for at least one of the four tax years ending with the relevant tax year. The start date for acquisition of 15-year deemed domicile is 6 April in the tax year after the 15/20 year test is satisfied. It does not matter whether a person is resident in that tax year. The deemed domicile under this rule ends when either of the two conditions under s.267(1)(b) set out above are not met. Formerly domiciled resident rule Section 267(1)(aa) of the Inheritance Tax Act 1984 provides: A person not domiciled in the UK at any time (in this section referred to as “the relevant time”) shall be treated for the purposes of this Act as domiciled in the UK (and not elsewhere) at the relevant time if... (aa) he is a formerly domiciled resident for the tax year in which the relevant time falls (“the relevant tax year”) “Formerly-domiciled resident” is a label for a set of four rules. Section 272 provides: “formerly domiciled resident”, in relation to a tax year, means a person— (a) who was born in the UK, (b) whose domicile of origin was in the UK, (c) who was resident in the UK for that tax year, and (d) who was resident in the UK for at least one of the two tax years immediately preceding that tax year. The domicile start date for formerly-domiciled residents under the IHT deemed domicile rule is 6 April in the 2nd year of residence. The domicile end date for formerly-domiciled residents is 6 April in the first year of non-residence. The same rule applies for income tax and capital gains tax but without the one-year grace period in condition (d). 3-year rule The 3-year rule concerns the person who is actually UK domiciled and who loses their UK domicile. The domicile start date for this rule is the date of change of domicile, and the domicile end date is 3 years after that date. Section 267(1)(a) of the Inheritance Tax Act 1984 provides: A person not domiciled in the UK at any time (in this section referred to as “the relevant time”) shall be treated for the purposes of this Act as domiciled in the UK (and not elsewhere) at the relevant time if— (a) he was domiciled in the UK within the three years immediately preceding the relevant time. United States Each state of the United States is considered