Residency is where one chooses to live. Domicile is more permanent and is essentially somebody's home base.Domiciled in California, but outside California for a temporary or transitory purpose. There are more factors for determining residency. Having a CA domicile makes a person a CA tax resident, until she acquires a new domicile or is "absent for a longterm purpose. Domicile is intended to be permanent rather than temporary, whereas residence means living in a particular locality and requires mere physical presence. If a person is considered a resident of California, they generally have to pay California state income tax on all of their income. The terms "domicile" and "residence" are often used interchangeably, but from a tax and legal perspective, they are not the same. Simply, a person's domicile is the place where they have their most settled legal connection.