There is no legal barrier to adults choosing to have the same surname, regardless of whether they are in any type of relationship. Doing so has no legal effect on the status of the relationship but it may remove a lot of practical difficulties, particularly for de facto couples (in such matters as hospital benefits, making contracts, obtaining a loan), simply because there is likely to be less explaining to do.
You can change your surname by applying to Births, Deaths and Marriages Victoria (contact details are at the end of this chapter). Information and forms may also be obtained and lodged via the Births, Deaths and Marriages website at www.bdm.vic.gov.au. (For further information, see Chapter 4.6: Changing your name.)
The surname of children of a de facto relationship is also discussed in Chapter 4.6: Changing your name. Note, however, that one parent cannot change the legal first name or surname of a child without the other parent’s To agree to something being done, to approve an action or arrangement. See also informed consent. or a An independent body that hears legal claims brought by parties and decides between them. Serious cases are heard by a judge and jury, or just a judge. Less-serious cases are heard by a magistrate. order. See ‘Registering children conceived with reproductive assistance and through surrogacy arrangements’, below, for information on registration of children born to same-sex parents.
In Zalsman & Blendall  FamCA 292, the applicant mother filed an initiating application seeking a change of surname for her four children. The mother wanted her children to adopt her surname and not have the surname of their biological father, Mr Blendall. At the time of the The time and place at which a court or tribunal hears the parties argue their case and makes a decision., the mother had sole parental responsibility of the children. Also, an A court order that prohibits a person harming or harassing another person. See also family violence intervention order;personal safety intervention order. was in force against the father due to significant domestic violence perpetrated by Mr Blendall. Material presented to a court to prove or disprove a fact. It can include what witnesses say as well as documents and other objects. was given by all four children that they wished to change their surname so they would no longer have a surname that they associated with an abusive past. As the court found that a change of surname was in the best interests of the children, it granted the orders sought.