Family Law

We are not married. When will Australian law impose a "de facto” relationship such that we become automatically financially intertwined + liable to a property settlement if we separate?

When can an application for a financial Property Settlement be made to the Family Court?

The circumstances governing whether a "de facto” relationship will be imposed by Australian law for the purposes of making an application to the Family Court for a financial property settlement generally can only arise when one of the following legally prescribed circumstances is present [1]:

1️⃣ Two adult persons who are not married or related by family live together as a couple in a "genuine and permanent domestic relationship” for at least two years (this can include more than one period providing it totals at least 2 years);

2️⃣ There is a child of the relationship;

3️⃣ There have been significant contributions made and a serious injustice would result if the court did not make an order or declaration; or

4️⃣ The de facto relationship has been registered in a State or Territory under laws for the registration of relationships.

When does a “de facto” relationship exist?

In the recent case of Radecki & Fairbairn [2020] FamCAFC 307 the Full Court of the Family Court of Australia at Sydney in their judgment dated 11 December 2020, confirmed the relevant law to determine the existence of a de facto relationship from para. 26 as follows:

A de facto relationship exists where a Court finds that the parties were “a couple living together on a genuine domestic basis” (s 4AA(1)(c) of the Act), which is to be decided by reference to the matters set out in s 4AA(2) of the Act, which are as follows:
(a) the duration of the relationship;
(b) the nature and extent of their common residence;
(c) whether a sexual relationship exists;
(d) the degree of financial dependence or interdependence, and any arrangements for financial support, between them;
(e) the ownership, use and acquisition of their property;
(f) the degree of mutual commitment to a shared life;
(g) whether the relationship is or was registered under a prescribed law of a State or Territory as a prescribed kind of relationship;
(h) the care and support of children;
(i) the reputation and public aspects of the relationship.
In addition, the Court “is entitled to have regard to such matters… as may seem appropriate to the court in the circumstances of case” (s 4AA(4) of the Act).
In a passage which has been frequently quoted and applied when determining the existence of a de facto relationship (see, for example, Sinclair & Whittaker (2013) FLC 93-551 (“Sinclair & Whittaker”) at [55] and Cadman & Hallett (2014) FLC 93-603 (“Cadman”) at [48]), albeit in a different legislative context, Fitzgerald J said in Lynam v Director-General of Social Security(1984) FLC 91‑577 at 79,663:
Financial arrangements cannot be taken in isolation and considered of particular importance in determining the nature of relationship.
Their materiality, like each of the other elements of the relationship, stems from the impact which they have as part of an overall situation.
Each element of a relationship draws its colour and its significance from the other elements, some of which may point in one direction and some in the other.
What must be looked at is the composite picture.
Any attempt to isolate individual factors and to attribute to them relative degrees of materiality or importance involves a denial of common experience and will almost inevitably be productive of error.
The endless scope for differences in human attitudes and activities means that there will be an almost infinite variety of combinations of circumstances which may fall for consideration.
In any particular case, it will be a question of fact and degree, a jury question, whether a relationship between two unrelated persons of the opposite sex meets the statutory test.
Although not expressly mentioned in s 4AA(2) of the Act, an intention to enter into a de facto relationship or to end one is powerful evidence to be taken into account under s 4AA(4) of Act, in determining whether such a relationship exists or has ended.
Whilst evidence of such intention is not required and, in many cases, is not present, where such an intention can be identified, it can be telling.


[1] s. 90SB of the Family Law Act 1975 (Cth.).

[2] Joint judgment of May, Strickland & Ainslie-Wallace JJ reported at 86,682.

[3] Paragraph 94 of the joint judgment of Bryant CJ, Thackray & Aldridge JJ reported at 87,398.

What is the effect of a Binding Financial Agreement (BFA)?

A legally valid* Binding Financial Agreement (BFA) will operate to prevent the Court from being able to make property adjustment orders under the Family Law Act 1975.

