If you make 0 a year living in South Africa, you will be taxed 0. That means that your net pay will be 0 per year, or 0 per month. Your average tax rate is 0 and your marginal tax rate is 0. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of R 100 in your salary will be taxed R 0, hence, your net pay will only increase by R 100.

A R 1,000 bonus will generate an extra R 1,000 of net incomes. A R 5,000 bonus will generate an extra R 5,000 of net incomes.