IHTM27262 - Foreign property: specific British Government Securities: reversionary interest in exempt securities
Reversionary interests in settled property are usually treated as excluded property for Inheritance Tax but there are some exceptions.
Where a reversion is not itself excluded property (for example, because it has been purchased), any exempt securities that are part of the property to which the reversion relates are not excluded from the tax charge. This is the case even if the transferor or reversioner is domiciled and ordinarily resident abroad. In this situation your valuation of the reversion should include the exempt securities.