IHTM16161 - Foreign Property in a trust: introduction
If the settlor was domiciled within the UK when the settlement was made then the foreign property is chargeable to IHT. (see IHTM13000 for domicile guidance)
However, under IHTA84/S48 (3) foreign property which is comprised in a settlement is excluded property if the settlor was not domiciled in the UK at the time the settlement was made (or in relation to property that was added later, at the time the addition was made).
The next page gives further details of excluded property.