Your effective tax rate is the average rate you pay across all your taxable income, after applying every bracket you fall into and subtracting rebates. It’s calculated as total tax divided by total taxable income — useful for comparing tax burden year on year or across earners, but not the right number for marginal decisions.
Because South Africa’s income tax is progressive, the effective rate is always lower than the marginal rate for anyone earning above the tax threshold. An earner on R600,000 in 2026/2027 has a marginal rate of 36% but an effective rate of about 23.4% — the lower brackets bring the average down.
The gap between marginal and effective shrinks at top-bracket incomes, where most of your earnings fall in the 45% band, and is widest for middle earners whose income spans several brackets. SARS’s assessment notice shows both rates explicitly.