Southern Africa
The Southern African Customs Union has had EDI on its Trade Facilitation agenda since 2004. Nothing implemented.
Ghana
GCNet (Ghana Community Network Services) is a public-private partnership that mantains the Tradenet EDI network and the Ghana Customs Management System. A World Bank report detailing the development of the system can be found here.
South Africa
Used in the retail supply chain.
The South African Revenue Services Customs Division use it, and provide a good User Manual.