If you are planning a visit to South Africa there is a limit to the amount of currency you allow to bring in. I am saying the amount of cash you can bring in at any time without having to be questioned or declared by filling a form with custom officers.
For cash in South African Rand (ZAR), the limit is 25,000ZAR. For combinations of cash in other currencies, the limit is US$10,000 (or equivalent). Any amount of cash equal to or greater than US$10,000 should be declared by filling a form with the custom officer at the point on entry to South Africa.
South Africa custom act states that visitor to South Africa and South African residents are not permitted to import or export South Africa Reserve Bank Notes or any bank notes of other member countries of the Common Monetary Area (CMA) Lesotho, Namibia and Swaziland in excess of a total value of R25000 per person.
Visitors to South Africa are allow to bring in foreign currency in any format into South Africa which can be converted into Rand at any local banks.