What is domicile?
Domicile is an old legal concept which indicates the country you regard as your home. You are domiciled in a State having a common system of law, for example, Scotland, England, Ireland, New York State. In other words, you cannot be domiciled in a federation or confederacy.
You acquire your domicile of origin when you were born. This is generally your father’s domicile at the time of your birth, but if your parents were unmarried when you were born, you take your mother’s domicile. Until you reach 18 years of age, your domicile follows that of your father (or your mother if your parents were not married). This is your domicile of dependence. If you are a woman and you were married under Irish law before 2 October 1986, you continue to have your husband’s domicile. This is also a domicile of dependence. If you were married after 2 October 1986, you maintain your own domicile.
When you reach 18 years of age, you are free to choose your own domicile. You can abandon your domicile of origin and acquire a domicile of choice by taking up residence in another country with the intention of residing permanently in that country.
It is difficult to abandon your domicile of origin and acquire a domicile of choice. To do so, you must show clear evidence that you have taken up residence in your new country, and that you intend to stay there permanently.
If you are not domiciled in Ireland for a tax year, you are taxed on your income arising outside Ireland and the UK only if you bring that income into Ireland.