The AUSTRALIAN TAX OFFICE has now directed that people who are providing ridesharing services like Uber, GoCatch and Limofied must register for GST by 1 August 2015. 

ATO consider the ridesharing services to be a Taxi Services and has taken the same approach to ridesharing as they do to the taxi industry. The ATO believes that providers of ridesharing services must register and pay GST from the first dollar of earnings. 

Here is the link to ATO Fact sheet for the GST on Rideshare Services

Here is another Example:

In Australia, Goods and Services Tax (GST) is applied at the rate of 10% on the supply of most goods and services.

Once you are registered for GST, you need to collect GST on every supply you make to customers. Practically, it means that 10% of GST is included in the gross cost of every ride you provide. Let’s assume, if you collect $11 for a ride, $1 of this will be GST. GST is payable on the gross cost of the ride, before the Limofied commission fee is deducted.

You can offset any GST which you spend on items you bought against your taxable supplies called as tax credits and you may be able to claim a tax credit on the items such as fuel and service costs of your vehicle.

If the collected GST on your rides is more than the GST credits you claim on your expenditures, the difference has to be paid to the ATO. If your credits are more than your taxable supplies, the difference is refundable from the ATO.

This information is not a tax advice. Please consult with a tax professional who can assist you as to whether your individual circumstances requires you to register for GST.