Business Tax Deductions in Australia: What to Track and Claim (2025-26)

Every dollar you spend running your business that qualifies as a tax deduction reduces your taxable income and therefore your tax bill. For an Australian small business paying a 25% company tax rate, a legitimate $10,000 deduction is worth $2,500 in tax savings. At a 37% marginal rate for a sole trader, it is worth $3,700.

The challenge is not knowing deductions exist. Most business owners know they can claim rent, wages, and software subscriptions. The challenge is tracking expenses correctly as they occur so that when your accountant asks for records in June, you have everything substantiated and coded. The ATO’s primary reason for disallowing legitimate deductions is not that the expense was ineligible, but that the taxpayer could not prove they incurred it.

This guide covers the three golden rules for Australian business deductions, which expenses you can and cannot claim in 2025-26, how to build a tracking system that satisfies ATO substantiation requirements, and the key 2025-26 changes you need to know. For personalised deduction advice specific to your business, see our small business tax return service.

The Three Golden Rules for Australian Business Tax Deductions

The ATO summarises the conditions for claiming a business deduction in three rules. Every expense you claim must pass all three. These come from the ATO’s business deductions guidance:

Rule 1: The expense must be for business purposes. This means the expense must be incurred in the course of earning your business income. The ATO uses a ‘sufficiently connected’ test: is this expense connected to how you earn income from your business? Expenses that are incidental, speculative, or personal do not meet this test.

Rule 2: You must have actually incurred the expense. You cannot deduct money you have not spent. An intention to spend, or an estimate of future spending, does not create a deduction. You must have been legally liable for the expense and it must have been incurred in the tax year you are claiming it.

Rule 3: The expense must not be private, domestic, or capital in nature. Personal living costs are not business deductions. The family grocery bill remains personal even if you discuss business at dinner. Capital expenses (building or buying assets) are treated differently from operating expenses and must be depreciated over the asset’s effective life, unless the instant asset write-off applies.

When an expense has both business and private components, you can only deduct the business portion. A phone used 70% for business allows a 70% deduction. You must be able to demonstrate and document the apportionment methodology.

What Business Expenses Are Tax Deductible in Australia? (2025-26)

What You Cannot Claim as a Business Expense

The $20,000 Instant Asset Write-Off

The instant asset write-off allows eligible small businesses to deduct the full cost of eligible depreciating assets in the year the asset is first used or installed ready for use, rather than depreciating it over its effective life.

2025-26 rules:

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  Threshold: $20,000 per asset. Assets costing $20,000 or more must use the small business pool depreciation rules.
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  Eligibility: you must be a small business entity (annual aggregated turnover under $10 million). The asset must be used for business purposes.
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  Deadline: the asset must be first used or installed ready for use by 30 June 2026. Simply purchasing and not installing by 30 June does not qualify for the 2025-26 year.
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  Both new and second-hand assets: the write-off applies to both new and second-hand assets in most cases.

Important: the $20,000 instant asset write-off is a business deduction, not an individual employee deduction. It applies to assets your business buys for business purposes. An individual employee buying their own tools has a separate $300 per-item threshold.

What Is the $1,000 Instant Tax Deduction?

From 2026-27 onwards, employed individuals can claim $1,000 in work-related deductions without keeping receipts. If their actual work-related expenses exceed $1,000, they claim the higher actual amount with records. This does not change how Australian businesses claim deductions. Business expenses are still claimed under the three-golden-rules framework with appropriate substantiation.

How to Track Business Expenses Correctly for ATO Substantiation

The ATO requires that deductions be substantiated with written evidence when total work-related or business expense claims exceed $300. For business expenses, the default expectation is that you hold a valid tax invoice for every purchase: a document that includes the supplier’s name, ABN, date of the supply, description of goods or services, the price, and the amount of GST if applicable.

Step 1: Open a Dedicated Business Bank Account and Card

Every business transaction should flow through a dedicated business account and business credit card. This creates a clean, complete record of all business spending and eliminates the need to sort personal from business expenses at tax time. For companies (Pty Ltd), keeping business and personal finances separate is a legal requirement - company money cannot be used for personal expenses without proper documentation (typically a loan or dividend arrangement that may trigger tax consequences).

