How Your Bonus Is Taxed (and Why It Feels Like So Much)

Every year, the same disappointment: the bonus that looked like a windfall arrives in your account looking distinctly smaller, and it feels like it was taxed at some punishing special rate. The good news is there's no special "bonus tax." The slightly less good news is that the way PAYE works can make a bonus genuinely lose more to tax than your normal salary does. Both things are true, and here's how.

A bonus is simply added to your income for the year, and taxed on the same sliding scale as everything else. There is no separate, higher rate for bonuses. What changes is which band the bonus falls into. Your regular monthly salary has already "used up" the lower-rate bands. So your bonus sits on top of that — and the rand in it are taxed at your highest, marginal rate, not your lower average rate.

An example makes it clear. Suppose your salary puts your top rand in the 31% band. Your average tax rate across your whole salary might be only 20%-something, because the early bands are taxed at 18% and 26%. But your bonus doesn't get the benefit of those low early bands — they're already spoken for. The whole bonus is taxed at that 31% marginal rate. So a R20 000 bonus might lose R6 200 to PAYE, even though your salary as a whole is taxed at a gentler average. Nothing has gone wrong; the bonus is just being taxed at the rate that applies to your next rand, which is always higher than your average.

There's also a payroll quirk worth knowing. Some payroll systems, when they see a big one-off amount in a single month, briefly calculate as if you earn that much every month — which can over-deduct in the bonus month. If that happens, it usually evens out over the rest of the tax year or comes back as a refund when you file. So an unusually brutal-looking bonus month isn't always the final word.

If you want to soften the blow legitimately, a bonus is a natural moment to top up a retirement annuity — that contribution is deducted before tax, so it directly reduces the tax on the bonus while moving the money into your own long-term savings rather than SARS's pocket.

This is general information, not tax advice. To estimate the tax on a salary plus bonus, use the calculator with your annual figure.