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The Biggest Tax Mistakes South Africans Will Make in July 2026
Every July, millions of South Africans make the same mistake.
It costs them thousands of rands. It takes seconds to make. And by the time most people realise what’s happened, the window to fix it has already closed.
Tax Season 2026 opens on 1 July. SARS will issue pre-filled tax returns to millions of eligible taxpayers, and those returns will finalise automatically. If you do nothing, the auto-assessment becomes your official return – missing deductions and all. Your refund will be calculated on incomplete figures, and most people will never notice.
It won’t be. Not fully. And for many people, the shortfall will never be recovered.
This article explains exactly what is happening, why it is so easy to get wrong, and what you need to do differently this July.
What Is a SARS Auto-Assessment And Why Does It Look So Convincing?
A SARS auto-assessment is a pre-populated income tax return generated on your behalf at the start of filing season. SARS builds it using data it has received from third parties — your employer, medical aid scheme, retirement annuity provider, and bank.
It arrives in your eFiling profile looking official, complete, and settled. There is even a summary showing income, deductions, and the refund or amount owing. For most people, it looks done.
That is precisely the problem.
The auto-assessment is only as complete as the data SARS received. It reflects what third parties told SARS — not what you are actually entitled to claim. And there is a critical category of deductions that will never appear on any auto-assessment, no matter how good SARS’s systems are.
What SARS Cannot Know And Will Never Include
This is the part of the tax system that most South Africans are never told. Certain deductions require you to provide the information. SARS has no access to this data. It cannot calculate these deductions. It will never include them automatically. And if your auto-assessment finalises without them, they are gone for that tax year, unless you file a correction.
Home Office Deductions
Many South Africans who work remotely qualify for a Home Office Deduction, yet never claim it because they’re unsure of the rules.
If you worked from home in a dedicated, exclusively-used workspace for more than 50% of the tax year, you may qualify to deduct a portion of your home running costs
✅ Rent
✅ Rates and municipal taxes
✅ Electricity and utilities
✅ Levies
✅ Maintenance and cleaning costs
⚠️ The challenge is that SARS has strict qualifying criteria and documentation requirements. Incorrect claims can trigger queries, while missed claims could mean paying more tax than necessary.
Out-of-Pocket Medical Expenses
Your medical aid scheme reports contributions to SARS. It does not report the co-payments, specialist fees, dental costs, and prescribed medication you paid personally that your scheme did not cover. These additional costs qualify for medical expense relief — but only if you declare them.
Retirement Annuity Timing Gaps
Your RA provider submits data to SARS, but timing differences between when you paid contributions and when the data was submitted mean your auto-assessment may reflect a lower RA deduction than what you actually paid. The annual deduction is up to 27.5% of taxable income with a cap of R430,000 — a timing gap is not a small issue.Business Travel Claims
If you receive a travel allowance, SARS generally includes part of that allowance in your taxable income during the year. If you maintained an accurate logbook and your qualifying business travel supports a deduction, you may be entitled to claim additional travel expenses when submitting your return.
SARS cannot calculate this automatically because it does not have access to your logbook.
Section 18A Charitable Donations
Donations made to approved Public Benefit organizations (PBO’S) may qualify for a tax deduction, subject to the applicable legislative limits. To claim the deduction, you must retain and submit your valid Section 18A Certificates. SARS cannot include this automatically
Why This Mistake Is So Easy to Make
Understanding why this mistake is so common matters because it is not a failure of intelligence or effort. It is a failure of information.
The assessment looks finished. SARS’s eFiling system presents your auto-assessment with summary, a calculation, and a refund or payment figure. Nothing in the user experience signals that the return might be missing significant deductions. The average taxpayer sees a refund figure and assumes it is the right one.
Most people don’t know what they don’t know. The deductions that SARS misses — home office, out-of-pocket medical, RA timing gaps, travel logbooks — are not commonly discussed. Most taxpayers have never been told these deductions exist, let alone that they must be claimed manually.
