Australia's taxation system is a complex one, with many different state and federal taxes. We won't go into too much detail here, but there are some important things you should know.
If you're planning to work in Australia, you'll need to get a tax file number (TFN) from the Australian Tax Office (ATO). It's not mandatory, but without a TFN, you'll automatically be taxed at the highest marginal rate and you may not have access to other benefits which you'd usually be entitled to.
Your employer will ask you for this TFN. And if you have savings and investments earning income, the bank (or other financial institution) managing these assets will also ask for it.
Tax file number applications are usually processed within 28 days, you can find out more on the ATO website.
Australia's financial year runs from July 1 to June 30 each year. If you earn more than a certain amount (you can look this up on the ATO website) during this period, you may need to pay income tax. As an employee, this income tax is normally deducted from your regular earnings. You'll also need to fill out a tax return at the end of each financial year. Depending on your situation, you may either get money back from the ATO, or you may owe them money.
Australia also has a goods and services tax (GST) which is 10% on most things you buy. This is also known as a value added tax in some other parts of the world.