In terms of the Births and Deaths Registrations Act, no person may assume or describe themselves under any surname other than that recorded in the population register or under which such person obtained permanent residence in South Africa.
For practical reasons, fortunately:
(a) a woman may assume the surname of her husband after marriage;
(b) a married or divorced woman or widow may revert to her maiden surname or any prior surname which she legally had;
(c) a woman, married or divorced, may also join to her married surname any prior surname she had at any time to form a double-barrel surname.
One may amend your surname by making application to the Director General in the prescribed form and show good cause for the change of surname and thereafter, once approved, have such change published in the Government Gazette.
Contact STBB for assistance.