A Binding Financial Agreement (BFA) can also deal with spousal maintenance and prevent your former partner from filing an application for spousal maintenance.

Important Note:

* In order to be legally valid and actually in fact “legally binding”, a Binding Financial Agreement (BFA) must not be susceptible to being set aside by the Court for any reason.

For a detailed discussion of when a Binding Financial Agreement (BFA) can be set aside, please refer to the separate FAQ on this topic.

When can a Binding Financial Agreement (BFA) be set aside?

Can the BFA be set aside if it represents a “Bad Deal” for one of the parties?

In the case of Hoult & Hoult [2013] FamCAFC 109 Strickland and Ainslie-Wallace JJ opined at para. [310]:

“ … The point of the legislation is to allow the parties to decide what bargain they will strike, and provided the agreement complies with the requirements of section 90G(1) they are bound by what they agree upon.  

Significantly, in reaching agreement, there is no requirement that they meet any of the considerations contained in section 79 of the Act, and they can literally make the worst bargain possible, but still be bound to it."  

Setting aside a Binding Financial Agreement (BFA)

If any of the following apply the Binding Financial Agreement (BFA) can be set aside by the courts:

1️⃣ A party did not receive independent legal advice prior to signing the BFA

2️⃣ A party has received inadequate or wrong legal advice from their lawyer prior to signing the BFA

3️⃣ A party was advised by a lawyer but they were not an Australian Lawyer

4️⃣ The BFA was signed under duress

Make sure there is plenty of time.

Watch out for the looming wedding date which could provide a basis for a claim of undue influence or duress.

5️⃣ The BFA was signed under undue influence

If a party does not have a good command of English, DO NOT allow the intended partner or a relative to act as an interpreter.

This may lead to allegations of undue influence or duress or that the party did not understand the BFA.

6️⃣ Fraud/Unconscionable conduct was involved

Failure to make full and complete disclosure of all material matters constitutes “Fraud”

If a party to a Binding Financial Agreement (BFA) is aware of relevant information and does not disclose it to the other party, whether intentionally or non-intentionally, the Court may set the agreement aside at a later date, under section 90K of the Family Law Act:

"A court may make an order setting aside a financial agreement if and only if, the court is satisfied that: the agreement was obtained by fraud (including non-disclosure of a material matter)…"

What might constitute “Fraud” in the context of a BFA?

❌ If a party fails to disclose the true extent or value of his or her assets.

This might occur, by way of example, if a party:

➲ Hides assets;

➲ Mistakenly assumes the assets don't need to be disclosed, such as property held in the name of a Trust which they directly control, or property held overseas which the other party knows nothing about, or cryptocurrency they have forgotten they own but could become worth a material sum;

❌ Not disclosing the true value of assets, or material information which could assist to determine the true value of assets;

❌ Failure to disclose other material information which would impact on a person's decision to enter into the Binding Financial Agreement; or

❌ Deceiving the other party in some way, in order to induce them to sign the Binding Financial Agreement.

In such a case, he or she would create an inherent weakness in the Binding Financial Agreement, leaving the possibility open for it to be challenged at a later date by the disgruntled ex-partner.

7️⃣ There has been a material change in circumstances relating to the care. welfare and development of a child …

Family Law Act 1975 (Cth.)

90K         Circumstances in which court may set aside a financial agreement or termination agreement

(1)          A court may make an order setting aside a financial agreement or a termination agreement if, and only if, the court is satisfied that:

(d)          since the making of the agreement, a material change in circumstances has occurred (being circumstances relating to the care, welfare and development of a child of the marriage) and, as a result of the change, the child or, if the applicant has caring responsibility for the child (as defined in subsection (2)), a party to the agreement will suffer hardship if the court does not set the agreement aside; or

8️⃣ Lawyers' Laundry List of Avoidable Mistakes

These avoidable mistakes made by one or both of the parties lawyers were incapable of rectification by the Court.

