Income tax for a sole proprietor on business profit at individual rates with rebates.
Income tax
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Taxable income
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Retirement deduction
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You and the business are one taxpayer
A sole proprietor is not a separate legal person from the business. There is no company, no second tax return, no flat company rate. The profit your business makes is your income, full stop, and it lands on your personal tax return alongside any salary, rental, or investment income you also earn. This calculator works exactly that way: it takes your business profit, adds any other income, and runs the total through the individual income tax scale, then subtracts the age rebate everyone is entitled to.
That has an upside and a downside. The upside is simplicity and access to the rebates and deductions individuals enjoy. The downside is that a thriving sole proprietorship can push you into the higher individual brackets quickly, where the top rate this calculator applies is 45 percent. Many owners reach a point where incorporating, and paying the company rate instead, starts to look attractive, though that decision involves far more than the headline rate.
Profit flows onto your personal return
South Africa taxes individuals on a seven-band progressive scale. Each band taxes only the income that falls inside it, so your first rands are always taxed lightly and only the top slice meets your highest rate. The rates this calculator applies for 2025/26 run from 18 percent on income up to R237,100, stepping up through 26, 31, 36, 39 and 41 percent, to 45 percent above R1,817,000. After the scale produces a gross tax figure, the primary rebate of R17,235, which is the amount used here, is taken off, with extra rebates layered in once you turn 65 and again at 75. Treat each of these numbers as the tool's assumption and confirm the current figures with SARS before you rely on them.
Tax on R500,000 of profit
Picture a sole proprietor under 65 with R500,000 of business profit, no other income, and no retirement contribution. Running R500,000 up the scale gives a gross tax of about R117,507, and subtracting the R17,235 primary rebate leaves R100,272 payable. The table walks through the bands that build up that figure.
| Band of taxable income | Rate | Tax |
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The retirement contribution lever
The single most effective way a sole proprietor reduces this bill is a retirement fund contribution. Contributions to a pension, provident, or retirement annuity fund are deductible up to 27.5 percent of income, capped at R350,000 a year, which are the limits this calculator uses. Enter a contribution and the deduction lowers taxable income before the scale is applied. On the R500,000 example, putting R60,000 into a retirement annuity drops taxable income to R440,000 and the tax to R81,672, a saving of R18,600 in the first year, which is the contribution working at your 31 percent marginal rate.
That is the lever to pull deliberately before the tax year closes at the end of February. A common mistake is leaving the contribution until you file, by which point the year of assessment has ended and the chance to shelter that income has passed.
Provisional tax catches almost every owner
Because business profit is not subject to PAYE deducted by an employer, a sole proprietor is almost always a provisional taxpayer. That means you estimate your annual taxable income and pay tax twice during the year, by the end of August and the end of February, with a third optional top-up payment afterwards. Underestimate badly and SARS can levy penalties and interest. The practical habit that saves owners grief is to set aside roughly your marginal rate of every invoice into a separate account as it comes in, so the provisional payments do not arrive as a shock.
Which business expenses can I deduct from profit?
You deduct expenses actually incurred in producing the income, such as stock, rent on business premises, professional fees, and the business-use portion of your phone, internet, and vehicle. Private and domestic costs are not deductible. The profit you enter into this calculator should already be net of those expenses, since the tool taxes profit, not turnover.
Do I have to register for VAT as a sole proprietor?
Only once your taxable turnover crosses R1 million in any rolling twelve months, at which point registration is compulsory. You may register voluntarily above R50,000 of turnover. VAT is separate from the income tax this calculator works out, and being a sole proprietor does not by itself trigger it.