SARS provisional tax calculator
Work out IRP6 payments, due dates, penalties and interest for an individual, a company, or a small business corporation. It is free, it runs in your browser, and it asks you for nothing.
Tax on the estimate for the full year
R288,293
- First period paymentDue 31 August 2026
- R144,147
- Second period paymentDue 26 February 2027
- R288,293
- Third period dateSection 89quat effective date
- 30 September 2027
Rates verified against SARS on 23 August 2026, for the 2027 year of assessment.
The arithmetic behind the calculator
Paragraph 20 of the Fourth Schedule to the Income Tax Act lets SARS add a 20 percent penalty when the second provisional estimate lands too low. At or below R1 million in taxable income the estimate avoids the penalty by reaching either 90 percent of the actual figure or the basic amount, whichever is lower. Above R1 million the basic amount falls away and the estimate has to reach 80 percent of the actual figure. Section 89quat adds interest on top once the assessment is out.
The calculator runs that arithmetic the way the C-Suite Commercial engine runs it in production: IRP6 payment for the period, threshold that applies to the client, due date adjusted for South African business days, and indicative interest, before the figure is committed.
Estimate for review only. It is not a SARS assessment or tax advice, and it excludes capital gains, lump-sum tables, ring-fencing, and foreign income. Rates verified against SARS on 23 August 2026. The prescribed rate defaults to 10.25 percent, the SARS Table 1 rate from 1 March 2026, and it changes quarterly, so re-check it before you rely on the interest figure.
Common questions
- How do I calculate provisional tax?
- Estimate the taxable income for the year, work out the normal tax on it, then halve that figure for the first period and deduct the first payment for the second. Employees tax and allowable credits come off before the amount due. The calculator does this arithmetic for the period you choose and shows the paragraph 20 threshold alongside it, so the estimate is tested before it is filed.
- When is provisional tax due in 2026?
- For a February year end, the first period is due by the end of August 2026 and the second by the end of February 2027. When the last day falls on a weekend or a public holiday, SARS treats the last business day before it as the deadline, and the calculator applies that adjustment to the exact date for you.
- What is the paragraph 20 underestimation penalty?
- A 20 percent penalty on the shortfall when the second provisional estimate comes in too low. At or below R1 million in taxable income, the estimate is safe once it reaches the lower of 90 percent of actual taxable income or the basic amount. Above R1 million it has to reach 80 percent of actual taxable income, and section 89quat interest can run on top of the penalty.
- Does this calculator store anything I type in?
- No. Every figure is worked out in your browser, and the numbers you type are masked before anything leaves it, so they stay on your own device. There is no sign-up and no email field. Anonymised analytics and an anonymised session replay do run across the site so we can see which pages confuse people, and one click in the footer switches both off.
More on how the penalty is worked out, and what triggers it, in our guide to the underestimation penalty.
One client at a time, or the whole book
This works out the exposure on a single estimate. A practice carrying a few hundred provisional taxpayers has the same question across every one of them, in the same week. The C-Suite pilot runs that check across your own client book for a week, at no cost, so you can see the exposures before the deadline rather than after the assessment.