A binding financial agreement cannot include or exclude child support or custody matters in Australia because these are entirely separate areas of law. BFAs are limited to financial and property arrangements under the Family Law Act 1975, while child support is governed by the Child Support (Assessment) Act 1989 and parenting arrangements are always determined by the Family Court based on the child’s best interests at the time of separation.
Any attempt to address children’s issues inside a BFA will not only be unenforceable but could put the entire agreement at risk of being set aside.
This article explains why the law draws this line, what happens if a BFA includes children’s clauses, and what options actually exist for parents who want certainty around their children’s financial and care arrangements.
Why Can a BFA Not Address Child Custody or Parenting Arrangements?
A BFA cannot address child custody or parenting arrangements because the Family Court must always have the power to make decisions about children based on their circumstances at the time of separation, not based on an agreement made months or years earlier.
Under section 60CA of the Family Law Act 1975, the best interests of the child are the paramount consideration whenever a court makes a parenting order.
This means no private contract between two adults can override the court’s obligation to assess what is best for a child when the family situation actually changes.
Section 60CC of the Act sets out the specific factors the court must weigh when determining a child’s best interests.
These include the safety of the child, the benefit of the child having a meaningful relationship with both parents, the child’s own views (depending on maturity), and any history of family violence or abuse.
Every one of these factors depends on the real-life circumstances at the time of separation, not on what two people predicted when they signed a financial agreement before or during their relationship.
A clause in a BFA that attempts to dictate who a child lives with, how much time they spend with each parent, or how parental responsibility is allocated would have no legal effect.
The court would simply disregard it.
What Happens If a BFA Contains a Parenting Clause?
If a BFA contains a parenting clause, it will be treated as unenforceable because it falls outside the scope of what the Family Law Act permits a financial agreement to cover.
Sections 90B, 90C, and 90D of the Family Law Act define the matters that a BFA can validly address.
These are limited to how property and financial resources will be dealt with in the event of a relationship breakdown, and the maintenance of either party.
Parenting arrangements are not listed among the permissible matters.
Including a clause about child custody or parenting time does not automatically void the entire BFA, but it creates a serious risk.
If one party later challenges the agreement, the presence of provisions that attempt to deal with matters outside the scope of the legislation could be used as evidence that the agreement was poorly drafted or that the legal advice provided was inadequate.
Courts have set aside BFAs on the basis of technical deficiencies, and a parenting clause sitting inside a financial agreement is a clear procedural red flag.
The safest approach is to keep parenting matters entirely separate from a BFA and address them through the proper legal channels when they become relevant.
Why Can a BFA Not Determine Child Support Payments?
A BFA cannot determine child support payments because child support in Australia is governed by a completely separate legislative framework designed to protect the financial rights of children.
The Child Support (Assessment) Act 1989 establishes a formula-based system for calculating child support liabilities.
This formula takes into account the income of both parents, the percentage of care each parent provides, and the costs of raising children at different ages.
The system is administered by Services Australia (Child Support), and either parent can apply for an administrative assessment at any time after separation.
The underlying principle is that every child has an independent right to financial support from both parents.
This right cannot be contracted away by the parents in a BFA or any other private agreement.
Even if both parties agreed at the time of signing the BFA that neither would seek child support, that clause would have no legal standing.
Either parent could still apply to Services Australia for an assessment, and the Registrar would process it according to the statutory formula regardless of what the BFA says.
How Is Child Support Actually Calculated in Australia?
Child support in Australia is calculated using a formula set out in Part 5 of the Child Support (Assessment) Act 1989 that considers both parents’ incomes, their percentage of care, and the costs of raising children at different ages.
The formula determines each parent’s share of the combined parental income and compares it to their share of care to work out who pays and how much.
The parent with the higher income percentage relative to their care percentage is typically the one who pays child support.
The formula exists to ensure that children receive a proper level of financial support based on their parents’ actual capacity to pay, and it adjusts as incomes and care arrangements change over time.
This is fundamentally different from a BFA, which locks in financial terms based on circumstances at a single point in time.
What Is the Difference Between a BFA and a Binding Child Support Agreement?
A BFA and a binding child support agreement are two entirely different legal instruments governed by different legislation and serving different purposes.
The following table summarises the key differences between these two types of agreements.
| Binding Financial Agreement (BFA) | Binding Child Support Agreement | |
|---|---|---|
| Governing legislation | Family Law Act 1975 (Part VIIIA) | Child Support (Assessment) Act 1989 (Part 6) |
| Scope | Property division, financial resources, spousal maintenance | Child support payments only |
| When it can be made | Before, during, or after a relationship | Only when children already exist |
| Court involvement | None required | None required, but registered with Services Australia |
| Independent legal advice | Required for both parties | Required for both parties |
| Can it be varied? | Yes, by mutual agreement with new legal advice | No, must be terminated and replaced with a new agreement |
| Administered by | Private contract between the parties | Services Australia (Child Support) |
A BFA is made under Part VIIIA of the Family Law Act 1975 and deals with property division and spousal maintenance between the parties to a relationship.
