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How Does Your Income Affect Home Loan Borrowing Capacity?
Your income plays a major role in determining home loan borrowing capacity, but lenders also assess expenses, debts, credit limits and repayment affordability. Learn how different income types, including salary, bonuses, rental income and self-employed earnings, are treated when calculating how much you may be able to borrow.
Published 30 October 20269 min read
How Does Your Income Affect Home Loan Borrowing Capacity?
Income is one of the biggest drivers of home loan borrowing capacity, but it works alongside your expenses, debts and the lender’s assessment rate. Lenders generally count income they can verify and consider reliable, then test whether it covers your living costs, existing debts and new repayments at a buffered interest rate. More assessable income may lift what you can borrow, but it never guarantees an outcome.
Quick Answer
Lenders work out how much income is left after tax, living expenses and existing debts, then test whether it can cover the new repayments at a higher “assessment” interest rate.
Income that is steady, documented and easy to verify (such as base salary) is generally counted most fully. Overtime, bonuses, rental income and self-employed income may be counted at a reduced level, or only with a history, depending on the lender.
Two people on the same income can have different borrowing capacity, because expenses, debts, credit limits, dependants and the lender’s policy all change the result.
Key Takeaways
Income is the starting point, not the whole answer. Lenders assess what is left after tax, expenses and debts.
“Assessable” income can differ from what you earn. Lenders decide what they will count, and some income types may be reduced or excluded.
Stability and evidence matter. Payslips, tax returns and a work or trading history help a lender see which income is reliable.
The assessment rate sits above your actual rate. APRA’s serviceability buffer of 3 percentage points applies to ADIs, so your income is tested against higher repayments than you will actually pay.
Lenders vary. The same income can produce different results at different lenders, and policies change over time.
How Lenders Use Income to Work Out Borrowing Capacity
Borrowing capacity (sometimes called borrowing power) is a lender’s estimate of the most it may be willing to lend you, based on your ability to repay. Income is the “money in” side of that calculation.
In simple terms, a lender builds a picture of your monthly surplus: assessable income, minus tax, minus living expenses and existing debt commitments. It then checks whether that surplus can cover the repayments on the new loan, calculated at a higher interest rate than the one you would actually pay.
Where the assessment rate comes from
APRA, the prudential regulator, requires authorised deposit-taking institutions (ADIs) to apply a minimum serviceability buffer of 3 percentage points above the loan’s interest rate, unless APRA determines otherwise. APRA allows ADIs to approve exceptions to their own lending policies in limited circumstances, provided these are managed prudently and within applicable regulatory requirements. An exception to an internal lending policy does not automatically waive APRA’s minimum buffer requirement. Any exception depends on the lender’s policy and the borrower’s circumstances.
Non-bank lenders are not ADIs and are not governed by APRA’s ADI standards in the same way. Many still test affordability at a buffered rate, and they set their own credit policies, so approach and results can differ.
Why this matters for income
Because repayments are tested at a higher rate, a given loan can look much heavier in the assessment than it does at today’s actual rate. Your income has to cover that tougher test, which is why borrowing capacity is usually lower than many people expect, and why a modest change in assessable income can change the result.
Gross Income vs Net Income: What Lenders Look At
Lenders usually begin with your gross (before-tax) income, then estimate the tax and other deductions to reach the income available for repayments. Tax is one reason a pay rise does not lift borrowing capacity dollar for dollar.
Compulsory study loan repayments can also reduce the money available for a home loan. The ATO calculates HELP repayments on “repayment income”, which is more than just taxable income, and the thresholds and rates are updated each year. A lender may take compulsory HELP repayments into account when assessing the income available for mortgage repayments. The treatment depends on the borrower’s circumstances and the lender’s serviceability policy.
How Different Types of Income May Be Treated
Not all income is treated equally. The table below describes general market practice. It is not any single lender’s policy, and lenders may treat each income type differently.
Income type
How lenders may treat it
What a lender may ask to see
Full-time salary (PAYG)
Generally the most straightforward income to assess, though a recent job change or probation period may be looked at more closely.
May be accepted where there is a consistent pattern of work. Some lenders want a longer history with the same employer or in the same industry.
Payslips, bank statements, tax returns
Overtime, bonuses, commissions
May be counted in full, at a reduced percentage, or not at all. A track record of receiving the income is often important.
Payslips, PAYG summaries, tax returns over a period
Self-employed or business owner
Usually based on documented business or taxable income over a period, sometimes averaged. A fall in recent income may be given weight.
Tax returns, notices of assessment, financials, BAS
Rental income
Often counted at a reduced percentage of the rent to allow for vacancy and costs, with the treatment set by the lender.
Lease or rental statements, property manager statements
Government payments and other regular income
Some may be accepted subject to conditions and how long they will continue. Treatment varies widely.
Statements or letters from the paying agency, bank statements
Investment income
May be accepted where it is regular and documented, often using an average over time.
Tax returns, dividend or interest statements
The practical point is that your “headline” income and your assessable income may not match. A borrower with significant variable income can find the gap between the two is large, and that gap differs between lenders.
Why Higher Income Does Not Always Mean a Bigger Loan
Income is only one side of the calculation. Several other factors can reduce what a lender may be willing to lend, even at a high income:
Living expenses: lenders assess your declared expenses against their own benchmarks and may use the higher figure.
Existing debts: car loans, personal loans, HELP repayments and other commitments reduce the surplus available.
Credit card limits: lenders generally consider the limit, not just the balance, so unused limits can still reduce capacity.
Dependants: children and other dependants can increase assessed expenses.
Deposit and loan-to-value ratio (LVR): a smaller deposit can limit options, and lenders mortgage insurance may apply above certain LVRs.
