Maria Nati 

In Australia, a married woman can decide to either retain her maiden name or take on her husband’s surname after the wedding.  Although less common, a married man can take on his wife’s surname after the wedding.  Some couples choose to hyphenate both surnames and both partners change to this new surname.  Alternatively, only the woman uses the hyphenated surname.   In all these situations, it is advisable the couple discuss the matter of surnames openly and jointly decide on their approach, preferably before the wedding.

If you’ve decided to change your surname, you will need to notify all the relevant organisations requesting them to update their records and if applicable, issue you with new documents .  If you have changed your address since the wedding, then you should notify them of the new address at the same time.

Some organisations will request to sight the original Marriage Certificate issued by Births, Deaths & Marriages while others may accept a certified copy.  When you receive the official Marriage Certificate from Births, Deaths & Marriages, it's probably a good idea to have a number of copies certified by a Justice of the Peace in one go.  As a Justice of  the Peace myself, I would be more than happy to certify your official Marriage Certificate or other documents.  You can search for a NSW Justice of the Peace here. 

Below is a list of organisational groups that you may need to notify.  Before you begin, visit their website or call them to find out their process as each organisation is different.