The definition of marriage is easy to understand on the surface. A couple gets engaged, throws a big wedding party, and cements their relationship legally. Marriage is the voluntary union of two people, but beyond the celebration, there are important legalities that every couple should understand.
Marriage is a legally and socially sanctioned union between two people that includes obligations related to property rights, support of children, and financial responsibilities. It is an institution that has served various economic and social purposes throughout history, and one that remains an important part of social and cultural life in Australia today. Whether you are planning to marry, questioning the validity of your current marriage, or navigating a separation, understanding what Australian law says about the definition of marriage is essential.
What Is the Legal Definition of Marriage in Australia?
The Marriage Act 1961 (Cth) governs marriages in Australia and contains the definition of marriage along with related matters. Section 5 of the Act defines “marriage” as the union of two people to the exclusion of all others, voluntarily entered into for life.
This definition was updated in December 2017 by the Marriage Amendment (Definition and Religious Freedoms) Act 2017, which changed the former definition from “the union of a man and a woman” to the more inclusive “union of two people.” Before 2004, there was in fact no codified definition of marriage in the Act at all. The institution of marriage remains an important part of social and cultural life despite a decline in marriage rates, and it continues to provide emotional security, intimacy, and a recognised legal framework for couples across Australia.
Breaking Down the Definition of Marriage: Key Terms Explained
“Union of two people”
The Act recognises that marriage can occur between any two people, regardless of sex or gender identity. The sex of either partner is irrelevant under the current law.
“To the exclusion of all others”
The Act recognises only a union of two people and does not recognise polygamous marriages or concubinage. Any such arrangement would not constitute a valid marriage under Australian law.
“Voluntarily entered”
A court can punish a person who forces another into marriage. It is an offence to force someone, through coercion, threat or deception, to marry. It is also an offence for the spouse who you are being forced to marry (if they are separate from the person forcing you) to go ahead with the marriage.
Sections 270.7A, 270.7B, 270.8 and 270.9 of the Criminal Code Act 1995 deal with these offences and provide that the maximum penalty is four years imprisonment, or seven years for an offence aggravated by the age of the victim, subjecting the victim to cruel, inhumane or degrading treatment, or putting the victim in danger of serious harm or death. The aggravating circumstances of these offences may occur wholly outside of Australia. A marriage entered into without valid consent becomes a void marriage. Hence, even arranged marriages should have valid consent from both potential spouses.
Same-Sex Marriage and the Definition of Marriage in Australia
The definition of marriage also extends to same-sex marriages. Although a vast majority recognise same-sex marriages as civil unions, in Australia, gender and sex no longer play any role in the right to marry. The Netherlands became the first country to legalise same-sex marriage in 2000, and Australia followed in 2017. Proponents of same-sex marriage have long argued it is a human rights issue, advocating for equal access to a major social institution. The legal recognition of same-sex unions through civil partnerships was crucial in the years prior to the 2017 change. In 2017, the Australian Marriage Law Postal Survey showed a clear majority of support for legalising same-sex marriage, and Parliament responded by passing the Marriage Amendment (Definition and Religious Freedoms) Act 2017.
Ever since the Marriage Act 1961 changes, same-sex couples can legally marry in Australia, irrespective of their sex or gender identity. The amendment also recognises overseas same-sex marriages if they fulfil all the requirements of a valid marriage. In addition, the Sex Discrimination Act 1984 (Cth) was amended to ensure that it is not unlawful discrimination for a minister of religion or religious marriage celebrant or chaplain to refuse to marry a couple based on the grounds of religious beliefs, sexuality or gender.
Legal Requirements for a Valid Marriage in Australia
Now that we know the definition of marriage, it is also important to understand the legal requirements for getting married in Australia. To be legally married, the parties must:
- Not be already married
- Not be marrying immediate family members such as a parent, grandparent, child, grandchild, brother or sister
- Be over the age of 18; those aged 16 or 17 will need court approval
- Understand what marriage means and freely agree to marry
- Give a Notice of Intended Marriage form to an authorised marriage celebrant at least one month and no more than 18 months before the wedding
- Be married by an authorised marriage celebrant, who may be a minister of religion registered under the Act, the Registrar of Marriages for the relevant state or territory, or a person authorised by the Commonwealth Attorney-General
A divorced or widowed person must produce evidence of the divorce or a death certificate to prove they are not currently married. Parties do not have to be Australian citizens or permanent residents to marry in Australia.
When Is a Marriage Void in Australia?
A marriage entered into in Australia is void (not valid or legally binding) if:
- Either party is already lawfully married (bigamy, polygamy)
- The parties are in an illegal relationship, meaning a relationship with a direct ancestor or descendant or sibling (whether full or half sibling), including adopted siblings
- The marriage was not solemnised by an authorised celebrant
- There is no consent, due to duress, fraud, mistake as to identity, mistake as to the nature of the ceremony, or mental incapacity
- The parties are below the marriageable age (child marriage)
A marriage celebrant who fails to hold a valid licence will not always result in a void marriage. Section 48(3) of the Marriage Act 1961 provides that a marriage will still be declared valid where the married couple believed that the celebrant was authorised to perform the ceremony and their genuine intention was to be lawfully wedded.
Legal Effects of Marriage in Australia
The legal effects of marriage are just as important as the definition of marriage itself. Marriage in Australia has a number of significant legal consequences:
- There is no legal obligation to change your surname on marriage. A person who marries can choose to take their spouse’s surname, but should update their identification documents and notify relevant government departments.
- Marriage in Australia automatically revokes any previous Wills unless the Will was specifically made in contemplation of the marriage. Neither separation nor divorce automatically revokes a Will; however, divorce removes any gift or power to the former spouse. To learn more about Wills, click here.
