Arguing one is domiciled in one of the nations of the UK can have very bad consequences for UK IHT and income tax purposes. A dual US/UK perspective needs to be taken of this question.
I just posted a lengthy explanation in another thread, entitled "Dual citizenship and UK taxes", on why this is not necessarily so, linking to the leading US state case on the issue, taught to every US law student who studies Conflict of Laws:
http://www.uniset.ca/other/css/182NW227.htmlI am not an accountant but a tax lawyer, and this is the point: domicile not only has different meanings under English/Scottish/NI law from what it has under US state law, but at least in the USA it does not have a single meaning for different purposes:
Does Domicil Bear a Single Meaning? (a 1955 article by the rapporteur of the Second Restatement, Conflict of Laws).
Putting aside the not unimportant question of whether a UK tax inspector might be ignorant of all this and use the assertion against you (unlikely in my experience once the definitional difference is explained), status for the purpose of the tax laws of a US state has nothing to do with status in the United Kingdom. Wait, there's more: US states are not bound by federal tax treaties with foreign countries.
I have a daughter who has never iived in the USA and yet, under English law, she is almost certainly domiciled for purposes of English law in New York State, a place I have not lived in since the early 1970s. And under New York law I am domiciled either in Florida or in England; probably the latter for most purposes.
When it is said that "one can only have a single domicile" that is wrong: both domestically (US) as Professor Reese proved, and internationally (because, treaty tiebreaker rules aside, domicile is simply defined differently in the USA on the one hand, and other Common-Law systems on the other. And still differently in Civil-Law countries (Louisiana, and less relevantly Florida, both have a facility for registration of domicile the way many or most Civil-Law countries do -- but they are optional).
Here's a domestic US state-tax example of the issue, interesting because it involved a former director of the Maryland state tax board:
http://www.loislaw.com/advsrny/doclink.htp?alias=MDCASE&cite=397+A.2d+1009So: it is true that conceding acquisition of domicile of choice in England, Scotland or N.I. can have disastrous consequences for IHT and unremitted income (with just perhaps a workaround via hybrid entities deemed corporations in one country and partnerships in another, if the IR35 issue can be finessed). But claiming to have left one US state for good (or "indefinitely), preferably in favour of another US state or territory prior to moving to the UK, has little or no impact on one's domicile status here.
Becoming naturalised in the UK establishes one further "badge" of domicile that a UK tax inspector could use. But, independent spousal domicile notwithstanding (Domicile and Matrimonial Proceedings Act 1973) UK tax inspectors operate on the basis of a rebuttable assumption that spouses do share a domicile, and have told me that they do not (unless contrary facts come to their attention) seek to impose IHT on the estates of spouses who arguably have separate domiciles (one UK and one foreign).
For long-term residents of the UK other than diplomats and visiting forces (both of which, at least in the case of the US, have a 5-year assignment limit anyway) the issue is mooted by the "deemed domicile" rules (17 out of 20 years for IHT, 7 out of 9 for remittance basis).
But you knew all that already.
Sorry for intervening; I thought it was useful to put all that on the record and now I'll go away.
