Do I need to register a new business name to trade as it

I am currently working on a new start up, we have some capital and are currently "trading as" the potential new company name, through an existing business.

My question is do I need to register this potential business name to trade under it, or can I just use it as a placeholder until we make a final decision on the name.

I am in Australia, if that makes any difference.

We're in Australia too, and you don't have to register a business name to trade as it, but you do need at least some business behind it. You can then 'trade as' anything you want, you don't actually need to notify the govt.

e.g., you can have a registered business named 'My Company', but you can trade as 'SomeotherCo' if you want without any issue. This lets you have one business, but have a bunch of startups below that one banner while you figure out if you want to set them up as their own self standing business.

You may not be required to register, but why wouldn't you. Registration protects the name for your use in a particular industry. What happens if multiple companies are using the same name for a product, service, or business? It would make for a very confusing marketplace and a raft of lawsuits.