How do tax residency, domicile and a residence permit differ?

	Residence permit	Tax residency	Domicile
Decided by	Immigration authority	Tax authority	Courts / general law
Turns on	A grant you applied for	Days present and ties	Where your permanent home is
Governs	Entry and stay	What income is taxed	Inheritance and succession
Changes	When granted or revoked	Year by year, automatically	Rarely, and hard to shed

This is the confusion that costs money in both directions. You can hold a residence permit and not be tax resident, because you are rarely in the country; you can be squarely tax resident with no permit at all, because day counts and ties do not ask about your immigration paperwork.

The US is the exception that makes the rule memorable. Under the green card test, a lawful permanent resident is a US tax resident from the day the status is granted, with no day counting involved — and it continues while you live abroad until the status is formally abandoned or revoked. There, the immigration document is the tax trigger; see what keeping a green card requires.

Domicile is the oldest of the three and the least intuitive: you acquire a domicile of origin at birth, and you only replace it with a domicile of choice by both living somewhere else and intending to stay there indefinitely. Leaving is not enough. That is why people who moved decades ago remained UK-domiciled.

From 6 April 2025 the UK stopped using it. Domicile and deemed domicile were replaced by a long-term UK resident test: you are long-term resident if you have been UK tax resident for 10 of the previous 20 years, which puts your worldwide assets within inheritance tax. The connection also has a tail — leaving does not end it immediately, and someone with 10 to 13 years of residence stays long-term resident for 3 years after departure, rising with longer residence. Whether you meet it is now answered by the Statutory Residence Test, year by year.

The word is a false friend, and the trap is quiet. In France, domicile fiscal is simply the term for tax residence; Italy's domicilio likewise sits inside its residence test rather than beside it. Neither carries the common-law baggage above.

US states use a third meaning again: domicile as the state you intend to return to, which is how a state keeps taxing someone who has already moved — the mechanism behind whether you still owe tax to the state you left.

So read "domicile" in context. The same word means a sticky common-law status in one place, an ordinary residence test in another, and a state's claim on you in a third.

• HMRC — RDRM22010: the three categories of domicile
• GOV.UK — Inheritance Tax if you're a long-term UK resident
• IRS — Alien residency: the green card test
• HMRC — RDR3: Statutory Residence Test