What does domicile mean?
Domicile is the country regarded as your natural home. You can only have one domicile at any time. Your domicile can be of origin, choice or dependency. However, there are also specific rules which can deem you to be UK domiciled even if you do not have a UK domicile of origin, choice or dependency if you have been UK resident for 15 out of the past 20 years.
Where you are domiciled is relevant for a number of taxes. A British domiciled person is liable to pay inheritance tax on their entire estate wherever it is in the world. A ‘non-dom’ is liable to pay inheritance tax only on their UK property (including UK residential property held through overseas entities).