Introduction
Many couples believe prenups only apply before a wedding. In Australian law this is not correct. Prenuptial agreements are Binding Financial Agreements and they can be entered before marriage during marriage and after separation. What matters is compliance with the Family Law Act 1975 and the quality of the legal process.
This guide explains how prenups created during marriage operate how courts assess them and how to ensure they remain binding in Australia in 2026.
For the main prenup overview see
https://www.adamsunited.com.au/prenup-australia-fixed-fee/
Are prenups created after marriage binding
Yes. Australian law specifically allows financial agreements during marriage. These agreements carry the same legal force as prenups created before the wedding. They are Binding Financial Agreements and must meet the same requirements.
Courts enforce them when
• the agreement complies with the Family Law Act
• each party received independent legal advice
• disclosure was complete and accurate
• the agreement was entered freely
• the agreement was fair at the time it was signed
Financial agreements during marriage follow the same rules as all Binding Financial Agreements.
Why couples choose prenups during marriage
Couples often create agreements during marriage for several reasons
• protecting a recent inheritance
• business restructuring
• purchase of a new property
• family pressure to secure assets
• increased financial contributions by one partner
• blended family planning
• minimising litigation risk if separation occurs
Agreements during marriage offer clarity and certainty at a time when finances change.
For professional guidance
https://www.adamsunited.com.au/binding-financial-agreements-prenups/
Legal requirements for prenups during marriage
Prenups created during marriage must satisfy the same mandatory elements as all Binding Financial Agreements.
Courts look for
• full and frank disclosure
• proper independent legal advice for each party
• compliant legal advice certificates
• fairness at the time of signing
• clear and correct drafting
• evidence of genuine negotiation
When these elements are met courts uphold agreements created during marriage just as they do prenups made beforehand.
What courts look for
Courts assess
• whether both parties understood the agreement
• whether the agreement was negotiated freely
• whether disclosure covered property, superannuation, and liabilities
• whether both parties had sufficient time to consider advice
• whether any pressure or emotional leverage was present
If the process was clean and compliant, courts respect the agreement.
Court information
https://www.fcfcoa.gov.au
How fairness is assessed
Fairness is assessed at the exact time the agreement was signed not years later.
Courts ask
• was the structure reasonable
• did each party understand the outcome
• did each party have proper advice
• was the agreement practical and workable
A well drafted agreement that reflects the financial circumstances at the time of signing is usually upheld.
Common reasons prenups during marriage fail
Prenups created during marriage can fail when
• advice certificates are incomplete
• disclosure is inaccurate
• a party did not understand the agreement
• the agreement was rushed
• the terms were significantly one sided without explanation
• the drafting does not comply with the Family Law Act
Legislation reference
https://www.legislation.gov.au/Series/C2004A01050
When to update or strengthen an existing prenup
It may be appropriate to update an agreement if
• a major asset is purchased
• a business expands
• an inheritance is received
• a child is born
• financial circumstances change
• there is a blended family situation
Updating ensures the agreement matches the current financial reality.
Do prenups created during marriage override court powers
Yes when valid.
A Binding Financial Agreement removes the usual power of the court to divide property.
Courts then rely on the agreement instead of determining property interests through their normal discretionary process.
This is why the agreement must be drafted and executed correctly.
Binding Financial Agreements Adams United Lawyers
We prepare
• agreements before marriage
• agreements during marriage
• agreements after separation
• independent legal advice for both parties
• full disclosure guidance
• fixed fee pricing
• nationwide service
FAQ Prenups After Marriage in Australia
Are prenups created during marriage legally binding in Australia
Yes. Prenups created during marriage are legally binding when they meet the requirements of the Family Law Act. Each party must receive independent legal advice there must be full disclosure and the agreement must be entered freely.
Why would a couple create a prenup after they are already married
Couples may create a prenup during marriage to protect an inheritance to clarify financial contributions to secure a business asset or to create certainty in blended family situations.
Do courts enforce prenups made during marriage
Yes. Courts enforce these agreements when the drafting is correct the advice is compliant the disclosure is full and the signing process was fair and free from pressure.
Can a prenup be updated after marriage
Yes. A prenup can be updated or replaced if financial circumstances change such as buying a new property receiving an inheritance starting a business or restructuring assets.
What makes a prenup created during marriage vulnerable to challenge
Common issues include incomplete disclosure lack of proper advice pressure at signing unfair terms at the time of signing or drafting that does not comply with the Family Law Act.
Is a prenup made during marriage stronger than relying on court decisions
A valid prenup prevents the court from using its usual powers to adjust property interests, which gives certainty and removes the risk of unpredictable outcomes in future proceedings.
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https://www.adamsunited.com.au/contact-us/
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