Step 2: Connect Bank Feeds to Cloud Accounting Software

Xero, MYOB, and QuickBooks Online Australia all connect directly to major Australian banks via bank feeds, importing transactions daily. Each transaction is automatically available to code to the correct expense category and GST treatment. This creates a contemporaneous, ATO-compliant record without manual data entry. The Kalculators are Xero Gold Partners and can set up and configure bank feeds and expense categories as part of our bookkeeping setup service.

Step 3: Capture Every Receipt Digitally at the Point of Purchase

Use a document capture app (Dext, Hubdoc, or your accounting software’s mobile app) to photograph every receipt immediately after purchase. The app reads the supplier, amount, date, and GST, and creates a digital record linked to the transaction in your accounting software. Digital records are fully accepted by the ATO and satisfy the written evidence requirement. You do not need to keep paper originals if you have a complete, legible digital copy.

Step 4: Code Each Expense to the Correct Category and GST Treatment

Every business expense needs to be assigned to the correct account in your chart of accounts (rent, wages, motor vehicle, marketing, etc.) and coded with the correct GST treatment (taxable, GST-free, or out of scope). Correct coding is what connects your expense records to your BAS and income tax return. Miscoded expenses either understate or overstate your GST credits and may cause your deductions to be challenged.

Step 5: Reconcile Monthly and Review Quarterly

Reconcile all bank accounts and credit cards at month-end to confirm every transaction is recorded and coded. Before each quarterly BAS, review your expense categories to ensure deductions are being captured correctly. Before 30 June, review with your accountant for any year-end planning: prepaying deductible expenses, purchasing assets under the instant write-off, or making super contributions before the financial year closes.

Step 6: Keep Records for 5 Years

The ATO requires most business expense records to be kept for 5 years from the date you lodge your tax return for the relevant year. Payroll and employment records require 7 years under the Fair Work Act. CGT-related records (assets you might sell) must be kept for 5 years after disposal. Cloud accounting software retains records indefinitely and satisfies this requirement automatically. See the ATO’s record-keeping requirements for businesses for the full schedule.

Common Business Expense Tracking Mistakes That Cost Australian Businesses

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  Mixing personal and business spending: using the business card for personal expenses or paying business costs from the personal account creates untraceable transactions, inflated deductions, and an ATO audit risk.
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  Claiming 100% of mixed-use expenses: a phone used 40% personally can only be deducted at 60%. A car used for personal travel on weekends cannot be fully deducted through a logbook that only reflects business days.
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  Claiming the ATO $300 threshold incorrectly: the $300 per-item threshold means individual items under $300 can be deducted without a receipt. It does not mean you can claim $299 of total expenses without any records. If your total business expense claims exceed $300, the ATO requires substantiation for all claims.
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  Not keeping records because 'the bank statement is enough': a bank statement shows money left your account. It does not show what you bought, whether it was for business, or the GST amount. A valid tax invoice is required for GST credit claims over $82.50.
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  Deducting expenses in the wrong year: under accrual accounting, expenses are deductible when incurred, not when paid. Under cash accounting, they are deductible when paid. Claiming a 2024-25 invoice in 2025-26 (or vice versa) is an error that affects both your BAS and your income tax return.
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  Forgetting to claim the prior year’s tax agent fee: the fee you paid your accountant or BAS agent for the previous year’s return is deductible in the current year. This is consistently overlooked and is a straightforward deduction to claim.

How The Kalculators Can Help Maximise Your Business Deductions

Our small business tax return service includes a systematic review of your expenses to ensure every legitimate deduction is claimed. We work from your accounting records (Xero, MYOB, or whatever system you use) and identify deductions that are commonly missed, correctly apply the instant asset write-off where available, and ensure your expense coding is consistent with your BAS lodgments.

If you have already lodged and believe you may have missed deductions, our second look tax assessment service reviews your return and lodges an amendment to recover any amounts left on the table.

For ongoing expense tracking, our bookkeeping team in Adelaide can set up your chart of accounts, configure Xero or MYOB, and handle monthly reconciliation so your records are always ATO-ready. Our business advisory services provide year-end tax planning to ensure major spending decisions are timed to maximise deductibility.

Call (08) 7480 2593, Monday to Friday, 9:00 AM to 6:00 PM. Offices at 182 Salisbury Highway, Salisbury; 315 Prospect Road, Blair Athol; and 280 Main South Road, Morphett Vale. Online services for Murray Bridge, Woodville, Melrose Park, Port Augusta, Prospect, and Brighton via info@thekalculators.com.au.