Ultimate Holding Company
If the company is owned or controlled by another company, by way of shares, deed or other device, then either that company or the 'top level' controlling company, if a higher one exists, must be recorded as the Ultimate Holding Company.
If the company's shareholders are a natural person you will generally not be required to nominate an Ultimate Holding Company, however if there is an Ultimate Holding Company its ACN or ABN must be included; if it is not an Australian company its country of registration must be included.