A binding child support agreement, by contrast, is made under Part 6 of the Child Support (Assessment) Act 1989 and deals specifically with child support payments.
The two cannot be combined into a single document.
A binding child support agreement allows parents to agree on child support arrangements that differ from the standard formula assessment.
The agreed amount can be more or less than what would be payable under the formula.
However, both parents must receive independent legal advice before signing, and each must obtain a legal certificate confirming that advice was provided.
Once accepted by the Registrar of Child Support, a binding child support agreement is legally enforceable.
It is important to understand that a binding child support agreement can only be made when there are existing children whose support needs can be identified.
You cannot include a binding child support agreement as part of a prenuptial BFA for children who have not yet been born.
The children must exist, and their specific circumstances must be known, before any binding arrangement about their financial support can be formalised.
Can a Binding Child Support Agreement Be Changed or Terminated?
A binding child support agreement can be changed or terminated, but only through specific legal processes, and it is deliberately difficult to set aside.
Both parents must agree to end the agreement, and a new agreement or a court order must replace it.
Alternatively, a court can set aside a binding child support agreement under section 136 of the Child Support (Assessment) Act 1989 if exceptional circumstances arise.
If care arrangements change significantly after the agreement is made, this can also affect its operation.
For example, if the agreement does not account for changes in care percentages, it may end from the date of the care change.
Parents are required to notify Services Australia immediately of any change in care arrangements.
This is another reason why child support matters cannot be locked into a BFA.
Children’s needs and living arrangements evolve constantly, and the legal system requires flexibility to respond to those changes in ways that a fixed financial agreement cannot provide.
What Can a BFA Actually Cover When Children Are Involved?
A binding financial agreement can cover financial and property matters that indirectly affect children, even though it cannot directly address custody, parenting, or child support.
If children are part of the relationship, or if the couple plans to have children, the BFA should acknowledge that possibility and account for how it might affect the fairness of the financial arrangements.
A well-drafted BFA will include provisions that recognise the financial impact of having children.
For example, it might address how the family home will be treated if one party becomes the primary carer after separation.
It could also deal with how assets accumulated during the relationship will be divided in light of one party having reduced their earning capacity to care for children.
Spousal maintenance is another area where a BFA can provide for the financial needs of a parent who takes on primary caring responsibilities.
The agreement can set out whether maintenance will be payable, the amount, and the duration of payments.
This is separate from child support and is permissible within a BFA because it relates to the financial relationship between the two parties rather than the rights of the child.
Why Should a BFA Account for the Possibility of Children?
A BFA should account for the possibility of children because failing to do so is one of the most common reasons agreements are later challenged and set aside.
Under section 90K of the Family Law Act, a court can set aside a BFA if there has been a material change in circumstances relating to the care, welfare, or development of a child, and enforcing the agreement would cause hardship to the child or the parent caring for them.
If a couple signs a prenuptial BFA that says each party keeps what they brought into the relationship and there is no mention of children, the entire agreement could be at risk if children are later born and one parent sacrifices their career to provide care.
The court may find that the agreement is impracticable or unjust in light of the changed circumstances.
This does not mean the BFA needs to determine custody or child support.
It means the financial terms should be drafted with enough foresight and flexibility to remain fair even if the couple’s circumstances change significantly due to the arrival of children.
How Are Parenting Matters Handled Separately from a BFA?
Parenting matters are handled separately from a BFA through either informal arrangements between the parents, a parenting plan, consent orders, or court-ordered parenting orders.
The most straightforward option is for parents to reach their own informal agreement about where the children will live and how time with each parent will be shared.
While this approach is flexible and cost-effective, it has no legal enforceability, which means either parent can change the arrangement at any time.
A parenting plan is a written agreement between the parents that sets out the arrangements for the children.
It is not legally enforceable in the same way as a court order, but it carries weight in court proceedings if disputes later arise.
Parenting plans can cover who the child lives with, how time is shared, communication arrangements, and how major decisions about education, health, and religion are made.
For greater certainty, parents can apply for consent orders through the Federal Circuit and Family Court of Australia.
Consent orders are legally binding and enforceable by the court.
They can address both parenting arrangements and property matters, although the court must be satisfied that the proposed parenting orders are in the best interests of the child before approving them.
If parents cannot agree, either party can apply to the court for parenting orders.
The court will then determine the arrangements based on the best interests of the child under section 60CC of the Family Law Act.
Before applying to the court, parents must generally attend family dispute resolution (also known as mediation) and obtain a certificate from an accredited practitioner, unless exceptions apply in cases involving family violence, child abuse, or urgent risk of harm.
