A very useful article from Mike Poverello regarding customs regulations and requirements in South Africa..
As of May 10 2013 an amendment to the South African Customs and Excise Act (91/1964) published in Government Gazette 36433, concerns an increase to the threshold for importation and exportation in the absence of customs registration.
General Registration Code 70707070 may be used by a party that is not registered as an importer or exporter with the South African Revenue Service, but wishes to import or export goods, provided that the following requirements are met:
The goods have a value of less than R 50,000 per consignment, subject to a limitation of three such consignments per calendar year; The goods are declared for home consumption (ie, consumption or use in South Africa) or temporary import or export; The importer or exporter is a natural person located in South Africa; and The importer or exporter states its identity number or taxpayer reference number on the customs declaration form.Traders should not confuse the above with the withdrawal of the General Registration Code from use by importers and exporters at land borders, which occurred during the course of 2012. In this regard refer to Rule Amendment Government Gazette No. 35178
Source : http://mpoverello.com