This meant that the Court had no choice but to invalidate and set aside the BFA in the following situations:

➲ The wrong type of Binding Financial Agreement was entered;

➲ There were mistakes in one or both of the Lawyer's Certificates;

➲ The BFA was executed by a party before receipt of legal advice;

➲ Out-dated Lawyer Certificates were used;

➲ The lawyer failed to record the advice provided and have the party sign an acknowledgement of having received the advice;

➲ There were other legally technical matters wrong regarding the BFA such as it being signed in counterparts or a translator was delegated to provide the legal advice.

9️⃣ The BFA was entered to defraud or defeat the interests of third parties

❌ If a party enters a BFA for the purpose of defrauding or defeating the interests of creditor/s or another person who might claim rights due to the existence of an additional de facto relationship.

What is the effect of setting aside the BFA?

If a Binding Financial Agreement (BFA) is set aside, it means that it is “as if” the original agreement never existed.

Either party is then free to commence proceedings seeking a property settlement and/or spousal maintenance.

By Mutual Agreement: Update BFA or file Consent Orders with the Court

If at anytime, for any reason both parties agree, the parties could decide to replace the BFA with an alternative or updated BFA.

Important: All of the above notes regarding setting aside a BFA, apply to any alternative or updated BFA.

The same rigor must be applied. New certificates of independent legal advice must be obtained, etc.

If the parties have separated, it is also possible for the terms of a BFA to be overridden by consent orders filed with the Court (subject to amendment by the Court if they are deemed not to be fair and equitable).


The legal term “set aside” means to declare a legal agreement, decision or process to be invalid.

‍Is a Binding Financial Agreement (BFA) the same as a Prenup?

The legal term Binding Financial Agreement (BFA) is the correct wording to use in Australia for this kind of agreement.

Q: It's the same thing as a prenup right?
A: Yes, sort of …

In order to provide some context, a Binding Financial Agreement (BFA) has in the wider community (including overseas and in the media) commonly and historically been referred to as a Prenuptial agreement or Prenup.

A Binding Financial Agreement (BFA) can be entered at any time

1️⃣ As a Prenup, Postnup, after the parties have separated, or in the case of de facto relationships, at any time in the absence of nuptials altogether; and could alternatively be

2️⃣ Called a Separation Agreement, Cohabitation Agreement or Divorce Agreement.

Just because the name uses the word “Binding” does not make it so!

Whilst the parties may include the word binding in the name or within the body of the agreement, simply using the word binding does not of itself make the agreement legally binding.

Whether a Binding Financial Agreement (BFA) is in fact legally binding* is a determination which can only be made by the Court.

Important Note:

* In order to be legally valid and actually in fact “legally binding”, a Binding Financial Agreement (BFA) must not be susceptible to being set aside by the Court for any reason.

For a detailed discussion of when a Binding Financial Agreement (BFA) can be set aside, please refer to the separate FAQ on this topic.

We have separated or are thinking about separation. What do we need to read + understand first about seeking assistance, child custody + financial matters?

The Family Court of Australia prescribes as mandatory reading the following Fact Sheets.

Whilst it may appear counter-intuitive, starting here will maximise the chances of you resolving your differences +/or settling matters outside of the Family Court.

Marriage, families and separation

This brochure provides information for people considering, or affected by separation or divorce.

It includes information about:

  • the social and legal effects of separation;
  • the services provided to families by the Family Court of Australia and Federal Circuit Court of Australia and by government, community and other agencies, and
  • some of the steps involved in court proceedings.

Pre-action procedure for parenting cases

This brochure provides information for people considering applying to a court for parenting orders.

Pre-action procedures apply to financial cases.

This brochure provides information for people considering applying to a court for financial orders.

Compulsory Family Dispute Resolution
➲ Court procedures and Requirements

For more free information + resources generally

Please refer to our Australian Family Law Resources + Dispute Resolution -> Smart List