Australian Business Number ABN:
If the annual turnover of your business is $50,000 or more you must register for an Australian Business number and for the Good & Service Tax (GST). Your ABN will also be your GST registration number.
How to work out the cost:
There is no fee to apply for an ABN number; for the financial analysis it will not be included in the costings of your business, however, you must be aware that you CAN NOT register for a business name without an ABN.
Business Name:
Your business name (if it is not your own personal name) must be registered with the Office of Fair Trading & Business Affairs. This is not primarily intended to protect your business name, but to protect consumers.
How to work out the cost:
Registering a Business Name in Victoria costs $71.60 for 3 years (renewals are $51.20).
Source: Victorian Business Channel