8 Commonly Missed Tax Deductions for Australian Business Owners

Last Updated July 2026

Claiming every tax deduction you're entitled to can significantly reduce your tax bill, yet many Australian business owners miss legitimate business tax deductions every year. Whether you're a sole trader, company or trust, understanding what you can claim—and keeping the right records—can help you avoid paying more tax than necessary.

At L & Co, we regularly review accounting files and tax returns for Australian business owners and often identify deductions that have been overlooked simply because the records weren't kept or the business owner didn't realise the expense was deductible. Here are eight of the most commonly missed tax deductions we see Australian business owners overlook.

1. Home Office Expenses
   

   If you do any work from home — even part-time, even just admin and invoicing — you may be able to claim a portion of your home running costs: electricity, internet, phone, and depreciation on office furniture or equipment. Many business owners either don't claim this at all, or under-claim because they're not tracking hours worked from home properly. Depending on your circumstances, you may be able to use the ATO's fixed-rate method or claim actual running expenses, provided you meet the record-keeping requirements.

   
   

   Tip: the ATO requires a record of hours worked from home (a diary, logbook, or timesheet) to substantiate this claim — it's worth setting up a simple system now rather than trying to reconstruct it at tax time.

2. Vehicle and Travel Expenses Business-related car use is deductible, but it's commonly under-claimed because business owners don't keep a logbook or don't realise trips beyond the obvious ones (client meetings, supplier pickups) also count — think trips to the accountant, the bank for business purposes, or between multiple work sites.

   
   

   For many business owners using the logbook method and keeping a valid 12-week logbook can result in substantially larger deductions than relying on the cents-per-kilometre method.

3. Professional Development and Education Courses, conferences, subscriptions, and industry memberships that relate to your current business activities are generally deductible — but this category gets missed constantly because it doesn't feel like a "business expense" in the way stock or rent does.This includes online courses, industry publications, professional association fees, and even some conference travel costs.
   

4. Bad Debts If a client hasn't paid an invoice and you've genuinely written it off as uncollectable, that amount can generally be claimed as a bad debt deduction — but only if you've formally written it off in your accounts before the end of the financial year. A lot of business owners simply stop chasing an unpaid invoice without formally writing it off, which means the deduction is missed entirely.
   

5. Prepaid Expenses Small business entities can immediately deduct certain expenses prepaid up to 12 months in advance, rather than spreading the deduction across the period the payment actually covers. This is a genuine EOFY tax planning lever — not just a "don't forget to claim it" item.
   

   For example: if you pay your business insurance, a software subscription, or a professional membership renewal in June for the 12 months ahead, the entire amount can often be claimed in the current financial year rather than split across two. For a business trying to bring forward deductions in a strong income year, this is one of the more useful (and most overlooked) timing strategies available.
   

6. Trading Stock Write-Offs Businesses carrying stock are required to do a stocktake and value it at year-end — but most owners default to valuing everything at cost, without realising the ATO allows three valuation methods per item: cost, market selling value, or replacement value. You can pick whichever is lowest for each item, which is a legitimate way to reduce taxable income on stock that's slow-moving, damaged, or out of season.

   
   

   Genuinely obsolete or unsellable stock can be written down to its real value — or written off entirely if it's worthless — but this only counts if it's backed by an actual stocktake and proper documentation, not just an estimate at tax time.
   

7. Repairs and Maintenance vs Capital Improvements Genuine repairs (restoring something to its original condition — fixing a leaking roof, repairing equipment) are immediately deductible in full. Capital improvements (extending or upgrading beyond original condition) have to be depreciated over time instead. A lot of business owners either misclassify a genuine repair as a capital cost and lose the immediate deduction, or don't realise the distinction exists at all and just lump everything under "repairs" without checking. Sometimes a single invoice includes both repairs and capital improvements, so it's worth separating the costs where possible rather than treating the entire amount as capital.
   

8. Client Gifts (Non-Entertainment)

   Client entertainment — meals, tickets, functions — is largely not deductible. But genuine gifts that don't count as entertainment (a gift hamper, flowers or a gift voucher sent as a thank-you) generally are fully deductible. Business owners often either wrongly claim entertainment costs that aren't allowed, or swing the other way and don't claim legitimate gifts because they've bundled the whole category together as "probably not deductible."

Why These Deductions are Missed

Most missed deductions come down to one of two things: not knowing the expense qualifies, or not having the records to back it up if it does. The ATO requires deductions to be substantiated — a bank statement alone often isn't enough if it's audited, particularly for things like home office use and vehicle expenses.

The fix isn't complicated, but it does need to happen throughout the year rather than in a scramble at tax time: keep receipts, log business kilometres as you go, and flag anything you're unsure about with your accountant rather than assuming it's not claimable.

Missing legitimate tax deductions doesn't just mean paying more tax—it can also affect your business cash flow. The best approach is to keep accurate records throughout the year, ask questions when you're unsure, and review your deductions before lodging your return. A proactive approach can often save far more than trying to reconstruct expenses at tax time.

If you'd like help identifying every tax deduction you're entitled to and making sure your business remains ATO compliant, contact L & Co for tailored tax advice.

Frequently Asked Questions

1. Do I need receipts for every deduction I claim?

Generally yes. The ATO expects you to substantiate deductions with records — receipts, invoices, or in some cases a logbook (for vehicle use) or diary (for home office hours). Bank statements alone often aren't sufficient proof of a business purpose.

2. Can I claim deductions I forgot about in a previous tax return?

In some cases, yes — you can request an amendment to a previous return, generally within two years for most small businesses. It's worth raising this with your accountant if you think you've missed something in a prior year.

3. What's the difference between a deduction and a tax offset?

A deduction reduces your taxable income before tax is calculated. A tax offset directly reduces the amount of tax you owe. They're not the same thing, and it's a common point of confusion — your accountant can clarify which applies to a specific claim.

4. Is it worth using an accountant instead of doing tax myself for deductions?

Software and DIY tax tools are good at applying rules you already know about. An accountant is more likely to catch deductions specific to your industry or situation that generic software won't prompt you for — which is often where the real savings are.