Sole trader tools

For anyone working for themselves on an ABN: what to charge, GST and your BAS, what you can claim, and how much of each invoice to keep for tax.

How much of this invoice should I keep?

Invoice amount

Including GST

Profit you expect this year

Income less costs, before GST

Registered for GST

Put aside $578: $200 of GST and $378 for income tax.

28 October, February, April and July

If you lodge yourself. Lodging online usually adds two weeks.

Tax on your business profit, and how much of each invoice to put aside for tax and GST.

The hourly rate to charge to earn the same as a salary, after super, time off and business costs.

Whether a contract day rate beats a salary once you pay your own super, leave and costs.

Add 10% GST to a price, or work out the GST in a price that includes it.

What your quarterly BAS will come to: GST on sales, GST credits and PAYG, and when it's due.

Whether cents per kilometre or a logbook gives the bigger car deduction, and the tax it saves.

What you can claim for working from home: the 70c fixed rate, equipment and a business room.

Rates checked September 2026 against the ATO.

GST is 10%. You must register once your turnover reaches $75,000 a year. The GST in a price that includes it is one-eleventh of the price.
Small business income tax offset: 16% of the income tax on your business profit, up to $1,000 a year, if your turnover is under $5 million. It's worked out when you lodge your tax return.
Super isn't compulsory for yourself as a sole trader, but employees get 12%. Personal contributions you claim as a tax deduction count towards the $32,500 concessional cap.
Car: 91c a business kilometre, up to 5,000 km a car, or a logbook for more.
Working from home: 70c an hour with the fixed rate method (the latest published rate).
Quarterly BAS is due on 28 October, 28 February, 28 April and 28 July (later if you use a tax agent).
PAYG instalments: after a year with business income, the ATO usually asks you to pay tax on it each quarter instead of in one bill at tax time.

Tax Refund Estimator - Estimate your return if you also have a job with tax withheld.
Super Projection Calculator - Nobody pays your super for you, so see where your balance is heading.
Car Loan Calculator - Repayments on a work vehicle, including a balloon.

General info only. These calculators are estimates, not tax advice. Your accountant or the ATO can confirm what applies to your business.