Most people assume that the ATO taxes everything you earn. But what if you spent $800 on work boots, $1,200 on a professional development course, and donated $500 to a registered charity? The tax system allows you to subtract certain work-related costs from your income before tax is calculated — meaning you pay tax on less. This is called a deduction, and knowing what qualifies is worth real money. Before we do the maths, think: what kinds of expenses do you think should count as tax deductions, and why?
Type your initial response below — you will revisit this at the end of the lesson.
Write your initial response in your book. You will revisit it at the end of the lesson.
All assessable income sources — wages, bank interest, rental income, certain government payments
$\text{Allowable deductions} = \text{Sum of all eligible work-related and approved expenses}$
Must be directly incurred in earning income — personal expenses do not qualify
Reverse formula: $\text{Allowable deductions} = \text{Gross income} - \text{Taxable income}$ (use when taxable income is given)
Know
The formula: taxable income = gross income − allowable deductions
That gross income includes all assessable income (salary, interest, rental income)
Examples of allowable and non-allowable deductions
Understand
Why tax is applied to taxable income, not gross income
Why not all expenses qualify as deductions (personal vs income-earning)
Why PAYG tax withheld is not an allowable deduction
Can Do
Identify which items in a list are allowable deductions
Calculate gross income from multiple sources
Calculate taxable income and work backwards from taxable income to find deductions
Misconceptions to Fix
✗
Wrong: Taxable income is the same as gross income.
✗
Right: Taxable income = gross income minus allowable deductions (work-related expenses, donations, etc.). You only pay tax on taxable income.
Core Content
Key Terms
Taxable IncomeGross income minus allowable deductions — the amount on which tax is calculated.
Gross IncomeTotal income from all sources before any deductions.
Allowable DeductionWork-related expenses that can be subtracted from gross income to reduce taxable income.
Tax OffsetA reduction in the amount of tax payable, also called a tax rebate.
Medicare LevyA 2% levy on taxable income to fund the public health system.
Gross Income vs Taxable Income
Gross income is everything you earn; taxable income is the smaller figure the ATO actually uses to calculate your tax bill.
Gross income includes your salary or wages, interest earned on bank accounts, rental income from investment properties, and certain government payments. It is the total of all assessable income before any deductions.
Taxable income is gross income minus allowable deductions. The distinction matters because income tax is calculated on taxable income, not gross income. Reducing your taxable income — legally, through legitimate deductions — reduces the tax you owe.
Deductions reduce taxable income, which directly reduces the tax bill.
Tax is calculated on taxable income, not gross income: Always complete the taxable income calculation before attempting any tax calculation. Applying tax brackets to gross income is a guaranteed error.
Common error — Not all expenses are deductions: Only expenses directly related to earning income and not reimbursed by the employer qualify. Personal expenses — gym memberships, groceries, commuting to your regular workplace — are not deductible, even if they feel work-related.
Allowable Deductions — What Qualifies?
The ATO has specific rules about what counts as a deduction — the general principle is that the expense must be directly incurred in earning your assessable income.
Allowable ✓
Not allowable ✗
Work tools and equipment
Travel from home to regular workplace
Uniforms and protective clothing
Conventional clothing worn at work
Professional development courses
Personal grooming and gym memberships
Work-related textbooks and resources
Private or domestic expenses
Union fees and professional memberships
Meals (unless travelling overnight for work)
Donations to registered DGRs ($2+)
Donations to unregistered causes
Home office expenses (if required)
General home expenses
List the allowable deductions first, then total them: Don't try to identify and add simultaneously. Write each qualifying deduction with its amount, then sum — this earns method marks and prevents omissions.
Common error — Donations only qualify if made to a registered DGR: Giving money to a friend's fundraiser does not qualify. HSC questions will state "registered charity" or "deductible gift recipient" when a donation qualifies. If it just says "donation" with no further detail, treat it as non-deductible unless clarified.
Insight — The general principle: An expense is deductible if it is incurred in gaining or producing assessable income and is not private, domestic, or capital in nature. This principle helps you reason through unfamiliar cases in the exam — ask: "Did the worker need to spend this money specifically because of their job?"
Calculating Taxable Income — Full Process
Taxable income calculation follows a fixed sequence: identify all income sources, identify all allowable deductions, then subtract.
Step
Action
1
List all income sources and sum to get gross income
2
Go through each listed expense and determine if it is allowable
3
Sum only the allowable deductions
4
Taxable income = Gross income − Total allowable deductions
5
Label taxable income clearly before moving to any tax calculation
In HSC extended response questions, part (a) often asks for taxable income, and parts (b) and (c) build on that figure. An error in part (a) flows through the entire question — but markers will still award marks in later parts if you use your part (a) answer consistently.
Show the subtraction explicitly: Write "Taxable income = $X − $Y = $Z" as a standalone line. Don't bury it in a calculation chain — it needs to be clearly identifiable for the marker.
Common error — Don't include PAYG tax withheld as a deduction: PAYG tax is not an allowable deduction from income. It is a prepayment of tax — it reduces your tax bill at the end of the year, but it is not subtracted when calculating taxable income. Confusing this costs marks.
A Quick Filter for Testing Deductions
When a question gives a long list of expenses, the fastest reliable method is to test each one against a simple decision rule.
Ask three questions:
Was the expense incurred in earning assessable income?
Was it private or domestic in nature?
Was the worker reimbursed for it?
If the answer to the first question is yes and the second and third are no, the expense is usually deductible in this level of HSC-style problem.
Exam technique: Put a quick tick or cross beside each listed expense before you total anything. This helps prevent you from accidentally including a non-deductible item in the final subtraction.
