Long-Term UK Residence Test HMRC Form Updated as Domicile Rulings Bite

Two rulings handed down days apart show how claims about domicile can unravel once a court starts asking questions. The First-tier Tribunal decided on 12 October 2026 that Sir John Griffin, founder of Addison Lee, owes £20.5 million in additional UK tax, after Judge Michaela Snelders concluded he had been domiciled in England all along, not Ireland as he had long argued. The same week, Jersey's Royal Court unwound a £17.3 million trust, finding that the domicile advice underpinning it was, in the court's own words, "simply wrong".

Strictly speaking, neither case touches the rules that now govern inheritance tax on offshore bonds and trusts. Since 6 April 2025, that question has turned on residence rather than domicile: under section 6A of the Inheritance Tax Act 1984, anyone who has been UK resident for at least 10 of the previous 20 tax years counts as a long-term UK resident, as PPLI.com has set out. HMRC duly updated its D31a form, used alongside IHT100 to notify the department about a settlor or transferor who falls outside that long-term residence test, on 24 September 2026. Both rulings show that a settlor's or holder's claimed status can unravel in court years after a structure was put in place.

Griffin's dispute, reported by PHTM, spanned tax years 2013 to 2020. Born in England in 1942 and resident in the UK for more than seven decades, he argued he had inherited an Irish domicile of origin through his father, which would have given his foreign investment income favourable treatment under the old non-dom rules. The tribunal was not persuaded, working through decades of personal history, from his London roots to his Arsenal season ticket and his English golf club memberships, along with his father's move to London in the 1930s. Judge Snelders concluded that Griffin's father had likely acquired an English domicile by 1959, which Sir John then inherited in turn.

He retains the right to appeal.

The Jersey case turned on a different kind of mistake. A 70-year-old settlor set up the Puffin Trust in April 2018, believing it would protect her wealth and ease its passage to her family. Her adviser, however, had miscalculated when she would become UK-domiciled, overlooking years she had previously spent in the country, Bailiwick Express reported. The error left the trust exposed to an initial inheritance tax charge of roughly £4.245 million, interest of £1.63 million by July 2026, and the prospect of further penalties, before the court stepped in.

"The advice she received was simply wrong."

The court declared the trust invalid and unwound the transfers, so that the assets are now treated as having always been held directly by the settlor. No inheritance tax is due as a result, though the judgment notes that some adverse income tax and capital gains tax consequences remain. The settlor herself told the court the outcome bore no resemblance to what she had been promised: "These consequences were not merely unexpected but wholly inconsistent with the advice I had received and the careful and entirely standard planning I believed I was implementing when I established the Trust."

As PPLI.com reported when the two rulings landed, "the two rulings are a blunt reminder to UK-connected families that domicile and trust structuring are tested in court years after the advice was given, often with the original adviser long gone." The old remittance basis ended in April 2025, but HMRC's enquiry window into pre-2025 domicile years remains open, which leaves Griffin's case as a live warning for anyone whose status from that period has yet to face scrutiny.

Updated on 14 October 2026: this article was revised and re-checked against its sources.

Sources

Form: Tell HMRC about a transferor or settlor who is not a long-term UK resident (D31a) (HM Revenue and Customs, 24 Sep 2026)
Addison Lee founder Sir John Griffin loses £20.5 million domicile fight with HMRC (PHTM, 12 Oct 2026)
Court unwinds £17.3m trust after "simply wrong" tax advice (Bailiwick Express, 12 Oct 2026)