Where, on or after 25 January 1984, property becomes subject to a discretionary trust by or in consequence of any disposition, the trust is treated as having the beneficial entitlement in possession to an absolute interest in so much of that property (and property representing it and its accumulated income) as remains subject to the trust on the latest of: (a) the date the property became subject to the trust; (b) the disponer's date of death; or (c) where there are principal objects, the date on which there ceases to be a principal object below the prescribed age (under 25 where the property became subject between 25 January 1984 and 31 January 1993; under 21 where it became subject on or after 31 January 1993). That latest date is the date of the inheritance and the trust and trustees are treated together as a person for the purposes of the Act.

Supplementary provisions deem a discretionary trust created by will to take effect on the testator's date of death; deem property subject to a discretionary trust on 25 January 1984 or on 31 January 1993 to have become subject on those respective dates; provide that an interest in expectancy, and an interest in a life assurance policy until it becomes an interest in possession under section 41, are not "property" for these purposes until they crystallise or are represented by non‑expectancy property; and prevent multiple charges by charging such property once only, on the earliest occasion it would be chargeable.