ATXP6 UK
Syllabus A3. Inheritance Tax A3a. Basic principles of computing transfers of value

A3a. Chargeable persons

Syllabus A3a)

The basic principles of computing transfers of value

Chargeable persons

A person who is domiciled in the UK is liable to IHT in respect of their worldwide assets. 

Additionally, the only relevant chargeable person is an individual. 

Married couples (and registered civil partnerships) are not chargeable persons because each spouse (or civil partner) is taxed separately.