Loan type and term: interest-only loans, loan terms and the lender’s product rules can change the assessed repayment.
This is why two applicants earning the same amount can receive very different borrowing capacity estimates.
How Income Connects to the APRA Debt-to-Income Limit
Income also appears in APRA’s debt-to-income (DTI) measure, which compares relevant debt with gross annual income under APRA’s applicable reporting rules. APRA classifies a DTI ratio of six or more as high. From 1 February 2026, ADIs have been required to limit high-DTI lending to 20% of new owner-occupier mortgage lending and 20% of new investor mortgage lending, measured separately. These are limits on an ADI’s lending portfolio, not an individual borrower’s maximum borrowing limit or an automatic rejection threshold.
APRA’s DTI reporting measure covers relevant debt exposures under its reporting rules, including applicable mortgage and other credit commitments. HELP debt is excluded from APRA’s DTI reporting definition. However, compulsory HELP repayments may still affect a lender’s serviceability assessment because they reduce the income available for mortgage repayments. The treatment depends on the borrower’s circumstances and the lender’s policy.
In practice, the lower your assessable income is compared with your total debt limits, the higher your DTI and the more likely a high-DTI limit could become relevant to an ADI. Exempt loan types and lender discretion apply, so this is general information only.
Practical Australian Examples
These scenarios are hypothetical and simplified. They show the direction of the effect and do not predict what any lender will approve.
Example 1:
A salary with a bonus
An employee has a base salary of $100,000 and received a $15,000 bonus last year. One lender may count the base salary only. Another may count part of the bonus. A third may count most of it if the bonus has been paid consistently. Assessable income could therefore sit anywhere between $100,000 and $115,000 depending on the lender, which can lead to different borrowing capacity estimates.
Example 2:
Same income, different commitments
Two applicants each earn $120,000. One has no debts and a single credit card with a low limit. The other has a car loan, a personal loan and several credit cards with high limits. Even though the income is identical, the second applicant has less surplus after commitments, so a lender may assess a lower borrowing capacity.
Example 3:
A self-employed borrower
A sole trader’s taxable income was higher two years ago than in the most recent year. Some lenders may average the periods, while others may rely on the lower, more recent figure. The borrower’s assessable income, and so their borrowing capacity, could look quite different depending on which lender’s policy applies.
Example 4:
couple with one partner on reduced hours
A couple applies together. One partner has returned from leave and is working reduced hours. A lender may treat the current reduced income as the reliable figure, and some may ask for evidence of how long the arrangement will last. The household’s total assessable income may be lower than their combined full-time earnings.
What Documents Do Lenders Usually Ask For?
Requirements differ by lender and by income type. Documents commonly requested include:
Recent payslips and an employment letter or contract
PAYG payment summary or income statement
Personal and, for business owners, business tax returns and notices of assessment
Bank statements showing income and spending patterns
Rental statements or lease agreements for investment properties
Statements for existing loans and credit cards
Having these ready before you apply can make it easier for a lender to verify your income. Credit licensees have responsible-lending obligations under the National Consumer Credit Protection Act 2009. These include making reasonable inquiries about a consumer’s financial situation, requirements and objectives; taking reasonable steps to verify the consumer’s financial situation; and assessing whether the proposed credit contract would be unsuitable. The applicable obligations depend on the credit licensee’s role and the circumstances of the application.
Costs, Risks and Limitations maximum may be higher than what is comfortable on your household budget.
li>Income can change. A job change, reduced hours, a fall in business income or a rate rise can all affect your ability to keep up repayments.
Calculators are estimates. Online borrowing power tools use simplified assumptions and cannot replicate a lender’s full assessment.
Policies change. APRA settings and lender policies can change, so earlier results may not hold later.
Other costs apply. Stamp duty, lenders mortgage insurance, fees and ongoing costs sit outside your borrowing capacity but affect what you need.
VIP Finance operates as a Credit Representative (Number 565614) and holds ABN 59 323 956 021.
The information on this page is general in nature and doesn’t take into account your personal financial situation or objectives. It isn’t personal financial advice, and you should consider whether it’s appropriate for your circumstances before acting on it. Loan approval is always subject to the lender’s own credit assessment criteria.
Lenders count the income they can verify and consider reliable, subtract tax, living expenses and existing debts, and test whether what is left can cover new repayments at a buffered interest rate. More assessable income may increase capacity, but it does not guarantee an outcome.
Lenders usually start with gross income and then estimate tax to work out the income available for repayments. APRA’s separate DTI measure compares relevant debt with gross annual income.
It may be. Some lenders count it in full, some count a reduced portion and some exclude it. A consistent history of receiving it is often important.
Sometimes. Lenders commonly look at whether the overtime is regular and documented, and may count only part of it. Policies differ between lenders.
It can be possible. Lenders generally look for a consistent pattern of work and may ask for a longer employment history. Outcomes depend on the lender and the applicant’s circumstances.
Typically from tax returns and financials over a period, sometimes averaged. Recent income changes may be given weight, and documentation requirements vary.
Often, but lenders may count only a reduced percentage of the rent to allow for vacancy and costs. The percentage is set by each lender.
When you apply together, the lender generally assesses both incomes alongside both applicants’ expenses and debts. A co-borrower adds income but may also add commitments.
No. Expenses, debts, credit card limits, dependants, deposit and lender policy all affect the result, so higher income can still produce a modest borrowing capacity.
Yes, HELP debt may affect your borrowing capacity. Although HELP debt is excluded from APRA’s DTI reporting definition, compulsory HELP repayments may still affect a lender’s serviceability assessment by reducing the income available for mortgage repayments. The treatment depends on your circumstances and the lender’s policy.
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