A residence is a place of some permanency, while a domicile is a true, fixed permanent home to which an individual intends to return after an absence. If a person is considered a resident of California, they generally have to pay California state income tax on all of their income.Do you need to be California residents to register as domestic partners? There is no California residency requirement in the law. "Domicile" is the one location with which for legal purposes a person is considered to have the most settled and permanent connection.