Many South African companies are also listed on international exchanges, such as in the U.S. Filings from companies with their 'Principal executive offices' located in South Africa can be accessed on the U.S. Securities and Exchange Commission's EDGAR (Electronic Data Gathering, Analysis, and Retrieval) system
The Southern African Legal Information Institute (SAFLII) database of court cases can be searched for specific companies.
Companies and Intellectual Property Commission (CIPC) has an entity search where you can look up information about a specific company using enterprise name, number of director ID.
Master of the High Court hosts a Trust Search. You can also search for deceased, liquidation, curator and insolvency via the same link.
International databases and registers are also useful for accessing information on companies (and individuals associated with companies) based or operating in South Africa.
Global list is available on Wikipedia
OpenOwnership aggregates beneficial ownership information from various sources
European Union (EU) company registers for several countries are accessible via this central search facility
Open Corporates is a commercial company search facility
Institute of Directors South Africa (IoDSA) publishes PDFs of registered and chartered directors.
National Credit Regulator (NCR) provides access to databases of registered (and cancelled/ lapsed) credit providers, debt counsellors, credit bureaus, alternative dispute resolution providers, and payment distribution agencies.
Construction companies are registered with the Construction Industry Development Board (CIDB). Access the register here.
Mining company activity for South Africa is available via the list of operating mines by Province.
Other sectors have their own registers for providers such as in healthcare (e.g. licensed pharmacies, doctors and therapists).
Resource Projects lists payments made by corporates to governments (e.g. taxes and royalties) - mainly related to oil, gas and mining projects - including South Africa.
Land Matrix tracks large-scale land acquisitions.