Doing nothing feels safe. Because the auto-assessment finalises automatically, inaction feels like the path of least resistance. There is no moment where a taxpayer feels they made a decision. The return simply closes, and the money is left behind.
There is no second notification. Once your auto-assessment finalises, SARS does not follow up to tell you that you missed deductions. You are assessed on the figures provided, your refund is calculated at that level, and the file is closed.
How to Avoid the Biggest Mistake This July
The solution is not complicated. But it requires acting not assuming the auto-assessment is correct and moving on.
Step 1: Do not assume your auto-assessment is correct
When it arrives in your eFiling profile from 1 July, treat it as a first draft, not a final document. Log in, open it, and review every figure carefully before deciding whether any changes are required.
Step 2: Gather your supporting documentation.
Before 1 July, collect your IRP5, medical aid tax certificate, RA IT3(a) certificate, investment income statements, and any receipts for out-of-pocket medical costs. If you have a travel logbook, locate it. If you worked from home, calculate your office area ratio and annual home costs.
Step 3: Compare the assessment to your documentation.
Check each figure on the assessment against your records. Pay particular attention to: – The medical aid figure — does it match your scheme’s tax certificate? – The RA figure — does it match your IT3(a) certificate exactly? – The income figure — does it match your IRP5? – Missing deductions — home office, travel, medical out-of-pocket, donations
Step 4: If anything doesn’t match — submit an updated tax return.
If your auto-assessment is incomplete or contains incorrect information, you can submit an updated ITR12 through SARS eFiling or the SARS MobiApp. This is a normal part of the filing process and allows you to ensure your return accurately reflects your income, deductions and tax position.
Individual non-provisional taxpayers generally have until 23 October 2026 to submit their return.
Step 5: Use a registered tax practitioner.
This step is optional — but it is where most South Africans recover the money they would otherwise leave behind. A registered tax practitioner reviews your assessment against your complete financial picture, identifies every deduction you qualify for, and submits a return that SARS processes without query.
When exactly does the auto-assessment window open and close in 2026?
Auto-assessments are issued between 1 July and 12 July 2026. If your assessment is correct, you generally do not need to take further action. If it is incomplete or incorrect, you should submit an updated ITR12 through SARS eFiling or the SARS MobiApp before the applicable filing deadline
What happens if my auto-assessment is incomplete?
If your auto-assessment does not accurately reflect your tax affairs, you may submit an updated ITR12 during the filing season. If an assessment has already been finalised and you later identify an error, you may also be able to submit a Request for Correction (RFC) through SARS eFiling, subject to SARS’ rules and applicable time limits. A registered tax practitioner can advise on the most appropriate course of action based on your circumstances.
Will updating my auto-assessment trigger an Audit?
No, updating your tax return where information is missing or incorrect is a standard part of the SARS filing process. SARS selects returns for verification or audit using its own risk assessment processes, and simply updating your return does not automatically trigger an audit.
How do I know if I qualify for a home office deduction?
You qualify if you worked from home for more than 50% of the year in a dedicated, exclusively-used workspace, and your employer requires you to work from home. If you meet these criteria and have not been claiming this deduction, your prior year returns may also be worth reviewing.
Is it too late to prepare before Tax Season opens on 1 July?
No but the window is narrow. Gathering your documentation now (IRP5, medical aid certificate, RA IT3(a) certificate, travel logbook) and booking an appointment with a tax practitioner before 1 July gives you the best possible position when auto-assessments arrive.
Don't Make the Most Expensive Click of 2026
Tax Season 2026 opens on 1 July. One of the biggest financial mistakes South Africans can make this July is assuming that an auto-assessment is automatically complete. While it provides an excellent starting point, it cannot include information that SARS has not received or deductions that require supporting information from you. Taking the time to review your assessment carefully could make a significant difference to your tax outcome. If you are unsure what you are looking for, speak to someone who does this every day.
At TTT Financial Group, we check every figure, identify every missed deduction, and file correctly on day one of tax season, so our clients are first in the refund queue. Tax Season opens 1 July.
Our calendar is filling. Book your 2026 tax review with TTT Financial Group