The UK statutory residence test, step by step.

The UK test still works the same way, but the treaty tie-breaker with each other country becomes relevant to where you are finally treated as resident.

Multi-country patterns are exactly where a mechanical checker stops being sufficient.

Treat it as a starting point. If it says an obligation applies, the next question is what the filing actually involves and whether earlier years are affected.

If it says nothing applies, it is worth re-running whenever your circumstances change - a move, a property, a new account.

It runs in a fixed order: automatic overseas tests first, then automatic UK tests, then the sufficient-ties test if neither has settled it.

Because it is mechanical rather than a judgement call, your position can be worked out in advance.

Family, accommodation, work, days spent in the UK previously, and whether the UK is where you spend most time. The number you need depends on your day count and history.

They are factual, so keeping a contemporaneous record is far stronger than reconstructing later.

It covers the common cases and will tell you reliably whether the basics apply to you. It is a guide, not a filing position.

Edge cases - trusts, business ownership, unusual residence patterns - can change the answer, which is why the result flags when a position is worth checking properly.