The UK Statutory Residence Test and ties, explained
The UK doesn't use a flat 183 days — your "ties" can drop the threshold to 45. How the Statutory Residence Test works, the sufficient-ties table, and tracking the days it depends on.
Short answer: the UK decides residency with the Statutory Residence Test (SRT). After the automatic tests, most travellers land in the sufficient ties test, where the number of days that makes you UK resident falls as your number of ties rises — from 183 down to as few as 45.
The sufficient-ties table (leavers)
For someone who was UK resident in a recent year ("leavers"), roughly:
| UK ties | Days that make you resident | |---|---| | 4+ ties | 16 | | 3 ties | 46 | | 2 ties | 91 | | 1 tie | 121 | | 0 ties | 183 |
(Thresholds differ slightly for "arrivers." The point stands: more ties = fewer days allowed.)
The five ties
- Family — spouse/partner or minor children UK resident.
- Accommodation — a place to live available to you in the UK.
- Work — 40+ days of UK work in the year.
- 90-day — 90+ days in the UK in either of the previous two tax years.
- Country — the UK is where you spent the most days that year (counts only for leavers).
The UK tax year runs 6 April – 5 April, and split-year treatment can apply in the year you arrive or leave.
Why ties make it slippery
Two ties quietly turns "183 days" into "91 days." If you don't know your tie count, you don't know your real limit — and the 90-day tie depends on the prior two years' day counts.
How Flags does it
Flags: Tax Residency includes a UK ties editor: toggle accommodation, family and work; it derives the 90-day and country ties from your recorded history, then shows the day threshold that actually applies to you ("2 of 5 ties · 91-day threshold"). Days come from your photos, on-device.
Flags' UK ties model is simplified and is not tax advice — it doesn't fully quantify every SRT condition or split-year nuance. Confirm with a qualified UK adviser.