Business name registration:

 If you trade under a name that is different from your personal name, you need to register a business name with the Australian Securities and Investments Commission (ASIC). The registration is valid for one year and can be renewed annually.

Company registration:

To register a company in Australia, you need to complete an application and lodge it with ASIC. The company must have at least one director who is an Australian resident and a registered office in Australia.

ABN and TFN: 

Once the company is registered, you need to apply for an Australian Business Number (ABN) and a Tax File Number (TFN) from the Australian Taxation Office (ATO).

Other Requirements: 

Depending on your business structure and industry, there may be other requirements, such as registering for Goods and Services Tax (GST), obtaining licenses and permits, and registering for workers' compensation.