Banks and lenders in South Africa do not approve loans by gut feel. There is a specific, regulated calculation process that every registered credit provider must follow before they can extend credit to you. Understanding exactly how that calculation works gives you two advantages: you can estimate your own qualifying amount before applying, and you can identify what to improve if you want a better outcome next time.
This article walks through the complete affordability calculation that South African banks and lenders use — step by step, in plain language, with the actual inputs and how each one affects the result. This is not a simplified version. It is the real process.
Step 1: Verify Gross Income
The affordability calculation starts with gross income verification. The bank or lender needs to confirm what you actually earn — not what you say you earn. This is done through:
- Payslip review: The payslip shows gross salary, all deductions, and net take-home. The lender reads the gross figure and all deduction line items. Every active PERSAL deduction, medical aid deduction, pension contribution, and loan deduction appears here.
- Bank statement analysis: The bank statement confirms that the salary deposits match the payslip figure, and that the net amount landing in the account each month is consistent. It also reveals debit orders that do not appear on the payslip — store account payments, insurance, subscriptions, and existing loan instalments running from the personal account.
- Third-party verification (for larger amounts): For personal loans above R100,000, some banks request an employment confirmation letter or direct employer verification by phone.
Income from multiple sources is aggregated — salary plus rental income plus verified gig platform income, for example. Income that cannot be verified in the bank statement or payslip is generally excluded from the qualifying income figure.
Step 2: Calculate Net Income After Statutory Deductions
The lender subtracts from gross income the statutory and fixed deductions that appear on the payslip:
| Deduction Category | What Is Included | How the Lender Treats It |
| Statutory deductions | PAYE income tax, UIF contribution | Always subtracted — non-negotiable obligations |
| Existing credit obligations on payslip | PERSAL loan deductions, garnishee orders | Subtracted in full — each reduces NDI rand-for-rand |
| Medical aid contributions | Employee contribution shown on payslip | Subtracted — fixed monthly obligation |
| Pension / retirement annuity contributions | If deducted on payslip | Subtracted — fixed monthly obligation |
| Other payroll deductions | Union fees, provident fund, garnishees | Subtracted — all payroll deductions reduce take-home |
Table 1: Step 2 deductions — what is subtracted from gross income to reach net payslip income
Step 3: Identify Additional Debit Orders From Bank Statements
This is the step most applicants do not anticipate being as thorough as it is. The lender reviews the bank statement for debit orders that do not appear on the payslip — store account payments, furniture account payments, insurance premiums paid from the bank account, gym memberships, subscription services, and any loan instalments not already showing on the payslip.
Every identified recurring debit order is added to the existing obligation list. The lender is building a complete picture of all committed monthly outflows — not just the ones the applicant volunteered in the application form.
Banks in South Africa typically run bank statements through automated analysis software that categorises all debit transactions. If you have a recurring debit that runs every month — even for a small amount — it will be identified, categorised, and subtracted from the NDI calculation. There is no point trying to hide obligations; the bank statement reveals them regardless.
Step 4: Apply the Living Expense Estimate
After all identified obligations are subtracted, the NCA requires lenders to also account for minimum living expenses. The lender cannot simply assume that whatever is left after deductions is all available for loan servicing — basic food, housing, transport, and utilities must be provided for.
In practice, lenders handle this differently:
- Declared expenses model: Some lenders ask you to declare your monthly living expenses on the application form and use those declared figures.
- Minimum living expense tables: Other lenders apply standardised minimum living expense tables published by bodies such as Stats SA, using household size and income band to estimate minimum expenses. Your declared expenses are compared to the table minimum — whichever is higher is used.
- Bank statement expense extraction: The most thorough approach — and increasingly common at mainstream banks — is to analyse the bank statement for cash withdrawals and card payments and categorise them as living expenses. This produces an actual rather than estimated expense figure.
