South Africa has been a pioneer on climate change policy internationally, despite being a carbon intensive developing country. In 2010, it began a process to develop a carbon tax to help put a price on carbon, and incentivise the behavioural changes needed to support a transition away from business as usual development. But despite an inclusive and iterative policy design process, there has been resistance, particularly from affected business interests. In 2014 the decision was taken to delay the proposal until 2016. This paper reflects on the evolution of the carbon tax proposal, and draws lessons from this experience for the design of such policy instruments.