What both domains have in common
Both are Australian .au domains and require an Australian presence. The provider checks your details when you register, renew or transfer the domain.
Why choose .com.au?
Australian customers know .com.au and it is intended for commercial use. Your chosen domain may need to match or connect with your legal name, business name, trade mark or business activity.
Why choose .au?
The shorter .au can be easier to say, advertise and type on a phone. You still need an Australian presence, and the provider may need to confirm your identity.
Available does not always mean eligible
A domain can be unregistered while you still need to prove that you meet the Australian presence, naming or identity rules. Treat it as yours only after the registrar confirms registration.