The Family Law Act states that you are in a de facto relationship with another person if you are not legally married to each other, you are not related by family and you have a relationship as a couple living together on a genuine domestic basis.
To assess if you are living together on a genuine domestic basis, the Court may look to:
•the duration of the relationship;
•the nature and extent of common residence;
•whether a sexual relationship exists;
•the degree of financial dependence or interdependence and arrangements for financial support;
•the ownership, use and acquisition of their property;
•the decree of mutual commitment to a shared life;
•whether the relationship is or was registered under a prescribed law of a State/Territory;
•the care and support of children; and
•the reputation and public aspects of the relationship.
Usually, you will need to demonstrate that you have lived together for at least 2 years (or total periods of 2 years), or that there is a child from the relationship.
Once you are de facto partners, you have the same rights and entitlements as married couples to sort out property settlement (and superannuation) entitlements.
Source: http://www.austlii.edu.au/au/legis/cth/consol_act/fla1975114/s4aa.html
