IHTM12196 - Succession: Simultaneous deaths (commorientes): Death of younger (England & Wales)
When property devolves from the estate of an elder person to the estate of a younger under Law of Property Act/ S184 the effect of IHTA84/S4(2) is that the property which devolves in this way is not taxable under IHTA84/S4(1) on the death of the younger.
There is an example showing this on the next page (IHTM12197).
Joint property that passes to the younger by survivorship and funds settled before the death of the elder which pass into the estate of the younger are also not taxable under S4(1) on the death of the younger.