Notice Of Intended Marriage
The first legal requirement for a marriage is completing a Notice of Intended Marriage or NOIM. You can download one from the Attorney General's Department of the Australian Government.
The NOIM must be with your celebrant at least a month and a day before your wedding (eg if your wedding is 1st November, your form must be with your celebrant by 30th September; if 6th March, the form is required by 5th February at the latest).
On the front of the form you write your names, your address, your dates of birth, your occupations as well as your parents/adoptive parents details, if known.
Your signatures on the back of the form must be witnessed by one of a specific group of authorised people (listed on the back of the NOIM) eg your celebrant.
Before a wedding can be conducted you MUST show your original birth certificate (or a certified copy) if born in Australia (or, if you were born overseas, your passport) and divorce papers or death certificate, if relevant.