Before 2018, Insurance companies must be registered as South African public companies and have their head office in South Africa. Branches of foreign insurers are not allowed. As of 1 July 2018, conduction of insurance business via a branch is allowed for foreign reinsurers only. Others remain subject to a local incorporation requirement.
"Definitions
1. (1) In this Act, unless the context indicates otherwise—[…]
‘‘branch of a foreign reinsurer’’ means an operating entity of a foreign reinsurer that is not a legal entity separate from the foreign reinsurer;[…]
‘‘foreign branch of an insurer’’means an operating entity of an insurer that is part of the insurer in terms of its organisation and is not a legal entity separate from the insurer, but is established outside of the Republic;
‘‘foreign reinsurer’’ means an institution authorised and supervised by a regulatory authority to perform business similar to reinsurance business as defined in this Act under the laws of a country other than the Republic;
[...]
Part 3 -  Branches of foreign reinsurers and Lloyd’s underwriters
Conducting of insurance business by branches of foreign reinsurers and Lloyd’s underwriters
6. (1) A foreign reinsurer may conduct insurance business in the Republic through a branch of that foreign reinsurer if the foreign reinsurer— (a) is granted a licence under Chapter 4; (b) establishes a representative office in the Republic in accordance with Chapter 5; and (c) establishes a trust in the Republic in accordance with Chapter 6.
[...]
Requirements for licence
22. (1) In order to qualify for licensing as an insurer—
(a) a person—
(i) in the case of a person that intends to conduct microinsurance business only, must be a profit company or a non-profit company registered under the Companies Act, or a co-operative registered under the Co-operatives Act;
(ii) in the case of a person that intends to conduct reinsurance business only, must be a public company or state-owned company registered under the Companies Act, a co-operative registered under the Co-operatives Act or a branch of a foreign reinsurer; and 
(iii) in any other case, subject to section 70, must be a public company or state-owned company registered under the Companies Act, or a co-operative registered under the Co-operatives Act; [...]" (Insurance Act No 18 of 2017, as amended)
Insurance Act No 18 of 2017, as amended
[<a href="https://www.resbank.co.za/en/home/publications/publication-detail-pages/prudential-authority/pa-post-insurance/act/2018/8571">Act</a>]