South Africa, like any other country, strives towards greater tax revenue mobilisation. One possible explanation to low revenue levels is non-compliance by taxpayers. Given its implications for the provision of public goods and services, the government has instituted various enforcement measures, including (among others) reprieves (amnesties and voluntary disclosure programmes) to delinquents who voluntarily disclose their previously unreported income. However, evidence on the efficacy of these measures show mixed responses in developed countries, making it imperative to analyse these policy measures in more depth for developing countries. Against this background, we examined taxpayers’ behavioural responses to once-off and permanent voluntary disclosure programmes. Using laboratory experiments, we found that both once-off and permanent voluntary disclosure programmes are effective in increasing compliance in the short-term, and only when they are accompanied by increased enforcement measures. The results also show that both once-off and permanent voluntary disclosure programmes (with or without increased enforcement) have insignificant long-term effects on compliance. Furthermore, a once-off voluntary disclosure programme is more effective than a permanent voluntary disclosure programme in stimulating compliance. As such, it is recommended that authorities avoid permanent voluntary disclosure programmes.