Reasonableness check: Taxable income should be lower than gross income, but not dramatically lower unless the deductions list is very large. If your deductions look suspiciously huge, review which items you included.
Worked Examples
Worked Example 1Identifying Deductions
Problem
Sophie is a secondary school teacher. Her annual salary is $89,400. She also earned $640 interest on a savings account. During the year she spent: $480 on textbooks and classroom resources, $320 on a professional development course, $180 on a conventional work wardrobe, $250 donation to a registered charity, $860 on daily train travel to school. Calculate her taxable income.
Solution
1$\text{Gross income} = \$89{,}400 + \$640 = \$90{,}040$Salary plus bank interest — both are assessable income
3$\text{Conventional wardrobe: } \$180 \times \quad \text{Train travel to school: } \$860 \times$Conventional clothing and ordinary commuting are NOT deductible
4$\text{Total allowable deductions} = \$480 + \$320 + \$250 = \$1{,}050$Sum only the qualifying items
5$\text{Taxable income} = \$90{,}040 - \$1{,}050 = \$88{,}990$Gross income minus allowable deductions
Worked Example 2Multiple Income Sources
Problem
David earns a salary of $74,200, receives $1,850 in rental income from an investment property, and earned $420 in bank interest. His allowable deductions total $3,640. Calculate his taxable income.
Solution
1$\text{Gross income} = \$74{,}200 + \$1{,}850 + \$420 = \$76{,}470$Sum all three assessable income sources
2$\text{Total allowable deductions} = \$3{,}640$Given directly in this question — no identification step needed
3$\text{Taxable income} = \$76{,}470 - \$3{,}640 = \$72{,}830$Gross income minus allowable deductions
Worked Example 3Working Backwards
Problem
Anika's taxable income is $61,450. Her gross salary is $64,800 and she earned $380 in interest. What were her total allowable deductions?
2$\text{Deductions} = \text{Gross income} - \text{Taxable income} = \$65{,}180 - \$61{,}450 = \$3{,}730$Rearrange the taxable income formula to find deductions
3$\text{Check: } \$65{,}180 - \$3{,}730 = \$61{,}450 \checkmark$Verify by working forward — taxable income matches
Worked Example 4Mixed Deduction List
Problem
Olivia earned $72,400 in salary and $560 in bank interest. Her listed expenses are: $420 union fees, $660 professional registration, $240 conventional business clothes, $1,150 commuting costs, and a $300 donation to a registered charity. Calculate her taxable income.
Solution
1$\text{Gross income} = \$72{,}400 + \$560 = \$72{,}960$Salary plus interest
2\text{Allowable: union fees } \$420,\; \text{professional registration } \$660,\; \text{registered charity donation } \$300These are deductible in this context
3\text{Not allowable: conventional clothes } \$240,\; \text{commuting costs } \$1{,}150These are private or ordinary commuting expenses
4\text{Total allowable deductions} = \$420 + \$660 + \$300 = \$1{,}380Sum only the allowable items
5\text{Taxable income} = \$72{,}960 - \$1{,}380 = \$71{,}580Gross income minus allowable deductions
Revisit Your Initial Thinking
Look back at what you wrote in the Think First section. What has changed? What did you get right? What surprised you?
Check Your Understanding
Checkpoint Questions
Select the best answer for each question. Feedback appears after you choose.
MC
Multiple Choice
5 random questions from a replayable lesson bank — feedback shown immediately
B) $57,780
C) $56,860
D) $58,920
A is correct. Gross income = $58,000 + $920 = $58,920. Taxable income = $58,920 − $2,140 = $56,780. Option B omits bank interest from gross income; C subtracts deductions from salary only; D is gross income with no deductions applied.
Which of the following is an allowable tax deduction?
A) Daily train fare from home to a regular office
B) Gym membership to stay fit for a physical job
C) Union membership fees
D) Conventional business attire purchased for work
C is correct. Union fees are specifically allowable. Commuting (A), gym memberships (B), and conventional clothing (D) are all non-deductible personal expenses regardless of whether they relate to work.
A worker's taxable income is $83,200. Their gross salary is $86,500 and they received $750 in interest. What were their total allowable deductions?
A) $3,300
B) $4,050
C) $3,750
D) $2,550
B is correct. Gross income = $86,500 + $750 = $87,250. Deductions = $87,250 − $83,200 = $4,050. Option A ignores interest income (uses salary only); C subtracts from salary only; D is an arithmetic error.
Which item should NOT be counted as an allowable deduction in a standard HSC-style tax question?
A) Union fees
B) Work-related textbooks
C) Donation to a registered charity
D) PAYG tax withheld
D is correct. PAYG tax withheld is not an allowable deduction from income; it is a prepayment toward the worker's tax bill.
Written Response Practice
These questions focus on classifying deductions accurately before doing the subtraction.
Short Answer 1
A worker earns $64,500 in salary and $700 in bank interest. Their allowable deductions total $2,850. Calculate their taxable income.
Gross income: $64,500 + $700 = $65,200
Taxable income: $65,200 - $2,850 = $62,350
Short Answer 2
A worker's taxable income is $58,900. Their salary is $61,200 and they earned $300 in interest. Calculate their total allowable deductions.
Gross income: $61,200 + $300 = $61,500
Allowable deductions: $61,500 - $58,900 = $2,600
Short Answer 3
A worker earns $78,000 salary. Their listed expenses are $520 union fees, $860 commuting costs, $290 donation to a registered charity, and $430 work-related textbooks. Calculate their taxable income.