Step 5: Calculate Net Disposable Income (NDI)
After Steps 1 through 4, the lender arrives at the NDI figure:
NDI = Verified Gross Income – Statutory Deductions – All Existing Credit Obligations – All Identified Debit Orders – Estimated or Declared Living Expenses
This NDI is the amount the lender uses to assess affordability. The proposed new loan instalment must fit within this NDI — and must leave the borrower able to meet basic living expenses without the loan payment creating hardship.
| NDI Calculation Example | Amount | Notes |
| Gross monthly salary | R12,000 | Starting point |
| Less: PAYE and UIF | – R1,300 | Statutory deductions |
| Less: Medical aid (payslip) | – R900 | Fixed payslip deduction |
| Less: Existing loan deduction (payslip) | – R1,200 | PERSAL or payslip deduction |
| Less: Store account debit (bank stmt) | – R350 | Identified from bank statement |
| Less: Insurance debit (bank stmt) | – R600 | Identified from bank statement |
| Less: Living expense estimate | – R3,500 | Food, transport, rent, utilities |
| = NDI available for new instalment | R4,150 | The qualifying figure |
Table 2: NDI calculation worked example at R12,000 gross salary — the R4,150 NDI is the figure that determines the maximum qualifying instalment
Step 6: Apply the Instalment Test
The lender takes the calculated NDI and applies the proposed new instalment. If the instalment fits within the NDI and the NDI calculation confirms no hardship, the application proceeds. If the instalment exceeds the NDI or would leave insufficient funds for living, the application is declined or the amount is reduced to a level the NDI supports.
Most lenders apply an additional buffer at this step — they do not approve instalments that consume the entire NDI, because that leaves zero margin for any income disruption. A practical internal limit of 60% to 80% of the NDI as the maximum instalment is typical, though this varies by lender and product.
Frequently Asked Questions
1. Can I see exactly how my affordability was calculated?
Yes — under the NCA, you have the right to receive an explanation of how the affordability assessment was conducted. If you are declined, you can ask the lender to explain which factors resulted in the decline. In practice, large lenders produce automated affordability reports that can be shared with the applicant. If a lender refuses to explain the basis of a decline, you can escalate to the NCR or the National Credit Ombud.
2. What if my declared living expenses are higher than the lender’s table?
The lender is required to use whichever is higher — your declared expenses or their minimum table. If you legitimately have higher-than-average expenses (large family, high rent, private school fees), declaring them accurately produces a smaller NDI and lower qualifying amount — but this is the honest picture. Understating expenses to improve the qualifying amount puts you at risk of approving a loan whose instalment you cannot actually service from your real budget.
3. Why was I declined when I earn a good salary?
Because salary is not the only input. The most common reasons for decline on a good salary are: high existing obligation load (vehicle, bond, store accounts, previous loans consuming most of the NDI), a poor credit score (missed payments, defaults, or judgements in the credit bureau record), a very short employment history with the current employer, or bank statements showing returned debit orders (which signal that existing obligations are already causing cash flow problems). The affordability calculation catches all of these.
4. If I pay off an existing loan before applying, does it immediately improve my assessment?
Yes — once a loan is settled and the deduction stops appearing on the payslip or bank statement, it is removed from the obligation list in the affordability calculation. The NDI improvement is immediate in the next payslip and bank statement cycle. Apply after the settlement is visible in at least one month’s bank statement so the lender can see the cleared obligation rather than having to take your word for it.
5. Do banks share affordability data between them?
Banks share credit bureau data — your repayment history, outstanding balances, and credit enquiries are visible to every registered credit provider who conducts a credit check on you. The affordability calculation itself is not shared, but the obligation data that feeds into it — every active credit account, its balance, and its monthly payment — is visible in the credit bureau report that every lender pulls when you apply. There is no hiding active obligations from any registered credit provider.
Final Thought
The affordability calculation is not designed to be a barrier. It is designed to protect both the borrower and the lender from an obligation that cannot be repaid. Understanding the six steps of the calculation means you can run it yourself before applying — you know roughly what your NDI is, you know what instalment it supports, and you apply with accurate expectations rather than disappointment. That is genuinely useful financial knowledge regardless of what salary level you are at.
Apply through ClearLoans and get matched to lenders whose qualifying criteria align with your affordability profile. Start at clearloans.co.za.
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