De Facto Relationships in Australian Law

10 November 2025 in Family and Divorce Law | 6 min read | skip to FAQs

This article explains how de facto relationships are defined and dealt with under Australian family law. We examine the statutory definition in Section 4AA of the Family Law Act 1975 (Cth) and the financial jurisdiction for separated de facto partners under Part VIIIAB. We also discuss the role of binding financial agreements in de facto relationships.

What is a De Facto Relationship?

A de facto relationship is seen to exist where two people, who are not legally married to each other and not related by family, have a relationship as a couple living together on a genuine domestic basis. This is covered by section 4AA of the Family Law Act 1975 (Cth) which assesses all of the relationships circumstances, including:

1. The duration of the relationship
2. The nature and extent of common residence
3. Whether a sexual relationship exists
4. The degree of financial interdependence or dependence
5. Ownership, use and acquisition of property
6. The degree of mutual commitment to a shared life
7. Care and support of children
8. The reputation and public aspects of the relationship

No one single factor from the above list is determinative, and not all facts need to be present (according to section 4AA(2)). For example, a person can be married to someone else, yet still be in a de facto relationship with another partner.

When Does a De Facto Relationship Break Down?

Unlike a marriage, which ends upon the parties getting divorced, a de facto relationship ends when the parties separate and no longer live together on a genuine domestic basis (based on section 4AA(1). Parties separating does not necessarily require that the parties live in different residences. It can occur while the parties are living together under one roof, where the evidence shows that one or both parties regarded the relationship as ended. This can either be through conduct that has been communicated, or that is otherwise clear from the circumstances.

Courts often look at objective evidence highlighting separation, such as:

1. Whether one party expressed an intention to end the relationship;
2. Changes in sleeping arrangements, intimacy and financial interdependence;
3. Whether household tasks continued jointly or separately;
4. How the parties presented themselves publicly (for example, telling family they had separated), and
5. Whether either party began a new relationship.

This date is important, as the two year limitation runs from the date of final separation. Records such as emails, text messages or bank statements showing separation of finance can all support the position of a party that they separated on a certain date. If the parties disagree, the court makes a determination on the date of separation.

How does the Court determine whether to make Orders?

Since 1 March 2009, eligible de facto couples may have property settlement and maintenance determined in the same way as married couples. There are three threshold elements that must be satisfied before the court will make orders relating to the breakdown of a de facto relationship:

A. A de facto relationship existed and has broken down;

B. At least one of the following must be met under section 90SB:

1. 1. the de facto relationship existed for a total period of at least two years, or
   2. there is a child of the relationship, or
   3. the relationship is or was registered under a prescribed State or Territory law, or
   4. one party made substantial contributions (financial, non-financial, or to the welfare of the family) and serious injustice would result if an order were not made.

C. There must be a sufficient connection to a participating jurisdiction, and the breakdown must be after 1 March 2009.

Is there a Time Limit For Property Settlement when De Facto Relationships break down?

Applications for de facto property settlement or maintenance must be made within two years of separation. An application filed which extends beyond this timeframe can only be made with the courts leave, which is only granted for cases of hardship. In some cases of a de facto relationship breaking down, it is contested as to when the relationship “broke down”, which can cause issues when one party applies for de facto property settlement.

How does the Court Decide Financial Matters when De-Facto Relationships break down?

Financial matters involving de facto couples follow the same steps as cases involving marriage. This is based on the Part VIIIAB provisions that mirror Part VIII. Relying on section 90SM for alteration of property interests and section 90SF(3) for maintenance factors, the accepted structure and progress of a matter is usually:

1. Identifying the net property pool and any relevant superannuation interests
2. Identify and assess and the parties financial, non financial, homemaking and caretaker contributions over the whole relationship.
3. Assess the parties future needs based on the section 90SF(3) factors which includes income disparity, care of children, health, age and earning capacity.
4. Consider whether the proposed orders would be considered ‘just and equitable’ by the FCFCOA.

How Does the Court Decide Maintenance for De Facto Partners?

A separated de facto partner may seek maintenance from their separated spouse where they cannot adequately support themselves and the other party has the capacity to pay. The Court applies section 90SF(1) – (3) which draws from the section 75(2) factors including age, health, income, property, earning capacity, care of children and the standard of living that is reasonable in the circumstances. Maintenance payments can be periodic or a lump sum payment.

Binding Financial Agreement For De Facto Couples

De facto partners can elect to enter into a binding financial agreement under Part VIIIAB:

1. Section 90UB before the relationship begins to protect existing assets
2. Section 90UC during the relationship to clarify ownership over certain assets
3. Section 90UD after breakdown of the relationship to formalise property settlement.

Binding financial agreements, also known as BFAs are a written agreement that allows de facto partners to determine how their property, financial resources and maintenance will be dealt with. If they are made prior to entering a de-facto relationship, they are often called ‘pre-nuptial agreements’. To be binding, there are strict formal requirements under the Act which must be met, such as the agreement being in writing, signed by both parties, and each party must receive independent legal advice about the effect of the agreement, and its advantages and disadvantages. For further information please see our article on What is a Prenuptial Agreement?

The Court has the power to set aside a BFA in limited circumstances under section 90UM of the Act, including in circumstances of:

1. Fraud, including non disclosure of assets;
2. Impracticability in carrying out the agreement;
3. Unconscionable conduct during its formation;
4. Material changes relating to the care of a child causing hardship.

How can BSM Sydney Lawyers assist you?

Parties in a de facto relationship can access all family law services including those relating to property settlement, parenting orders, spousal maintenance and binding financial agreements. The experienced family lawyers at BSM Lawyer Sydney can assist by explaining the law as it relates to you and helping you access your legal entitlements. We can also help resolve disputes between de-facto partners. We are proud of the fact that over 95% of our family matters are settled with negotiation, rather than proceeding to litigation. Not progressing to court saves you money, time and stress In a small percentage of cases, litigation is required and we have the experience to represent you effectively in court. For complex conflicts we have a panel of family law barristers who we call upon to represent you. The senior family lawyers at Brander Smith McKnight Sydney Lawyers offer a free 20-minute consultation.

FAQs

BSM Lawyer Sydney has offices conveniently located in Sydney CBD, Sutherland, Parramatta, Shellharbour and Wollongong.