Where there is no will (an 'intestate estate')
A domestic partner is entitled to inherit an intestate estate (see Distribution of an intestate estate). There is no requirement that a person be legally married to the deceased in order to inherit.
Where there is a will
A domestic partner is eligible to apply under Part 6 of the Succession Act 2023 (SA) for a family provision order if they believe the will of the deceased will leave them without adequate provision for their proper maintenance, education or advancement. See Inadequate provision.