While you’re at it, fend off wannabes by registering other Australian domain names, too. Just keep in mind that, depending on the type of domain, you may be required to meet an applicable set of criteria as defined by .au Domain Administration at auda.org.au.
When you buy .com.au, here are some other domain names to consider:
.net.au
If you’re registering a .com.au domain name for your business, you might choose to register .net.au as well — especially if your business is in networking or technology. Remember, you need an active ABN/ACN to register .net.au.
.org.au
Charities and not-for-profit (NFP) organizations may register a .org.au. This extension is restricted to political parties, trade unions, sporting and special interest clubs and charities with the right credentials.