If mediation is successful, the agreement can be formalised into a parenting plan or consent orders without the need for contested court proceedings.
What Risks Arise from Trying to Include Children’s Matters in a BFA?
Trying to include children’s matters in a BFA creates legal risks that can undermine the enforceability of the entire agreement.
The most immediate risk is that any clause dealing with child custody, parenting time, or child support will be unenforceable.
Courts will simply ignore those provisions because they fall outside the scope of what a financial agreement can lawfully address.
The greater risk, however, is that including such clauses could cast doubt on the quality of the legal advice each party received before signing.
One of the requirements for a valid BFA under section 90G of the Family Law Act is that both parties must receive independent legal advice about the effect of the agreement on their rights and the advantages and disadvantages of making the agreement.
If a lawyer allows a BFA to include provisions about children without advising the client that those provisions are unenforceable, this could be used as evidence that the legal advice was inadequate.
Inadequate legal advice is a recognised ground for setting aside a BFA, and courts have acted on this basis in multiple cases.
The inclusion of unenforceable clauses can also create confusion about the parties’ intentions and expectations.
If one party believed the parenting clause would be binding, they may not have taken steps to formalise parenting arrangements through the proper legal channels, leaving them without protection when separation occurs.
Could a BFA Be Set Aside Because of Children?
A BFA could be set aside because of children if a material change in circumstances relating to the care, welfare, or development of a child makes the agreement impracticable or causes hardship.
Section 90K(1)(d) of the Family Law Act specifically provides that a court may set aside a BFA where, since the agreement was made, a material change in circumstances has occurred relating to the care, welfare, or development of a child of the relationship, and as a result, the child or the party caring for the child would suffer hardship if the court did not set aside the agreement.
This is a critical provision for couples who sign a BFA before having children.
If the BFA does not adequately account for the possibility of children, and one party later becomes the primary carer at significant personal and financial cost, the court has the power to set aside the agreement entirely.
This underscores the importance of drafting a BFA that, while not dealing with child support or custody directly, is structured to remain fair and workable in a range of future scenarios, including the birth or adoption of children.
Need Help With Your Binding Financial Agreement?
A binding financial agreement is a powerful tool for protecting your financial interests, but it must be drafted within the boundaries of what the law allows.
Child support and custody matters sit outside those boundaries and must be addressed through separate legal mechanisms.
Getting the structure right from the outset means your BFA is more likely to withstand scrutiny and remain enforceable for years to come.
As BFA lawyers in Australia, my law firm can help you draft a binding financial agreement that properly protects your assets while complying with all legal requirements under the Family Law Act 1975.
Contact us today by calling 1300 529 888.
Frequently Asked Questions
Can You Put Child Custody Arrangements in a Binding Financial Agreement?
No, you cannot put child custody arrangements in a binding financial agreement in Australia. BFAs are limited to financial and property matters under the Family Law Act 1975. Parenting arrangements must be determined separately through parenting plans, consent orders, or court orders, always based on the child’s best interests at the time of separation under section 60CC of the Act.
Does Having Children Affect the Validity of an Existing BFA?
Having children can affect the validity of an existing BFA if the agreement did not account for this change. Under section 90K of the Family Law Act, a court can set aside a BFA where a material change in circumstances relating to a child’s care or welfare causes hardship. BFAs should always be drafted with future children in mind.
What Is the Difference Between a BFA and a Binding Child Support Agreement?
A BFA covers property division and spousal maintenance under the Family Law Act 1975, while a binding child support agreement covers child support payments under the Child Support (Assessment) Act 1989. They are separate legal instruments that cannot be combined. A binding child support agreement requires independent legal advice for both parents and applies only to children who already exist.
Can Parents Agree to Waive Child Support in a BFA?
No, parents cannot agree to waive child support in a BFA or any other private agreement. Every child in Australia has an independent legal right to financial support from both parents under the Child Support (Assessment) Act 1989. Either parent can apply to Services Australia for an assessment at any time after separation, regardless of any private agreement.
Should a BFA Mention Children at All?
Yes, a well-drafted BFA should mention the possibility of children even though it cannot determine custody or child support. Accounting for how caregiving responsibilities may affect the financial arrangements helps protect the agreement from being set aside later. A BFA that ignores children entirely is more vulnerable to challenge under section 90K of the Family Law Act.
What Legal Options Exist for Formalising Parenting Arrangements in Australia?
Parents in Australia can formalise parenting arrangements through informal agreements, written parenting plans, consent orders approved by the Federal Circuit and Family Court, or court-ordered parenting orders. Consent orders provide the strongest legal enforceability. Before applying for court orders, parents must generally attend family dispute resolution unless exceptions such as family violence apply.