GST is a goods and services tax. GST is not payable by businesses not registered for GST. If your business income is less than $75,000 per annum you do not need to register for GST but can register voluntarily. If your business income reaches $75,000 pa you are required to register for and pay 10% GST. Once your business is registered for GST, you must pay GST on all fees collected regardless of whether your business income is below the $75,000 threshold.