Tax deductions in Australia let you reduce your taxable income by claiming legitimate business expenses against your earnings. The Australian Taxation Office (ATO) allows deductions on expenses that are directly related to earning your income, but the rules around what qualifies, how to record it, and when to claim it trip up thousands of small business owners every year. This comprehensive guide walks through the core categories, common mistakes, and the records you need to keep.
What makes an expense tax-deductible?
The ATO applies a straightforward test: the expense must be incurred in the course of producing assessable income, and it must not be a private or domestic expense. Three conditions must hold at once. The expense must be genuine (you actually paid it). It must be directly connected to your business activity. And you must have a record to prove it.
A plumber buying copper fittings for a job clears all three. The same plumber buying a kitchen tap for their home does not. The line between business and private spending is where most disputes with the ATO originate, so it's worth being precise from the start rather than relying on vague recollections at tax time.
Common categories of deductible expenses
Most deductible expenses fall into a handful of categories that apply across industries. The specifics vary by trade, profession, and business structure, but the logic is consistent.
Operating expenses
Day-to-day costs of running the business are generally deductible in the income year you incur them. This includes rent for business premises, utilities used at those premises, office supplies, software subscriptions, professional memberships, and advertising costs. If you use a co-working space or pay for a business phone plan, those costs qualify too. Keep the invoices.
Vehicle and travel expenses
Business-related travel is deductible. Commuting from home to a fixed place of work is not. The distinction matters enormously for sole traders who work from different job sites each day versus those who drive to the same office every morning.
For vehicles, the ATO offers two methods: the cents per kilometre method (68 cents per kilometre in the 2024–25 income year, capped at 5,000 km) and the logbook method, which captures actual costs based on documented business-use percentage. The logbook method usually yields a higher deduction for high-mileage workers, but it requires 12 weeks of contemporaneous records.
Home office expenses
Sole traders and employees working from home can claim home office running costs. The ATO's revised fixed-rate method allows 70 cents per hour for every hour worked from home, covering electricity, internet, phone, and stationery. Alternatively, the actual cost method lets you claim the precise proportion of home expenses attributable to your work area, but it requires calculating the floor-area percentage and keeping detailed records.
You can't claim a deduction for mortgage interest or rent on a home office using the fixed-rate method. That's only available under the actual cost method, and only on the business-use proportion.
Equipment and depreciation
Assets with a cost above the instant asset write-off threshold are depreciated over their effective life rather than deducted in full immediately. The instant asset write-off threshold has moved around in recent years, so check the ATO's current guidance before assuming a large purchase qualifies for an immediate deduction. For eligible small businesses, the threshold has been as high as $150,000 in recent income years.
Assets below the threshold can be written off in the year of purchase. Assets above it enter the small business depreciation pool, where they're depreciated at 15% in the first year and 30% thereafter.
Professional development and education
Training, courses, and conferences that directly relate to your current work are deductible. A graphic designer paying for an advanced Adobe course qualifies. The same designer paying for a real estate licence course does not, because it's for a different field entirely. The expense must maintain or improve skills relevant to the income you're already earning, not open a new career path.
Insurance premiums
Business insurance premiums are deductible. Public liability insurance, professional indemnity insurance, and tool insurance all qualify as legitimate business expenses. If you're launching a gym in Australia or any other customer-facing business, insurance is both a legal necessity and a tax-deductible one.
Accounting and legal fees
Fees paid to a registered tax agent for preparing your business tax return are deductible. So are fees for bookkeeping, legal advice on a business matter, and the cost of using accounting software like Xero or MYOB. Personal legal costs (such as a family law dispute) are not deductible, even if they happen to involve a business asset.
Sole traders vs companies: different rules apply
The categories above apply broadly, but the way deductions flow through depends on your business structure. Sole traders report business income and deductions on their individual tax return. The net profit is taxed at their marginal rate. Companies file a separate company tax return and pay the company tax rate (25% for base rate entities with turnover under $50 million in 2025–26). The deduction categories are similar, but the treatment of owner drawings, superannuation contributions, and Division 7A loans differs meaningfully. If you're running multiple businesses under one company, the interaction between entities adds another layer of complexity worth discussing with an accountant.
What you can't claim
Some expenses look business-related but don't pass the ATO's test. Private expenses disguised as business costs are the most common audit trigger. Specific items the ATO disallows include:
- Traffic fines, even if incurred while driving for work
- Private health insurance premiums (these go through the Medicare Levy Surcharge system, not as a business deduction)
- Clothing that isn't a protective uniform or occupation-specific (plain suits don't qualify)
- Entertainment expenses where the primary purpose is enjoyment rather than business
- Capital expenditure on assets above the instant asset write-off threshold (these must be depreciated, not deducted in full)
Record-keeping: the part most people underestimate
The ATO requires you to keep records for five years from the date you lodge the relevant tax return. Records must show the amount, the date, who you paid, and the business purpose. Bank statements alone don't always satisfy this. Receipts, invoices, contracts, and logbooks are what the ATO actually wants to see in an audit.
Cloud-based bookkeeping tools make this easier than it used to be. Photographing receipts at point of purchase and attaching them to transactions in real time takes seconds and saves significant stress later. The ATO's own records guidance is detailed and worth reading once a year.
Timing: when to claim
Most expenses are claimed in the income year they're incurred, which in Australia runs from 1 July to 30 June. "Incurred" means when the liability arose, not necessarily when you paid the invoice. Pre-paying expenses for the following year is only deductible in limited circumstances, primarily for individuals and small businesses paying for a period of 12 months or less that ends in the next income year.
If you're unsure whether a large, unusual expense should be claimed now or spread across years, a registered tax agent can tell you in 15 minutes and the fee for that advice is itself deductible.
Getting help with your tax deductions
The ATO publishes detailed occupation and industry-specific guides on its website that list the deductions most commonly claimed in each field. These are worth reading before you prepare your return. A registered tax agent adds value beyond what those guides cover, particularly for complex situations involving vehicle fleets, home office calculations, or mixed-use assets.
Tax deductions in Australia aren't a shortcut or a grey area. Claimed correctly with proper records, they're a legitimate mechanism for reducing the tax you pay on the income you actually earn from your business.