The short answer is no – If you are not legally adopted and there is no valid will which bequeaths the estate, or part of it, to you, you will not be entitled to inherit.
To inherit where there is no valid will – referred to as intestate succession – requires a child to be either the biological or adopted child of the parents. Adoption is the process where an adult assumes the parenting rights and responsibilities from the biological parents or legal guardians of a child who is under 18 years of age. Adoption is intended to effect a permanent change in the status of a child and must take place through a court order. Children who have been legally adopted in terms of our law are deemed to be the descendants of their adoptive parents, and cannot therefore be a descendant of their biological parents and inherit intestate from them. An adopted child can therefore share in the estate of a deceased adoptive parent in the same way as a biological child, and will accordingly be able to inherit intestate should there be no will.
To address the question of whether growing up with parents is sufficient to entitle a person to inherit from them even if not formally adopted, our courts have found that unless an adoption process has been completed, a child that is not the biological child of the parents cannot inherit intestate from them irrespective of whether the child has grown up with the parents or even had an adoption process underway. Such a child will however remain a natural descendant of their biological parents and will be entitled to inherit intestate from such parents.
In your situation, where you have not been adopted, you would therefore not be able to inherit intestate from your parents should they pass away without a will. It would thus be appropriate to raise the issue of inheritance with them and if necessary have a will drafted that establishes your right to inherit from them.