your history. This guide walks through the SRT in the order HMRC applies it, explains how a UK day is counted, and shows how to keep an accurate, provable UK day total on your phone.
What the UK Statutory Residence Test decides
The SRT is a statutory framework that replaced decades of vaguer case law. For every UK tax year - which runs 6 April to 5 April, not 1 January to 31 December - it gives a yes-or-no answer to one question: were you UK tax resident for that year? Residence matters because a UK resident is generally taxable on worldwide income and gains, while a non-resident is taxed only on UK-source income.
That distinction matters more than it used to. From 6 April 2025 the old non-domicile regime was abolished, and domicile no longer shields your foreign income and gains from UK tax. Residence itself is now the pivot: a new residence-based Foreign Income and Gains (FIG) regime gives arrivals who were non-UK-resident for the previous 10 tax years up to 4 years of relief on foreign income and gains, after which worldwide taxation applies. None of this changes how the SRT counts your days, but it makes getting your residence status right more consequential than ever.
Crucially, the SRT is applied in a fixed order. You work through three stages and stop at the first that gives a definitive answer:
- The automatic overseas tests - pass any one and you are non-resident, full stop.
- The automatic UK tests - if no overseas test applied, pass any one of these and you are resident.
- The sufficient-ties test - only reached if the first two stages were inconclusive.
Stage 1: the automatic overseas tests
HMRC looks at these first because they let genuinely departed or full-time-overseas taxpayers settle their status quickly. Meet any one and you are non-resident for the year, regardless of anything in the later stages:
- You were UK resident in one or more of the previous three tax years and spend fewer than 16 days in the UK this year.
- You were not UK resident in any of the previous three tax years and spend fewer than 46 days in the UK this year.
- You work full-time overseas across the year, with only a limited number of UK days and a limited number of UK working days.
Notice how much your recent history matters: a "leaver" who was resident last year has a much tighter 16-day allowance than a newcomer's 46 days. This is why the same trip can be safe for one person and costly for another.
Stage 2: the automatic UK tests
If no overseas test settled the matter, HMRC moves on. Meet any one of the automatic UK tests and you are resident for the year:
- You are present in the UK for 183 days or more in the tax year.
- Your only home is in the UK for a sufficient part of the year (broadly, you have no home overseas, or spend little time there).
- You work full-time in the UK over a 365-day period that falls within the year.
The 183-day line is the one most people have heard of, but for anyone with real ties to Britain it is rarely the binding number. That is what the third stage is for.
Stage 3: the sufficient-ties test, where days and ties trade off
When neither automatic stage is decisive, the outcome turns on how many UK ties you have. The more ties, the fewer days you can spend before you tip into residence. The recognised ties are:
- Family tie - a spouse, civil partner or minor child who is UK resident.
- Accommodation tie - a place available to live in the UK that you use during the year.
- Work tie - you do a meaningful amount of work in the UK during the year.
- 90-day tie - you spent 90 or more days in the UK in either of the previous two tax years.
- Country tie - for "leavers" only: you were present in the UK at midnight on more days than in any other single country.
The test then combines your tie count with your recent history to produce a day threshold. Broadly, a leaver with all the ties can become resident at a threshold near the bottom of the range, while an arriver with few ties keeps an allowance closer to the top. That is why UK thresholds effectively slide between roughly 16 and 183 days - there is no one number that fits everyone.
How a UK day is counted
The SRT counts a day if you are in the UK at midnight at the end of that day - the "midnight rule". This is stricter to your advantage than the "any part of a day" rule many countries use: a day trip that ends before midnight generally does not add to your count.
- Arrive in the morning and stay overnight, and that day counts.
- Fly in for a lunchtime meeting and leave the same evening, and that day usually does not count.
- There is a limited deeming rule that can count some days even without a midnight presence once you have many UK ties and a lot of UK days, and transit-day exceptions for passengers simply passing through between two non-UK points.
Because the threshold you are measured against can be as low as 16 days, a handful of miscounted midnights is the difference between resident and non-resident. Precision here is not optional. See how to count days for tax residency for how the midnight rule compares with other methods.
Tracking your UK days in the app
With thresholds that slide and a day rule pinned to midnight, the UK is exactly the kind of test that rewards continuous, automatic tracking. Tax Residency Tracker keeps your UK count accurate in the background:
- Set the tax year to 6 April using customizable tax-year periods, so your UK count starts and ends on the SRT's dates instead of a generic 1 January.
- Use the Midnight Rule counting mode, which matches the SRT exactly, so a UK day is counted only where you are at midnight and day trips do not inflate your total.
- Automatic GPS day detection spots border crossings and creates a dated stay for each country, even when the app is closed, so no UK midnight goes unrecorded.
- A real-time UK day total shows exactly how many days you have accrued against the threshold you are aiming to stay under, and threshold alert notifications warn you before you cross a custom UK day limit you have set.
- Planned-stay previews let you add a future UK trip and see whether it pushes you over your line before you book it.
- CSV export with proof documents hands your accountant a dated, evidenced record of every UK day if HMRC ever asks you to substantiate it.
Everything is processed on your device, works fully offline, and is never uploaded, so your travel history stays private while remaining audit-ready.
Frequently asked questions
How many days can I spend in the UK without becoming resident?
It depends entirely on your ties and recent history. A recent "leaver" with several UK ties can become resident at as few as 16 days, while someone with no ties who was not resident in the previous three years can spend up to 45 days and still pass an automatic overseas test. The 183-day figure only settles residence for people the earlier stages did not resolve.
Does the UK count arrival and departure days?
The SRT uses the midnight rule, so a day counts only if you are in the UK at midnight at the end of it. That means an arrival day where you stay overnight counts, but a departure day where you leave before midnight generally does not, subject to the limited deeming rule and transit-day exceptions.
When does the UK tax year start?
The UK tax year runs from 6 April to 5 April. All SRT day counts are measured over that period, which is why you should set your app's tax-year start to 6 April rather than 1 January.
What are the UK ties for the sufficient-ties test?
Family, available accommodation, work in the UK, a 90-day tie (90+ UK days in either of the previous two years) and, for leavers only, a country tie (more days in the UK than in any other single country). The more ties you have, the fewer days you can spend before becoming resident.
Did the 2025 non-dom changes affect the SRT?
No. The abolition of the non-domicile regime and the new residence-based Foreign Income and Gains (FIG) regime from 6 April 2025 sit on top of residence; they do not change how the SRT counts your days or defines its tests. What changed is the stakes: with domicile no longer shielding foreign income and gains, being UK resident now pulls worldwide income into scope sooner, so counting your UK days accurately matters more.
Next, see how the 183-day rule works across countries, how to count days for tax residency, tax residency for digital nomads, or browse all tax-residency guides.