- Married spouses are automatically recognised as each other’s next of kin, granting rights in emergencies and with respect to inheritance where no Will exists.
- The amount of tax a person pays changes once they are married; you must notify the Taxation Office of the change.
Definition of Marriage Versus De Facto Relationships in Australia
De facto partners who live together cohabitate on a domestic basis without the benefit of marriage. Both arrangements involve couples dealing with debt responsibilities, division of assets, and children. However, there is more than meets the eye:
- Marriage is a legal union between two persons. A de facto relationship occurs between two parties living together in the same household without the benefit of marriage.
- A couple who will marry must obtain a marriage licence. De facto couples do not require any formal legal steps to start cohabiting.
- Marriage provides recognition both interstate and internationally, while registering a de facto relationship will only gain recognition within Australia.
- Should a marriage end, it requires the formal process of filing for divorce or annulment. De facto couples who have registered their relationship must revoke that registration, which can be an informal process depending on the terms of a Cohabitation Agreement.
- If a spouse in a marriage dies without leaving a Will, the surviving spouse will generally inherit part of the estate. However, the surviving partner in a de facto relationship may not have an automatic right to any inheritance where there is no Will.
The Family Law Act 1975 treats de facto relationships as marriages for the purpose of recognising the rights of parties at a breakup.
Overseas Marriages Recognised in Australia
Australia will legally recognise an overseas marriage if it meets the following requirements:
- The law of the country in which you married considered your marriage valid, and
- Australian law would recognise the marriage as valid if it took place in Australia
There is no legal requirement to register an overseas marriage in Australia. However, you will need evidence of the marriage, such as a marriage certificate from the country where it took place. As same-sex marriages are already recognised as valid under Australian law, they are included in overseas marriages recognised in Australia.
How Does a Marriage End in Australia?
A marriage in Australia can only be dissolved by divorce after a separation period of at least 12 months, as required under the Family Law Act 1975. A marriage may also end through death or annulment. In Australia, a court can annul a marriage if it finds that it is invalid, provided certain conditions are met. The grounds for annulment are strict, and most people who wish to end their marriage will need to apply for a divorce.
Approximately 40 per cent of marriages end in divorce, with higher risks for younger couples or those from divorced families. This is precisely why understanding your legal rights and responsibilities before and during marriage matters so much.
Taking Care of Your Marriage
Knowing the definition of marriage does not automatically make you the perfect partner. Marriage is largely influenced by the shared values and commitment levels of the partners involved. Successful couples speak fondly about each other and use “we” more than “I” when discussing their relationship. Couples that have open discussions about their financial commitments and personal concerns tend to be the most satisfied. Partners who assume their spouses are doing their best and remain empathetic tend to build stronger marriages over time.
Never stop striving to be better for yourself and your partner. Being in married life changes a great deal, and it takes a different level of maturity, confidence, and intelligence to commit fully. It is not a game, but a lifetime commitment to work together as a team to tackle any challenge.
Frequently Asked Questions About the Definition of Marriage in Australia
What is the current legal definition of marriage in Australia?
Under Section 5 of the Marriage Act 1961 (Cth), marriage is defined as “the union of two people to the exclusion of all others, voluntarily entered into for life.” This definition has applied since the 2017 amendment.
When did Australia change the definition of marriage?
Australia changed the definition of marriage in December 2017 following the Australian Marriage Law Postal Survey, in which a majority of Australians voted in favour of same-sex marriage. The Marriage Amendment (Definition and Religious Freedoms) Act 2017 replaced the former definition of “the union of a man and a woman.”
What are the legal requirements to get married in Australia?
Both parties must be over 18 (or have court approval if aged 16 or 17), not already married, not in a prohibited family relationship, freely consent to the marriage, give a Notice of Intended Marriage at least one month before the wedding, and be married by an authorised celebrant.
What makes a marriage void in Australia?
A marriage is void in Australia if either party is already married, the parties are in a prohibited relationship, there is no valid consent, the marriage was not solemnised by an authorised celebrant, or either party is below the legal age of marriage.
How is marriage different from a de facto relationship in Australia?
Marriage requires a formal legal process to enter and exit, provides broader recognition both nationally and internationally, and automatically grants rights including inheritance and next-of-kin status. A de facto relationship requires no formal steps to begin. However, the Family Law Act 1975 treats de facto relationships similarly to marriages in property and parenting matters upon separation.
Can an overseas marriage be recognised in Australia?
Yes, an overseas marriage will generally be recognised in Australia if it was valid under the laws of the country where it took place and would also be valid if it had been performed in Australia. This includes same-sex marriages performed overseas.
How long does a couple need to be separated before applying for divorce in Australia?
Under the Family Law Act 1975, a couple must be separated for at least 12 months before applying for a divorce in Australia.
What happens to a Will after marriage in Australia?
Marriage automatically revokes any previous Wills unless the Will was specifically made in contemplation of the marriage. It is important for married couples to update their Wills to ensure their wishes are properly documented and legally protected.
Seeking Legal Advice From Expert Family Lawyers
Did you get the definition of marriage you were looking for in this article? Marriages are not for everyone, but for people who do want to marry, staying informed about the legalities and being ready to commit fully is essential. Whether you are planning to get married and want to ensure your marriage will be valid, or the status of your marriage is being questioned, JB Solicitors is here to help.
JB Solicitors has a leading team of experienced family lawyers. We can help with the preparation of documents for marriage and provide legal advice on any concerns you have regarding marriage or other family law matters. Should your marriage encounter difficulties, we can help with property settlement and parenting matters.
Contact us today if you need help with your family law matter.
