Sole Trader Accounting Guide

Sole trader accounting is fairly simple once you understand how the pieces fit together. You need to keep track of your business income and expenses, stay on top of GST and BAS if you’re registered, and report the final result in your individual tax return. Unlike a company, there’s no separate legal entity sitting between you and the business.

This article contains general information only and isn’t personal tax or financial advice. Every business is different, so speak with a registered tax agent, BAS agent or accountant about your specific situation.

What “sole trader” actually means for your accounting

A sole trader is the simplest business structure in Australia, and the accounting reflects that simplicity — but it also means there’s no legal separation between you and the business. Business debts are your personal debts, business income is your personal income, and there’s no separate company tax return sitting between the two.

That matters at tax time because your business profit feeds straight into your personal tax return. If the business earns more, your taxable income generally goes up too. Getting the business figures right isn’t just about the business — it’s about your own tax return.

Setting up your accounting foundation

It’s worth getting a few basics right from the beginning:

• A dedicated business bank account. Not legally required, but running business transactions through the same account as groceries and personal bills makes reconciliation genuinely painful, and makes it far easier to overlook a deductible expense or accidentally count a personal transfer as income.
• Accounting software from the start, even a simple one, rather than a spreadsheet you plan to formalise “later.” Software that reconciles against your bank feed catches errors as they happen instead of six months into the year.
• An ABN, generally required if you’re carrying on a business rather than doing occasional one-off work as a hobby. Your existing individual TFN is what you lodge your tax return under — sole traders don’t get a separate business TFN.
• A decision on GST registration, since it changes how invoices need to be set up from the first sale.

What income and expenses to record

Business income includes everything earned from the business — sales, fees, and any other business receipts — and it’s recorded at the GST-exclusive amount if you’re registered for GST. Our guide to whether taxable income includes GST covers why that exclusion applies and how it interacts with your deductions.

Deductible expenses generally need to be genuinely incurred in earning your business income, with records to substantiate the claim. Common categories for sole traders include:

• Cost of goods or materials directly used in the business
• Business-related vehicle and travel costs
• Home-based business running expenses, using the ATO fixed rate method or actual costs
• Professional fees, insurance and business subscriptions
• Depreciating assets used in the business, with the available deduction depending on the current simplified depreciation rules, asset cost, business use and aggregated turnover

A cost used partly for business and partly for personal purposes — a phone plan, a vehicle, a home office — generally needs to be apportioned between the two, with only the business-use portion claimed. Claiming 100% of a mixed-use expense can also attract attention if the ATO reviews the claim.

GST and BAS obligations

Registration is generally required once GST turnover reaches, or is projected to reach, $75,000, within 21 days of that threshold being reached. Below that, registration is optional — some sole traders register voluntarily anyway, usually to start claiming GST credits on business purchases.

Once registered, GST is charged on taxable sales and reported through the BAS, alongside PAYG instalments and PAYG withholding if you have them. Our GST explained guide and BAS explained guide explain how both work in more detail — this guide focuses on how they fit into your overall sole trader accounting setup.

Income tax as a sole trader

Because a sole trader’s business income flows into their individual return, it’s taxed at individual marginal tax rates, not a flat company rate.

These rates don’t include the 2% Medicare levy, which generally applies on top unless a reduction or exemption applies. If you have other income — a part-time job, investment income — that’s combined with your business income to work out your total taxable income and which bracket applies, rather than your business income being taxed separately.

PAYG instalments

Once business income reaches a certain level, sole traders can be required to prepay income tax through PAYG instalments during the year, rather than paying the full amount as a lump sum at tax time. Individuals generally enter the system automatically when all three criteria apply: instalment income from the latest return is $4,000 or more, tax payable on the latest notice of assessment is $1,000 or more, and estimated or notional tax is $500 or more.

Instalments are based on GST-exclusive instalment income, and they’re a prepayment credited against your final tax bill, not an additional tax. A sole trader whose income fluctuates year to year can find the instalment amount doesn’t match what’s actually owed for the current year — instalments can generally be varied if your circumstances have genuinely changed, rather than continuing to pay instalments that no longer reflect what you’re actually earning.

Superannuation as a sole trader

Employers must pay superannuation guarantee, currently 12% of ordinary time earnings, for eligible workers. As a sole trader, that obligation applies to any staff you employ — it doesn’t apply to yourself, since you’re not your own employee.

As a sole trader, nobody is automatically putting super aside for you. Some sole traders set up a regular personal contribution specifically because nothing else is doing it for them by default; others rely on other savings or investments instead. There’s no single right approach, but it’s something worth thinking about rather than leaving by default.

Record keeping requirements

Records generally need to be kept for at least 5 years, covering income, expenses, GST, and any PAYG instalment or withholding transactions. That includes invoices, receipts, bank statements and records supporting how a deduction was calculated — not just the total amount claimed.

Our business record keeping guide covers what needs to be kept and for how long across the full range of business records, not just sole trader-specific ones.

Common sole trader accounting mistakes

• Mixing personal and business transactions in one account, making it hard to tell what’s genuinely a business expense at tax time.
• Not setting money aside for tax during the year, then facing a large, unexpected bill at lodgment.
• Claiming 100% of a mixed-use expense — a vehicle, a phone, a home office — without apportioning the private-use portion.
• Missing GST registration once the threshold is reached, or continuing to charge GST after deregistering.
• Treating GST collected as available cash, rather than money already owed to the ATO — our GST and taxable income guide covers this cash flow trap in more detail.
• Falling behind on reconciliation, so a year’s worth of transactions needs sorting out all at once instead of a little each month.

DIY vs getting help

Plenty of sole traders manage their own books perfectly well in the early stages, particularly with simple income and no GST registration. It often stops being worth doing everything yourself once GST, employees or more complicated transactions enter the picture — our guide to whether a sole trader needs an accountant explains how to think through that decision.

Quick recap

• Set up a dedicated business bank account and accounting software early
• Register for GST once turnover reaches, or is projected to reach, $75,000
• Apportion mixed-use expenses instead of claiming the full amount
• Set aside tax progressively, rather than waiting for a lump sum bill
• Keep records for at least 5 years, including how each deduction was calculated
• Review whether PAYG instalments and superannuation contributions need attention as income grows

Getting help

Most of the day-to-day bookkeeping is manageable. The problems usually start around GST, mixed personal and business expenses, PAYG instalments, or records that haven’t been kept properly during the year.

If you’d like help setting up or reviewing your sole trader accounting, our small business accounting and BAS services cover sole traders specifically, and our tax accountant service handles the individual tax return your business results flow into.

Official resources

• Business structures — key tax obligations — ATO
• Registering for GST — ATO
• Tax rates — Australian resident — ATO
• Medicare levy — ATO
• Starting PAYG instalments — ATO
• Super guarantee — ATO
• Working from home expenses — ATO
• Instant asset write-off for eligible businesses — ATO
• Detailed business record-keeping requirements — ATO