For the purpose of company registration, there is a specific question in the company entities section asking whether the entity has a ‘former name’.
If you have undergone a name change in the past for any reason this may apply to you. For example, you may have a maiden name, family name, birth or cultural name that is different to the name you currently use.
N.B. The ATO is likely to already have a record for you, from the time when you first received your personal TFN. If your name has changed since that time, include your former name in the application. It is a good idea to call the ATO if you are in any doubt to confirm the name they have on record for you and to make any necessary changes if the name they have is now incorrect.