In an effort to curb child trafficking, the South African government has instituted new regulations pertaining to children coming into and out of the country. All children under 18 years old must have a copy of their unabridged birth certificate with them (or equivalent from their own country). However, if you have applied for a VISA to enter South Africa, this will not be needed. So this new rule applies to all visa-free entries and exits.
When travelling into Swaziland, the birth certificates will have to be shown at the South African exit border point. There are also requirements for children under 18 not travelling with both parents, or travelling without their parents at all. For more information, please go to the South African government’s Home Affairs website:-
Update at February 2016: