A step-child who has not been formally adopted is not legally considered to be a child of the deceased. They are not entitled to any portion of the deceased's estate under the law of intestacy and will not inherit unless the deceased expressly names them in their will.

However, step-children can, in some circumstances, apply under Part 6 of the Succession Act 2023 (SA) for a family provision order if they believe the will of the deceased or the law of intestacy will leave them without adequate provision for their proper maintenance, education or advancement. See Inadequate provision.