Broadly, a significant action is an action to acquire interests in securities, assets or Australian land, or otherwise take action in relation to entities (being corporations and unit trusts) and businesses, that have a connection to Australia. For an action to be a significant action, the action must in most cases result in a change in control involving a foreign person or be taken by a foreign person.

Generally, the action is only a significant action if the entity, business or land meets the threshold test. A different threshold test applies for certain significant actions taken in relation to agribusinesses.

The regulations may also prescribe actions that are significant actions.

An acquisition of an interest in Australian land by a foreign person that is specified in an exemption certificate under Division   5 is generally not a significant action.

Division   6 deals with the treatment of entities whose securities are stapled and entities operating on a unified basis.