In this paper, we examine the relationship between the international tax environment and legislative complexity in South Africa’s international tax system. We suggest that the international tax environment is a double-edged sword. It causes complexity in South Africa’s tax legislation as it largely responds to the needs of OECD countries and produces tax rules to deal with ‘sophisticated’ tax problems and taxpayers (such as multinational enterprises). When such rules are transplanted into South Africa, they are typically more complex than local rules dealing with local taxpayers. On the other hand, the international tax environment offers ideas for ‘scientific’ drafting of South Africa’s tax legislation, which may lead to simplification and enhanced effectiveness in tax compliance and administration. We contribute to the literature on tax simplification by focusing on legislative complexity and distinguishing between intrinsic complexity and drafting-led complexity. We recommend ways of legislative simplification by drawing on the international tax environment.