The short version

Each July, SARS uses data already on file — IRP5 from your employer, IT3(b) from your bank, medical-scheme contribution certificates, and retirement-fund statements — to pre-fill an ITR12 income tax return. They do the arithmetic and tell you what they think you owe (or what's owed back to you). You have 40 business days to look at it, fix anything they got wrong, and submit. Do nothing and the estimate becomes final.

For salaried taxpayers with simple finances — one employer, no side income, contributions only via medical scheme and pension fund — the auto-assessment is usually correct. For everyone else, the things SARS doesn't see can move the result by tens of thousands of rand.

What SARS sees automatically

Third parties report directly to SARS. By the time you receive your auto-assessment, the following data is already loaded:

If all your income and deductions sit inside that list, the auto-assessment is genuinely accurate. The risk is what falls outside it.

What auto-assessment misses

SARS only knows what third parties tell them. Anything you receive in cash, claim out of pocket, or earn from sources without a reporting obligation has to be added manually:

What to do when the auto-assessment lands

Log into eFiling or the SARS MobiApp and open the assessment. Compare it to your records:

  1. Check the IRP5 totals match. If you changed jobs mid-year and one employer didn't submit, the gross income will be understated. Add the missing IRP5 and re-run.
  2. Check medical contributions. The scheme certificate is usually right, but verify the number of beneficiaries reported. Add any out-of-pocket medical expenses.
  3. Check retirement contributions. If you contributed to an RA outside payroll, confirm the IT3(f) amount is reflected. If not, add it.
  4. Add anything from the "missed" list above. Each addition either reduces tax owed or increases your refund.
  5. Re-submit. SARS issues a revised assessment, usually within minutes.

If the assessment is correct as-is, accept it on eFiling. Refunds are typically paid into your nominated bank account within 72 hours.

If you disagree

Two paths:

Don't ignore an auto-assessment that's wrong. SARS can collect any amount they think you owe via a third-party demand to your bank, your employer, or anyone who owes you money. And any refund you were entitled to but didn't claim simply stays with SARS.

Provisional taxpayers

If you're a provisional taxpayer (sole proprietor, freelancer, rental landlord), you're typically excluded from auto-assessment — your ITR12 must be filed manually by the 31 January provisional-taxpayer deadline. SARS still pre-fills what they have, but you have to complete the full return yourself. The IRP6 calculator covers your bi-annual provisional payments.

Practical takeaway

For pure-salaried earners with one job, a medical scheme, and a pension fund, auto-assessment is a 5-minute formality and usually accurate. For anyone with rental, freelance, donation receipts, or capital gains, it's a starting estimate that often understates your refund (or overstates your tax). Open it, add what's missing, resubmit. Do not let it become final by default.