If you receive an ATO tax bill that you cannot pay in full by the due date, you may be able to arrange instalments instead of paying the entire amount at once. This is where terms such as ATO payment plan and arrangement can become confusing. For individuals managing an income tax return in Perth, being aware of what these terms mean can help you choose a manageable way to clear what you owe. Before deciding how to manage a tax debt, let us see where that amount comes from and how Australian income tax is calculated.
Australian income tax is generally calculated on your taxable income, which is your assessable income after eligible deductions. The amount you pay depends on the applicable tax rates, tax offsets and other factors such as the Medicare levy.
Taxable income is the amount of income the ATO uses to calculate your income tax liability. It is generally your assessable income after subtracting eligible deductions.
For the 2026–27 income year, Australian residents who are entitled to the full tax-free threshold are taxed progressively, meaning different portions of taxable income fall into different tax brackets. The rates below do not consider the Medicare levy, which is an additional 2%.
| Taxable income | Tax on this income |
| $0 – $18,200 | Nil |
| $18,201 – $45,000 | 15c for each $1 over $18,200 |
| $45,001 – $135,000 | $4,020 + 30c for each $1 over $45,000 |
| $135,001 – $190,000 | $31,020 + 37c for each $1 over $135,000 |
| $190,001 and over | $51,370 + 45c for each $1 over $190,000 |
A personal tax accountant can help you navigate these figures with ease.
Calculating taxable income starts with identifying your assessable income and then deducting eligible expenses. The amount left after these deductions is generally the figure used to work out your income tax.
The basic calculation is:
The resulting amount is then used to determine the applicable tax under Australia’s progressive tax rates.
To calculate income tax, first determine your taxable income and then apply the tax rates for the relevant income year.
Suppose an Australian resident has $42,000 in taxable income for 2026–27.
The first $18,200 is not taxed. The remaining $23,800 falls within the $18,201 to $45,000 bracket, which is taxed at 15 cents for each dollar over $18,200.
So:
$42,000 − $18,200 = $23,800
$23,800 × 15% = $3,570
Therefore, the income tax calculated on $42,000 of taxable income is $3,570, before considering the Medicare levy, tax offsets or other applicable adjustments.
Your final tax payable depends on the tax calculated on your taxable income, less eligible offsets and credits such as PAYG withholding. Other amounts, including the Medicare levy or HELP repayments, may then be added.
PAYG withholding is the tax your employer or another payer has already deducted from your income and paid towards your tax liability.
Tax offsets can reduce the tax calculated on your taxable income, while the Medicare levy is generally added as a separate liability.
Understanding your tax liability involves more than applying the relevant tax rates. Your income, eligible deductions and tax credits can all affect the final amount payable. Palladium Financial Group provides accounting and taxation support for individuals and businesses across Perth, helping them understand their tax obligations and manage their financial records
A tax refund generally arises when the tax already paid during the year is more than your final tax liability. Your refund can change after deductions, offsets, credits and other liabilities are taken into account.
Eligible deductions can reduce your taxable income by lowering the amount of assessable income on which tax is calculated. The deduction must generally be allowable under tax rules and supported by appropriate records.
Deductions can cover expenses you incur while earning your income, as long as they meet the relevant eligibility requirements.
Work-related expenses may be deductible when they relate directly to earning your income, and you meet the ATO’s requirements.
Other deductible expenses can include eligible gifts and donations or certain costs associated with managing your tax affairs. The actual deduction depends on your circumstances and the relevant tax rules.
Professional tax accounting can help you identify eligible deductions and include them correctly in your tax return.
The way income is treated for tax purposes depends on where it comes from and how it is reported. Generally, you are required to include all relevant income while calculating your taxable income, then subtract eligible deductions.
Your employer may withhold tax through PAYG, which is later credited against your tax liability.
Business or sole trader income is included when calculating taxable income, with allowable business expenses potentially reducing the amount subject to tax.
Rental income, interest, dividends and managed fund or trust distributions can form part of your income. Alongside, capital gains or losses may need to be considered when preparing your tax return.
You get an estimate of your potential tax refund or amount payable through this calculator based on the information you enter. These insights can be used for planning, but they are not a replacement for your final ATO assessment.
A tool like this can estimate your taxable income, tax liability, potential refund or amount payable using the information available. Alongside, you are presented with a clear picture of how deductions, offsets and PAYG withholding can affect your overall tax position.
The ultimate outcome can differ because the ATO can receive updated pre-fill information or identify differences through data matching. Moreover, existing credits or debts may affect the amount you ultimately receive or owe.
Hence, your final notice of assessment provides the official outcome after the ATO processes your return. In such circumstances, an income tax return service can make sure that the information used in your return is complete and reported accurately.
Tax calculations can be erroneous when you use the wrong income figure or overlook deductions and tax credits.
Taxable income is often calculated after subtracting eligible deductions from your assessable income, not always the gross income.
Failing to claim eligible deductions can increase your taxable income unnecessarily. Work-related expenses and other allowable expenses can minimise the amount on which your tax is calculated.
PAYG withholding is tax that has already been paid towards your liability but not always your final tax bill. Your final result accounts for taxable income, offsets, other liabilities and available credits.
For better tax accounting in Perth, you can consult experts to identify these issues and ensure the relevant information is reported properly.
Also read: How We Helped a Client Manage an ATO Tax Debt Before It Escalated
Accurate calculation of your Australian tax needs knowledge of your taxable income, eligible deductions, tax brackets, PAYG amounts and applicable offsets. This is when a tax calculator can give a useful estimate, but your final outcome will still be based on the information in your return and the ATO’s assessment. If you need help reviewing your tax position or lodging accurately, professional tax return services in Perth can make the entire procedure more organised and efficient.
To calculate income tax in Australia, first subtract eligible deductions from your assessable income to determine your taxable income. Apply the relevant income tax rates for the financial year, then account for tax offsets, the Medicare levy and other applicable amounts. Finally, subtract PAYG withholding and eligible credits to estimate whether you will receive a refund or have tax to pay.
Your taxable income is generally calculated by subtracting allowable deductions from your assessable income. For example, if your assessable income is $60,000 and you have $5,000 in eligible deductions, your taxable income would be $55,000.
For Australian resident individuals entitled to the full tax-free threshold, the 2026–27 tax rates are:
$0–$18,200: 0%
$18,201–$45,000: 15%
$45,001–$135,000: 30%
$135,001–$190,000: 37%
Over $190,000: 45%
These rates exclude the Medicare levy and other applicable adjustments.
Your tax refund depends on the tax you have already paid compared with your final tax liability. If your PAYG withholding and eligible credits exceed the amount you owe, you may receive a refund. Deductions, tax offsets, student loan repayments and outstanding government debts can affect the final amount.
Yes. An Australian tax calculator can estimate your income tax, potential refund or amount payable using details such as your taxable income, deductions and tax withheld. However, the result is only an estimate and may differ from your final ATO notice of assessment.
Gross income generally refers to income before deductions, while taxable income is generally your assessable income less allowable deductions. Tax is calculated using your taxable income rather than simply applying the tax rates to your gross salary.
Your refund may be lower than expected because of additional tax liabilities, Medicare levy adjustments, HELP repayments, changes to eligible deductions or offsets, or outstanding debts that the ATO may offset against your refund.
Eligible work-related expenses, certain donations and other allowable expenses may reduce your taxable income. You must meet the relevant ATO requirements, and some expenses require supporting records. The deductions available depend on your individual circumstances.
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