Australian small businesses can claim deductions for expenses that are directly related to earning assessable income. The ATO requires that you have records (receipts, invoices, or bank statements) for every claim and that the expense has a clear business purpose.
Common deductions include: motor vehicle expenses (logbook or cents-per-kilometre method), home office running costs (fixed-rate at 67 cents per hour, or actual cost method), phone and internet (business-use percentage), tools and equipment under the instant asset write-off threshold, professional development and training, insurance premiums (public liability, professional indemnity, income protection), accounting and tax agent fees, and advertising and marketing costs.
The instant asset write-off allows eligible businesses with aggregated turnover under $10 million to immediately deduct the full cost of eligible assets costing less than $20,000 each (threshold as of 2025-26 — check ato.gov.au for current limits as this changes frequently). Assets above the threshold are added to the small business simplified depreciation pool.
One of the most common mistakes is claiming private expenses as business deductions. The ATO uses data matching and benchmarking to flag businesses with unusually high deduction-to-income ratios. If an expense is partly personal (like a phone or car), you can only claim the business-use portion.