Your marginal tax rate is the rate that applies to the next rand you earn — the bracket your taxable income reaches, not the average rate across all your income. South Africa’s individual income tax has seven brackets, from 18% on income up to R245,100 (2026/2027) up to 45% on income above R1,878,600.
Marginal rate matters whenever you’re weighing additional income or a deduction. A R10,000 bonus is taxed at your marginal rate, not the average. A R10,000 retirement annuity contribution saves tax at your marginal rate too — so a 41%-bracket earner saves R4,100, but a 26%-bracket earner saves R2,600 on the same contribution.
Provisional taxpayers and contractors usually need to know their marginal rate to set sensible tax-aside amounts. PAYE earners can find theirs by looking up which bracket their annual taxable income lands in on the SARS tax tables.