Updated 25 October 2026
CM Law's Ultimate 50 List - Separated Couples FAQ #6: Can a separation agreement be modified?
A separation arrangement can sometimes be changed, but the correct process depends on the document and the issue it addresses. An informal agreement, a binding financial agreement, property consent orders and parenting orders have different legal effects. Losing a job or disagreeing with an earlier bargain does not automatically entitle someone to reopen a completed property settlement.
At CM Lawyers, we recommend identifying the existing document before discussing replacement terms. Bring the complete signed agreement, any legal advice statements and all court orders. We can then assess whether you need a new agreement, an application to vary orders, enforcement of existing obligations or advice about setting an agreement aside.
Identify what your separation agreement actually is
The label on the document is not decisive. A signed letter recording who keeps the furniture is different from a financial agreement made under the Family Law Act 1975. An informal document should not be assumed to finally exclude family law claims merely because both partners signed it. Its wording, circumstances and any steps already taken require review.
For property and finances, the Federal Circuit and Family Court of Australia explains two formal options: consent orders and financial agreements. Consent orders are made by the Court; financial agreements are private arrangements subject to technical statutory requirements. Neither should be confused with a parenting plan or child support agreement. One separation may involve several documents, each needing separate attention.
Replacing a binding financial agreement by consent
If both parties want different financial terms, do not rely on handwritten changes, an email exchange or a generic deed of variation. The statutory route is generally a replacement financial agreement expressly terminating the earlier one, or a compliant written termination agreement followed by appropriate new arrangements. Sections 90J and 90UL of the Family Law Act address termination for married and de facto couples respectively.
Independent legal advice is central to this process. Each partner needs their own advice about the proposed document’s effect on their rights and its advantages and disadvantages, with the required practitioner statements and other formalities addressed. A properly made financial agreement does not ordinarily require court approval. That is a different process from asking the Court to make consent orders.
Before signing, update financial disclosure and check what has already happened under the original agreement. A completed property transfer, mortgage liability or superannuation split cannot simply be ignored in the replacement drafting. Obtain advice about implementation and any lender, trustee, tax or registration requirements.
When a financial agreement may be set aside
Without agreement, a party seeking to set aside a financial agreement must establish an applicable legal ground. Under sections 90K and 90UM, these can include fraud involving material non-disclosure, circumstances making performance impracticable, and unconscionable conduct. A material change concerning a child’s care, welfare or development can also be relevant where the statutory hardship requirements are met.
These are specific tests. Financial disappointment, a lower business valuation or a changed preference does not by itself establish a right to rewrite the bargain. The Court’s financial agreement guidance stresses the technical nature of both enforceability and setting-aside questions. Keep the original documents and evidence of the alleged problem; do not assume an application automatically suspends your obligations.
A real case about pressure when signing
In Thorne v Kennedy [2017] HCA 49, the High Court considered financial agreements signed shortly before and after a wedding. Ms Thorne had received independent advice against signing, but the surrounding circumstances included substantial dependence on Mr Kennedy and pressure that the wedding would not proceed without an agreement. The High Court unanimously held that the agreements should be set aside for unconscionable conduct. A majority also found undue influence.
The case concerned the circumstances in which agreements were made, rather than a routine adjustment after separation because someone’s income changed. For couples considering replacement documents, it illustrates why independent advice does not make pressure or exploitation irrelevant. Allow a genuine opportunity to consider the proposal and obtain advice; a signature alone does not resolve every enforceability issue.
Changing final property consent orders
Property consent orders are intended to provide finality. Where all parties to the original proceedings consent, the Court has power to vary or set aside the orders and, where appropriate, substitute new orders. A private understanding between former partners does not itself amend the court record. The correct application and proposed orders still need to be prepared.
Without consent, sections 79A and 90SN provide limited grounds for reopening property orders. Examples include a miscarriage of justice involving fraud or non-disclosure, later circumstances making implementation impracticable, certain defaults, or exceptional circumstances concerning a child that cause the required hardship. The statutory conditions and the Court’s discretion matter. Ordinary financial setbacks do not create a general right to redistribute assets already settled.
Distinguish changing the settlement from enforcing it. If the problem is an unpaid amount or a failure to sign transfer documents, enforcement may be the appropriate response. If the complaint concerns an error in the original decision, appeal rules and deadlines may instead be relevant. Early advice helps identify the correct remedy.
Maintenance orders have their own variation rules
Ongoing spousal or de facto maintenance orders may be varied, suspended or discharged under separate provisions. A change in either person’s financial circumstances can be relevant, subject to the applicable requirements. Evidence of income, expenses, health and earning capacity helps explain what has changed and why the existing amount may need reconsideration.
Legal Aid NSW’s maintenance guidance explains that an order must still be in force to be varied. A fully satisfied lump sum maintenance order cannot simply be reopened through the same process. Maintenance recorded in a financial agreement also requires analysis of that agreement; the rules for varying court orders do not automatically apply.
Changing parenting arrangements
A parenting plan is a written, signed and dated agreement about children’s arrangements, but it is not enforceable in the same way as a court order. Parents can agree on a new plan. Where orders already exist, obtain advice because a later parenting plan may affect their operation, subject to the orders and legislation. Consent orders are an option where enforceable revised arrangements are needed.
For contested reconsideration of final parenting orders, section 65DAAA requires the Court to consider whether circumstances have changed significantly and to be satisfied that reconsideration is in the child’s best interests. There is a separate pathway where all parties agree or consent to reconsideration. Any new parenting orders must still serve the child’s best interests. The Court’s guidance on changing parenting arrangements explains the available routes.
Before a contested parenting application, family dispute resolution and a section 60I certificate are generally required unless an exemption applies. Relevant exemptions include family violence, child abuse and urgency. An application for consent orders does not require that certificate. Raise safety concerns early so communications and the proposed process can be managed appropriately.
Keep child support separate
Changing parenting time or a property settlement does not automatically rewrite child support arrangements. Identify whether you have an administrative assessment, a limited agreement or a binding child support agreement. They have different rules. Services Australia explains that replacing or terminating a binding child support agreement generally requires another binding agreement, while court intervention and statutory ending events may also apply.
Limited agreements have different termination options. Report relevant care and income changes to Services Australia promptly and obtain advice about their effect. Do not assume that a private agreement to reduce payments has changed an assessed or enforceable liability.
Prepare a clear proposal and supporting evidence
Identify the exact clauses or orders you want changed, the proposed replacement terms and the reason. Assemble current financial records and relevant evidence rather than relying on general claims of unfairness. Consider negotiation or mediation where appropriate, while checking deadlines and ongoing obligations. Clear drafting should address commencement dates, arrears, implementation and any arrangements that remain in place.
CM Lawyers can advise on financial agreements, property orders and related family law issues. Contact our team with the existing documents before signing a replacement or stopping payments. This article provides general information, not advice about a particular agreement.
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